wip text edit GUI (TODO: del/ins in the middle, entering space at the end)

.gitignore

@@ -3,3 +3,4 @@ cmake-build-debug
 build/
 .idea/
 sdkconfig.old
+.~lock*

README.md

@@ -1,5 +1,5 @@
-# Hello World Example
+# Breadflow
 
-Starts a FreeRTOS task to print "Hello World"
+is a toaster oven mod with a thermistor, SSR and ESP32.
 
-See the README.md file in the upper level 'examples' directory for more information about examples.
+It can bake bread or reflow PCBs.

aseprite_c/font/ico2h.rs

@@ -0,0 +1,56 @@
+use std::fs;
+use std::process::Command;
+use std::string::ToString;
+
+fn main() {
+    for entry in fs::read_dir(".").unwrap() {
+        let entry = entry.unwrap();
+        let path = entry.path();
+        
+        if !path.display().to_string().ends_with(".ico") {
+            continue;
+        }
+        
+        let name = path.file_stem().unwrap().to_str().unwrap();
+        
+        Command::new("/bin/convert").arg(&path).arg("./tmp.xbm").output().unwrap();
+        
+        let content = fs::read_to_string("./tmp.xbm").unwrap();
+        
+        let a = content.find('{').unwrap() + 1;
+        let b = content.find('}').unwrap();
+        
+        let bytes = &content[a..b].trim();
+        
+        let bytes = bytes.split(",")
+            .map(|s| s.trim())
+            .filter(|s| !s.is_empty())
+            .map(|s| u8::from_str_radix(&s[2..], 16).unwrap())
+            .collect::<Vec<_>>();
+        
+        assert!(bytes.len() == 8);
+        
+        let mut columns : [u8; 5] = [0,0,0,0,0];
+        
+        for (n, r) in bytes.iter().enumerate() {
+          for i in 0..5 {
+            if 0 != *r & (1<<i) {
+              columns[i] |= 1 << n;
+            }
+          } 
+        }        
+        
+        fn testchar(c : char) -> bool {
+          c.is_alphanumeric() || c=='_'
+        }
+        
+        let mut name = name.replace(|c:char|!testchar(c), "_");
+        if !name.starts_with(testchar) {
+          name = format!("_{}", name);
+        }
+        
+        println!("const uint8_t {}[5] = {{ {} }};", name, columns.iter().map(|c| format!("{:#04x}", !c)).collect::<Vec<_>>().join(", "));
+    }
+    
+    let _ = fs::remove_file("./tmp.xbm");
+}

aseprite_c/graphics/bitmaps.c

@@ -0,0 +1,124 @@
+#include "bitmaps.h"
+#include <stddef.h>
+#include <string.h>
+
+
+/* 21x22: no_flame */
+// ········██····█······
+// ·········██···██·····
+// ··········██·········
+// ··········███········
+// ·····█····███···█····
+// ···██····████··███···
+// ··██···█████··███····
+// ··█···█████··███·····
+// ·██··█████··███······
+// ·█··█████··███·······
+// ·█··████··███··█·····
+// ····███··███··███····
+// ·····█··███···███··█·
+// ·······███··█████··██
+// ·█····███··███████··█
+// █····███···███████···
+// ██··███··█··██████···
+// █··███··██···█████···
+// ··███··███···█████···
+// ·███··██·····█·███···
+// ███··█·········██····
+// ·█··███·······██·····
+static const uint8_t G_NO_FLAME_BYTES[] = { 0x00, 0x00, 0xc0, 0x60, 0x20, 0x10, 0x80, 0xc0, 0xc1, 0xe3, 0xfe, 0x7c, 0x38, 0x80, 0xc3, 0xe2, 0x70, 0x20, 0x00, 0x00, 0x00, 0x80, 0x47, 0x01, 0x00, 0x0e, 0x9f, 0xcf, 0xe7, 0x73, 0x39, 0x1c, 0xce, 0xe7, 0xe3, 0xf9, 0xfc, 0xf8, 0xc0, 0x00, 0x30, 0x60, 0x13, 0x39, 0x1c, 0x0e, 0x27, 0x33, 0x29, 0x0c, 0x06, 0x07, 0x00, 0x00, 0x01, 0x0f, 0x27, 0x3f, 0x1f, 0x0f, 0x00, 0x00, 0x00 };
+
+/* 21x22: flame */
+// ········██····█······
+// ·········██···██·····
+// ··········██·········
+// ··········███········
+// ·····█····███········
+// ···██····█████···█···
+// ··██···███████··█····
+// ··█···███████··██····
+// ·██··████████·██·····
+// ·█··████████··██·····
+// ·█··████████·███·····
+// ····████████·████····
+// ·····████·███·███··█·
+// ······███·███████··██
+// ·█·····██··███████··█
+// █·······██·███████···
+// ██·····███··██████···
+// █████·████···█████···
+// ·█████████···█████···
+// ··██████·····█·███···
+// ···███·········██····
+// ····███·······██·····
+static const uint8_t G_FLAME_BYTES[] = { 0x00, 0x00, 0xc0, 0x60, 0x20, 0x10, 0x80, 0xc0, 0xc1, 0xe3, 0xfe, 0xfc, 0xf8, 0x60, 0x03, 0x82, 0xc0, 0x20, 0x00, 0x00, 0x00, 0x80, 0x47, 0x01, 0x00, 0x0e, 0x1f, 0x3f, 0x7f, 0xff, 0x8f, 0x3f, 0xff, 0xf1, 0xec, 0xff, 0xff, 0xf8, 0xc0, 0x00, 0x30, 0x60, 0x03, 0x07, 0x0e, 0x1e, 0x3e, 0x3c, 0x2e, 0x0f, 0x07, 0x07, 0x00, 0x00, 0x01, 0x0f, 0x27, 0x3f, 0x1f, 0x0f, 0x00, 0x00, 0x00 };
+
+/* 84x48: boot_logo */
+// ····················································································
+// ·····································································████████·······
+// ························································█████████████····█···██·····
+// ···················█·······························█████····█·███·····███······█····
+// ······█·█····································██████···██·█████··███████·········█···
+// ·······█······························███████····██·█████·█·······███··········█····
+// ······█·█······················███████·····███·███████··██···················██·····
+// ···························██████·██·███·███·███████████·████·············███·······
+// ······················████████████·██··███··█████████·█████·············██·██·······
+// ··················█████·██·████···█·████···███████·███·············█████···██·······
+// ·············███████████·█████████████···██·······█············█████··█·█·█·██······
+// ············██████████·██████████··███████·················█████··█·██·█···███······
+// ·········██████··█··████·██·███···████·█···············████···█··███··█······██·····
+// ······███·████████████████████··██················█████··█···█·█·█···········█·█····
+// ···███████····················██··············████·█····█·····█················█····
+// ····██··························█·············█···█····██······················█····
+// ··██·····························█·······█·█·█···█····██·······················█····
+// ·█······························█·······█·█·█···█·█····························█····
+// ·█····························██·······█·█·█·····█····················█········█····
+// ··██······················████·█·█·█··█·······························█······█··█···
+// ····████···················█··█·█·█··█································█······█··█···
+// ·······█···················██·█·██··························█·········█······█··█···
+// ·······█····················█·██······█·····················█··········█·····█··█···
+// ·······█····················█·█········█··········█··········█·········█·····███····
+// ········█···················█··········█···········█·········█·····██████████·······
+// ········█····················█·········█············█·········█·███·················
+// ········█····················█··········█···········█·······████····················
+// ········█·····················█·········█············█·█████························
+// ········█······················█·········█·········████·····························
+// ········█·······················█········█····█████···██················█·█·········
+// ·········█······················█·········█·██···························█··········
+// ·········█······················█·······████····························█·█·········
+// ·········█······················█····███·····················█······················
+// ·········█·······················████·······················███·····················
+// ·········█·····················███···························█······················
+// ·········█········██████████████····················································
+// ··········█·██████·····························································█····
+// ···········█····························································█······█····
+// ··························································█············█·······█····
+// ··████·································█··················█······██····█··█····█····
+// ··█···█···██████···█████████····█·····███████···███████···█·····█··█····█·██····█···
+// ··█···█··██·····█·█·█··········█·█······█····█·█·█·······█·····█····█···█··█····█···
+// ··████····█·····██··█··········█·█······█····█···██████··█·····█····█···█··█····█···
+// ··█···█···██████··███████·····█···█·····█···█··███·······█·····█···█·····█·██···█···
+// ··█····█··██········█········███████····█··█·····█·······█······█·█······█·█·█·█····
+// ··█···█···█·██······█·····██··█····█··█████······█········█████··█········█···█·····
+// ██████····█···███····█████···█·····██············█··································
+// ··········█·····█···································································
+static const uint8_t G_BOOT_LOGO_BYTES[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x50, 0x20, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x80, 0x80, 0x80, 0xc0, 0xc0, 0x40, 0xc0, 0xc0, 0x40, 0xc0, 0xa0, 0xa0, 0x20, 0xa0, 0xa0, 0xe0, 0x60, 0xd0, 0x90, 0xd0, 0xd0, 0xf0, 0xf0, 0xc8, 0xe8, 0xe8, 0xb8, 0xb8, 0x64, 0xd4, 0xb4, 0x94, 0x9c, 0x14, 0x0c, 0x0c, 0x1c, 0x14, 0x34, 0x34, 0x34, 0x12, 0x1a, 0x0a, 0x0a, 0x06, 0x82, 0x82, 0x82, 0x44, 0x44, 0x28, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0xc0, 0xc0, 0x60, 0x60, 0x60, 0x50, 0x30, 0x30, 0x38, 0x3c, 0x3c, 0x2c, 0x2c, 0x3c, 0x2e, 0x2e, 0x3e, 0x3e, 0x37, 0x3d, 0x2b, 0x3f, 0x3d, 0x2f, 0x3f, 0x3f, 0x5f, 0x4d, 0xad, 0x25, 0x16, 0x1d, 0x1f, 0x1e, 0x0a, 0x1b, 0x09, 0x0d, 0x04, 0x02, 0x03, 0x03, 0xc3, 0x43, 0x43, 0x43, 0xa5, 0x63, 0x23, 0x22, 0x21, 0x91, 0xd1, 0x31, 0x11, 0x08, 0x08, 0x28, 0x58, 0x2c, 0x04, 0x34, 0x1c, 0x16, 0x0a, 0x0a, 0x16, 0x0a, 0x05, 0x01, 0x04, 0x0b, 0x0f, 0x3c, 0x10, 0xe0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x09, 0x09, 0x10, 0x10, 0x10, 0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x38, 0xe8, 0x08, 0xf4, 0x4c, 0x32, 0x29, 0x10, 0x08, 0x00, 0x10, 0x48, 0x84, 0x02, 0x05, 0x02, 0x05, 0x02, 0x01, 0x00, 0x00, 0x02, 0x05, 0x82, 0x00, 0x00, 0x00, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x60, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3c, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf8, 0x80, 0x87, 0x78, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3f, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x06, 0x08, 0x10, 0xe0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x8c, 0xb0, 0xc0, 0x80, 0x40, 0x40, 0x20, 0x20, 0x20, 0x20, 0x20, 0x11, 0x16, 0x18, 0x30, 0x28, 0x08, 0x08, 0x08, 0x08, 0x04, 0x05, 0x06, 0x04, 0x02, 0x02, 0x02, 0x01, 0x01, 0x01, 0x01, 0x01, 0xa1, 0x41, 0xa1, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x80, 0x80, 0x80, 0x00, 0x00, 0x00, 0x0f, 0x10, 0x20, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x0c, 0x05, 0x06, 0x02, 0x02, 0x02, 0x01, 0x01, 0x81, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xc0, 0x00, 0x02, 0x07, 0x02, 0x00, 0x00, 0x80, 0x80, 0x00, 0x00, 0x00, 0x00, 0xc0, 0x20, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0xf0, 0x00, 0x00, 0x00, 0x00, 0x40, 0x40, 0x7f, 0x44, 0x44, 0x44, 0x2b, 0x10, 0x00, 0x02, 0xff, 0x19, 0x29, 0x29, 0x49, 0x49, 0xc6, 0x04, 0x0a, 0x09, 0x3f, 0x49, 0x49, 0x49, 0x49, 0x41, 0x21, 0x21, 0x00, 0x50, 0x38, 0x16, 0x11, 0x16, 0x18, 0x70, 0x40, 0x00, 0x21, 0x21, 0x3f, 0x21, 0x21, 0x11, 0x09, 0x06, 0x00, 0x0a, 0x09, 0x7f, 0x05, 0x05, 0x05, 0x05, 0x05, 0x00, 0x00, 0x1e, 0x21, 0x20, 0x20, 0x20, 0x20, 0x0e, 0x11, 0x20, 0x10, 0x09, 0x06, 0x00, 0x00, 0x00, 0x07, 0x18, 0x21, 0x1f, 0x08, 0x10, 0x20, 0x10, 0x0f, 0x00, 0x00, 0x00 };
+
+static const struct BitmapImage bitmaps[] = { 
+    { .name="no_flame", .width=21, .height=22, .bytes=G_NO_FLAME_BYTES },
+    { .name="flame", .width=21, .height=22, .bytes=G_FLAME_BYTES },
+    { .name="boot_logo", .width=84, .height=48, .bytes=G_BOOT_LOGO_BYTES },
+    {}
+};
+
+const struct BitmapImage *Bitmap_Get(const char *name) {
+    const struct BitmapImage *ptr = &bitmaps[0];
+    while (ptr->name) {
+        if (0 == strcmp(ptr->name, name)) {
+            return ptr;
+        }
+        ptr++;
+    }
+    return NULL;
+}
+    

aseprite_c/graphics/gfx2h.rs

@@ -0,0 +1,172 @@
+use std::fs::{self,OpenOptions};
+use std::process::Command;
+use std::string::ToString;
+use std::io::Write;
+
+fn main() {
+    let mut c_constants = Vec::new();
+    let mut c_table = Vec::new();
+
+    for entry in fs::read_dir(".").unwrap() {
+        let entry = entry.unwrap();
+        let path = entry.path();        
+        
+        if !path.display().to_string().ends_with(".ico") {
+            continue;
+        }
+        
+        let name = path.file_stem().unwrap().to_str().unwrap();
+        
+        Command::new("/bin/convert").arg(&path).arg("./tmp.xbm").output().unwrap();
+        
+        let content = fs::read_to_string("./tmp.xbm").unwrap();
+        
+        println!("\n------------------------------------------------------------------------\n");
+        
+        println!("{}", content);
+        
+        let mut lines = content.lines();
+        let l1 = lines.nth(0).unwrap();
+        let l2 = lines.nth(0).unwrap();
+        
+        let w : usize = l1[l1.find("width").unwrap()+6..].parse().unwrap();        
+        let h : usize = l2[l2.find("height").unwrap()+7..].parse().unwrap();
+                
+        let a = content.find('{').unwrap() + 1;
+        let b = content.find('}').unwrap();        
+        let bytes = &content[a..b].trim();
+        
+        let bytes = bytes.split(",")
+            .map(|s| s.trim())
+            .filter(|s| !s.is_empty())
+            .map(|s| ! u8::from_str_radix(&s[2..], 16).unwrap())
+            .collect::<Vec<_>>();
+            
+            
+        print!("---SOURCE--\n");
+        for y in 0..h {
+            for x in 0..(w-1)/8+1 {
+                for xx in 0..8 {                
+                    if (bytes[y*(((w-1)/8+1)) + x] & (1u8 << xx)) != 0 {
+                        print!("█");
+                    } else {
+                        print!("·");
+                    }
+                }
+            }
+             print!("\n");
+        }
+        println!("---\n");
+            
+        println!("name {},\nw {} h {},\nbytes {}", name, w, h, bytes.iter().map(|c| format!("{:#04x}", c)).collect::<Vec<_>>().join(", "));
+        
+        let bit_xy = |x : usize, y : usize| {
+            let xx = x / 8;
+            let nthbit = x % 8;
+            let n = y*((w-1)/8+1) + xx;
+            if n >= bytes.len() {
+                0u8
+            } else {            
+                let r = ((bytes[n] & (1 << nthbit)) >> nthbit) as u8;
+                r
+            }
+        };
+        
+        let result_cols = w;
+        let result_rows = ((h-1)/8)+1;
+        
+        let mut result = Vec::new();
+        
+        for y in 0..result_rows {
+            for x in 0..result_cols {
+                let mut buf = 0u8;
+                for yy in 0..8 {
+                    buf |= bit_xy(x, y * 8 + yy) << yy;
+                }
+                result.push(buf);
+            }
+        }
+        
+        //println!("final bytes {}", result.iter().map(|c| format!("{:#04x}", c)).collect::<Vec<_>>().join(", "));
+        
+        let mut render = String::new();
+        print!("---\n");
+        for y in 0..result_rows {
+            for yy in 0..8 {
+                if y*8+yy >= h {
+                    break;
+                }
+                render.push_str("// ");
+                for x in 0..result_cols {
+                    if (result[y*result_cols + x] & (1u8 << yy)) != 0 {
+                        print!("█");
+                        render.push_str("█");
+                    } else {
+                        print!("·");
+                        render.push_str("·");
+                    }
+                }
+                if yy == 7 {
+                    print!("/ end of byte row");
+                }
+                render.push_str("\n");
+                print!("\n");
+            }
+        }
+        println!("---\n");
+        
+        fn testchar(c : char) -> bool {
+          c.is_alphanumeric() || c=='_'
+        }
+        
+        let mut name = name.replace(|c:char|!testchar(c), "_");
+        if !name.starts_with(testchar) {
+          name = format!("_{}", name);
+        }
+        
+        c_constants.push(format!("\n/* {}x{}: {} */\n{}static const uint8_t G_{}_BYTES[] = {{ {} }};", 
+            w,h,
+            name,
+            render,
+            name.to_uppercase(),
+            result.iter().map(|c| format!("{:#04x}", c)).collect::<Vec<_>>().join(", ")
+        ));
+        
+        c_table.push(format!("{{ .name=\"{}\", .width={}, .height={}, .bytes=G_{}_BYTES }}", 
+            name,
+            w, h,
+            name.to_uppercase()
+        ));
+    }
+    
+    let c_source = format!(r##"#include "bitmaps.h"
+#include <stddef.h>
+#include <string.h>
+
+{}
+
+static const struct BitmapImage bitmaps[] = {{ 
+    {},
+    {{}}
+}};
+
+const struct BitmapImage *Bitmap_Get(const char *name) {{
+    const struct BitmapImage *ptr = &bitmaps[0];
+    while (ptr->name) {{
+        if (0 == strcmp(ptr->name, name)) {{
+            return ptr;
+        }}
+        ptr++;
+    }}
+    return NULL;
+}}
+    "##, 
+        c_constants.join("\n"),
+        c_table.join(",\n    ")
+    );
+    
+    let mut f = OpenOptions::new().write(true).create(true).truncate(true).open("./bitmaps.c").unwrap();
+    f.write(c_source.as_bytes()).unwrap();
+    
+    let _ = fs::remove_file("./tmp.xbm");
+}

components/common_utils/CMakeLists.txt

@@ -0,0 +1,8 @@
+set(COMPONENT_ADD_INCLUDEDIRS include)
+
+set(COMPONENT_SRCDIRS
+        "src")
+
+#set(COMPONENT_REQUIRES)
+
+register_component()

components/common_utils/README.txt

@@ -0,0 +1,2 @@
+General purpose, mostly platofrm-idependent utilities
+that may be used by other components.

components/common_utils/component.mk

@@ -0,0 +1,3 @@
+
+COMPONENT_SRCDIRS := src
+COMPONENT_ADD_INCLUDEDIRS := include

components/common_utils/include/common_utils/base16.h

@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2010 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#ifndef BASE16_H_
+#define BASE16_H_
+
+#include <stdint.h>
+#include <string.h>
+
+/**
+ * Calculate length of base16-encoded data
+ * @param raw_len Raw data length
+ * @return Encoded string length (excluding NUL)
+ */
+static inline size_t base16_encoded_len(size_t raw_len) {
+	return (2 * raw_len);
+}
+
+/**
+ * Calculate maximum length of base16-decoded string
+ * @param encoded Encoded string
+ * @return Maximum length of raw data
+ */
+static inline size_t base16_decoded_max_len(const char *encoded) {
+	return ((strlen(encoded) + 1) / 2);
+}
+
+/**
+ * Base16-encode data
+ *
+ * The buffer must be the correct length for the encoded string.  Use
+ * something like
+ *
+ *     char buf[ base16_encoded_len ( len ) + 1 ];
+ *
+ * (the +1 is for the terminating NUL) to provide a buffer of the
+ * correct size.
+ *
+ * @param raw Raw data
+ * @param len Length of raw data
+ * @param encoded Buffer for encoded string
+ */
+extern void base16_encode(uint8_t *raw, size_t len, char *encoded);
+
+/**
+ * Base16-decode data
+ *
+ * The buffer must be large enough to contain the decoded data.  Use
+ * something like
+ *
+ *     char buf[ base16_decoded_max_len ( encoded ) ];
+ *
+ * to provide a buffer of the correct size.
+ * @param encoded Encoded string
+ * @param raw Raw data
+ * @return Length of raw data, or negative error
+ */
+extern int base16_decode(const char *encoded, uint8_t *raw);
+
+#endif /* BASE16_H_ */

components/common_utils/include/common_utils/datetime.h

@@ -0,0 +1,131 @@
+/**
+ * TODO file description
+ * 
+ * Created on 2019/09/13.
+ */
+
+#ifndef CSPEMU_DATETIME_H
+#define CSPEMU_DATETIME_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+enum weekday {
+    MONDAY = 1,
+    TUESDAY,
+    WEDNESDAY,
+    THURSDAY,
+    FRIDAY,
+    SATURDAY,
+    SUNDAY
+};
+_Static_assert(MONDAY==1, "enum weekday numbering Mon");
+_Static_assert(SUNDAY==7, "enum weekday numbering Sun");
+
+enum month {
+    JANUARY = 1,
+    FEBRUARY,
+    MARCH,
+    APRIL,
+    MAY,
+    JUNE,
+    JULY,
+    AUGUST,
+    SEPTEMBER,
+    OCTOBER,
+    NOVEMBER,
+    DECEMBER
+};
+_Static_assert(JANUARY==1, "enum month numbering Jan");
+_Static_assert(DECEMBER==12, "enum month numbering Dec");
+
+/** Abbreviated weekday names */
+extern const char *DT_WKDAY_NAMES[];
+/** Full-length weekday names */
+extern const char *DT_WKDAY_NAMES_FULL[];
+/** Abbreviated month names */
+extern const char *DT_MONTH_NAMES[];
+/** Full-length month names */
+extern const char *DT_MONTH_NAMES_FULL[];
+
+typedef struct datetime {
+    uint16_t year;
+    enum month month;
+    uint8_t day;
+    uint8_t hour;
+    uint8_t min;
+    uint8_t sec;
+    enum weekday wkday; // 1=monday
+} datetime_t;
+
+// Templates for printf
+#define DT_FORMAT_DATE   "%d/%d/%d"
+#define DT_SUBS_DATE(dt) (dt).year, (dt).month, (dt).day
+
+#define DT_FORMAT_TIME   "%d:%02d:%02d"
+#define DT_SUBS_TIME(dt) (dt).hour, (dt).min, (dt).sec
+
+#define DT_FORMAT_DATE_WK   DT_FORMAT_WK " " DT_FORMAT_DATE
+#define DT_SUBS_DATE_WK(dt) DT_SUBS_WK(dt), DT_SUBS_DATE(dt)
+
+#define DT_FORMAT_WK   "%s"
+#define DT_SUBS_WK(dt) DT_WKDAY_NAMES[(dt).wkday]
+
+#define DT_FORMAT_DATE_TIME   DT_FORMAT_DATE " " DT_FORMAT_TIME
+#define DT_SUBS_DATE_TIME(dt) DT_SUBS_DATE(dt), DT_SUBS_TIME(dt)
+
+#define DT_FORMAT   DT_FORMAT_DATE_WK " " DT_FORMAT_TIME
+#define DT_SUBS(dt) DT_SUBS_DATE_WK(dt), DT_SUBS_TIME(dt)
+
+// base century for two-digit year conversions
+#define DT_CENTURY 2000
+// start year for weekday computation
+#define DT_START_YEAR 2019
+// January 1st weekday of DT_START_YEAR
+#define DT_START_WKDAY TUESDAY
+// max date supported by 2-digit year RTC counters (it can't check Y%400==0 with only two digits)
+#define DT_END_YEAR 2399
+
+typedef union __attribute__((packed)) {
+    struct __attribute__((packed)) {
+        uint8_t ones : 4;
+        uint8_t tens : 4;
+    };
+    uint8_t byte;
+} bcd_t;
+_Static_assert(sizeof(bcd_t) == 1, "Bad bcd_t len");
+
+/** Check if a year is leap */
+static inline bool is_leap_year(int year)
+{
+    return year % 400 == 0 || (year % 4 == 0 && year % 100 != 0);
+}
+
+/**
+ * Check if a datetime could be valid (ignores leap years)
+ *
+ * @param[in] dt
+ * @return basic validations passed
+ */
+bool datetime_is_valid(const datetime_t *dt);
+
+/**
+ * Set weekday based on a date in a given datetime
+ *
+ * @param[in,out] dt
+ * @return success
+ */
+bool datetime_set_weekday(datetime_t *dt);
+
+/**
+ * Get weekday for given a date
+ *
+ * @param year - year number
+ * @param month - 1-based month number
+ * @param day - 1-based day number
+ * @return weekday
+ */
+enum weekday date_weekday(uint16_t year, enum month month, uint8_t day);
+
+
+#endif //CSPEMU_DATETIME_H

components/common_utils/include/common_utils/hexdump.h

@@ -0,0 +1,19 @@
+/**
+ * @file
+ * @brief A simple way of dumping memory to a hex output
+ *
+ * \addtogroup Hexdump
+ *
+ * @{
+ */
+
+
+#include <stdio.h>
+
+#define HEX_DUMP_LINE_BUFF_SIZ  16
+
+extern void hex_dump(FILE * fp,void *src, int len);
+extern void hex_dump_buff_line(FILE *fp, int addr_size, unsigned pos, char *line, unsigned len);
+/**
+ * }@
+ */

components/common_utils/include/common_utils/utils.h

@@ -0,0 +1,101 @@
+/**
+ * General purpose, platform agnostic, reusable utils
+ */
+
+#ifndef COMMON_UTILS_UTILS_H
+#define COMMON_UTILS_UTILS_H
+
+#include <stdbool.h>
+#include <stdint.h>
+
+#include "base16.h"
+#include "datetime.h"
+#include "hexdump.h"
+
+/** Convert a value to BCD struct */
+static inline bcd_t num2bcd(uint8_t value)
+{
+    return (bcd_t) {.ones=value % 10, .tens=value / 10};
+}
+
+/** Convert unpacked BCD to value */
+static inline uint8_t bcd2num(uint8_t tens, uint8_t ones)
+{
+    return tens * 10 + ones;
+}
+
+/**
+ * Append to a buffer.
+ *
+ * In case the buffer capacity is reached, it is reverted to the previous length (by replacing the NUL byte)
+ * and NULL is returned.
+ *
+ * @param buf - buffer position to append at; if NULL is given, the function immediately returns NULL.
+ * @param appended - string to append
+ * @param pcap - pointer to a capacity variable
+ * @return the new end of the string (null byte); use as 'buf' for following appends
+ */
+char *append(char *buf, const char *appended, size_t *pcap);
+
+/**
+ * Append, re-allocating as needed.
+ *
+ * @param head - pointer to heap buffer head, may be updated on realloc.
+ * @param size - string size pointer, may be updated on realloc.
+ * @param appended - string to append
+ * @return false on alloc error
+ */
+bool append_realloc(char **head, size_t *cap, const char *appended);
+
+/**
+ * Test if a file descriptor is valid (e.g. when cleaning up after a failed select)
+ *
+ * @param fd - file descriptor number
+ * @return is valid
+ */
+bool fd_is_valid(int fd);
+
+/**
+ * parse user-provided string as boolean
+ *
+ * @param str
+ * @return is true
+ */
+bool parse_boolean_arg(const char *str);
+
+/**
+ * complementary function to parse_boolean_arg() that matches strings
+ * meaning 'false'. Can be used together with the positive version
+ * in case there can be other values as well.
+ *
+ * @param str
+ * @return is false
+ */
+bool parse_boolean_arg_false(const char *str);
+
+/** Check equality of two strings; returns bool */
+#define streq(a, b) (strcmp((const char*)(a), (const char*)(b)) == 0)
+
+/** Check prefix equality of two strings; returns bool */
+#define strneq(a, b, n) (strncmp((const char*)(a), (const char*)(b), (n)) == 0)
+
+/** Check if a string starts with a substring; returns bool */
+#define strstarts(a, b) strneq((a), (b), (int)strlen((b)))
+
+#ifndef MIN
+/** Get min of two numbers */
+#define MIN(a, b) ((a) > (b) ? (b) : (a))
+#endif
+
+#ifndef MAX
+/** Get max of two values */
+#define MAX(a, b) ((a) > (b) ? (a) : (b))
+#endif
+
+#ifndef STR
+#define STR_HELPER(x) #x
+/** Stringify a token */
+#define STR(x) STR_HELPER(x)
+#endif
+
+#endif //COMMON_UTILS_UTILS_H

components/common_utils/src/base16.c

@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2010 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <esp_log.h>
+
+static const char *TAG = "base16";
+
+void base16_encode(uint8_t *raw, size_t len, char *encoded) {
+	uint8_t *raw_bytes = raw;
+	char *encoded_bytes = encoded;
+	size_t remaining = len;
+
+	for (; remaining--; encoded_bytes += 2)
+		snprintf(encoded_bytes, 3, "%02X", *(raw_bytes++));
+
+}
+
+int base16_decode(const char *encoded, uint8_t *raw) {
+	const char *encoded_bytes = encoded;
+	uint8_t *raw_bytes = raw;
+	char buf[3];
+	char *endp;
+	size_t len;
+
+	while (encoded_bytes[0]) {
+		if (!encoded_bytes[1]) {
+			ESP_LOGE(TAG, "Base16-encoded string \"%s\" has invalid length\n",
+					encoded);
+			return -22;
+		}
+		memcpy(buf, encoded_bytes, 2);
+		buf[2] = '\0';
+		*(raw_bytes++) = strtoul(buf, &endp, 16);
+		if (*endp != '\0') {
+			ESP_LOGE(TAG,"Base16-encoded string \"%s\" has invalid byte \"%s\"\n",
+					encoded, buf);
+			return -22;
+		}
+		encoded_bytes += 2;
+	}
+	len = (raw_bytes - raw);
+	return (len);
+}

components/common_utils/src/common_utils.c

@@ -0,0 +1,85 @@
+#include <stdint.h>
+#include <string.h>
+#include <stdbool.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <assert.h>
+
+#include "common_utils/utils.h"
+
+char *append(char *buf, const char *appended, size_t *pcap)
+{
+    char c;
+    char *buf0 = buf;
+    size_t cap = *pcap;
+
+    if (buf0 == NULL) return NULL;
+    if (appended == NULL || appended[0] == 0) return buf0;
+
+    if (*pcap < strlen(appended)+1) {
+        return NULL;
+    }
+
+    while (cap > 1 && 0 != (c = *appended++)) {
+        *buf++ = c;
+        cap--;
+    }
+    assert(cap > 0);
+
+    *pcap = cap;
+    *buf = 0;
+    return buf;
+}
+
+bool append_realloc(char **head, size_t *cap, const char *appended) {
+    if (!head) return NULL;
+    if (!*head) return NULL;
+    if (!cap) return NULL;
+    if (!appended) return NULL;
+
+    size_t cursize = strlen(*head);
+    size_t needed = strlen(appended) + 1;
+    size_t remains = *cap - cursize;
+
+    if (remains < needed) {
+        size_t need_extra = needed - remains;
+        size_t newsize = *cap + need_extra;
+        char *new = realloc(*head, newsize);
+        if (!new) return false;
+        *head = new;
+        *cap = newsize;
+    }
+
+    strcpy(*head + cursize, appended);
+    return true;
+}
+
+bool fd_is_valid(int fd)
+{
+    return fcntl(fd, F_GETFD) != -1 || errno != EBADF;
+}
+
+bool parse_boolean_arg(const char *str)
+{
+    if (0 == strcasecmp(str, "on")) return true;
+    if (0 == strcmp(str, "1")) return true;
+    if (0 == strcasecmp(str, "yes")) return true;
+    if (0 == strcasecmp(str, "enable")) return true;
+    if (0 == strcasecmp(str, "en")) return true;
+    if (0 == strcasecmp(str, "y")) return true;
+    if (0 == strcasecmp(str, "a")) return true;
+
+    return false;
+}
+
+bool parse_boolean_arg_false(const char *str)
+{
+    if (0 == strcasecmp(str, "off")) return true;
+    if (0 == strcmp(str, "0")) return true;
+    if (0 == strcasecmp(str, "no")) return true;
+    if (0 == strcasecmp(str, "disable")) return true;
+    if (0 == strcasecmp(str, "dis")) return true;
+    if (0 == strcasecmp(str, "n")) return true;
+
+    return false;
+}

components/common_utils/src/datetime.c

@@ -0,0 +1,110 @@
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stddef.h>
+#include "common_utils/datetime.h"
+
+const char *DT_WKDAY_NAMES[] = {
+    [MONDAY] = "Mon",
+    [TUESDAY] = "Tue",
+    [WEDNESDAY] = "Wed",
+    [THURSDAY] = "Thu",
+    [FRIDAY] = "Fri",
+    [SATURDAY] = "Sat",
+    [SUNDAY] = "Sun"
+};
+
+const char *DT_WKDAY_NAMES_FULL[] = {
+    [MONDAY] = "Monday",
+    [TUESDAY] = "Tuesday",
+    [WEDNESDAY] = "Wednesday",
+    [THURSDAY] = "Thursday",
+    [FRIDAY] = "Friday",
+    [SATURDAY] = "Saturday",
+    [SUNDAY] = "Sunday"
+};
+
+const char *DT_MONTH_NAMES[] = {
+    [JANUARY] = "Jan",
+    [FEBRUARY] = "Feb",
+    [MARCH] = "Mar",
+    [APRIL] = "Apr",
+    [MAY] = "May",
+    [JUNE] = "Jun",
+    [JULY] = "Jul",
+    [AUGUST] = "Aug",
+    [SEPTEMBER] = "Sep",
+    [OCTOBER] = "Oct",
+    [NOVEMBER] = "Nov",
+    [DECEMBER] = "Dec"
+};
+
+const char *DT_MONTH_NAMES_FULL[] = {
+    [JANUARY] = "January",
+    [FEBRUARY] = "February",
+    [MARCH] = "March",
+    [APRIL] = "April",
+    [MAY] = "May",
+    [JUNE] = "June",
+    [JULY] = "July",
+    [AUGUST] = "August",
+    [SEPTEMBER] = "September",
+    [OCTOBER] = "October",
+    [NOVEMBER] = "November",
+    [DECEMBER] = "December"
+};
+
+static const uint16_t MONTH_LENGTHS[] = { /* 1-based, normal year */
+    [JANUARY]=31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+};
+_Static_assert(sizeof(MONTH_LENGTHS) / sizeof(uint16_t) == 13, "Months array length");
+
+static const uint16_t MONTH_YEARDAYS[] = { /* 1-based */
+    [JANUARY]=0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 // // days until 1st of month
+};
+_Static_assert(sizeof(MONTH_YEARDAYS) / sizeof(uint16_t) == 13, "Months array length");
+
+_Static_assert(MONDAY < SUNDAY, "Weekday ordering");
+
+bool datetime_is_valid(const datetime_t *dt)
+{
+    if (dt == NULL) return false;
+
+    // check month first to avoid out-of-bounds read from the MONTH_LENGTHS table
+    if (!(dt->month >= JANUARY && dt->month <= DECEMBER)) return false;
+
+    int monthlen = MONTH_LENGTHS[dt->month];
+    if (dt->month == FEBRUARY && is_leap_year(dt->year)) {
+        monthlen = 29;
+    }
+
+    return dt->sec < 60 &&
+           dt->min < 60 &&
+           dt->hour < 24 &&
+           dt->wkday >= MONDAY &&
+           dt->wkday <= SUNDAY &&
+           dt->year >= DT_START_YEAR &&
+           dt->year <= DT_END_YEAR &&
+           dt->day >= 1 &&
+           dt->day <= monthlen;
+}
+
+bool datetime_set_weekday(datetime_t *dt)
+{
+    dt->wkday = MONDAY; // prevent the validator func erroring out on invalid weekday
+    if (!datetime_is_valid(dt)) return false;
+    dt->wkday = date_weekday(dt->year, dt->month, dt->day);
+    return true;
+}
+
+enum weekday date_weekday(uint16_t year, enum month month, uint8_t day)
+{
+    uint16_t days = (DT_START_WKDAY - MONDAY) + (year - DT_START_YEAR) * 365 + MONTH_YEARDAYS[month] + (day - 1);
+
+    for (uint16_t i = DT_START_YEAR; i <= year; i++) {
+        if (is_leap_year(i) && (i < year || month > FEBRUARY)) days++;
+    }
+
+    return MONDAY + days % 7;
+}
+

components/common_utils/src/hexdump.c

@@ -0,0 +1,72 @@
+/*
+ * util.c
+ *
+ *  Created on: Aug 12, 2009
+ *      Author: johan
+ */
+
+// adapted from libgomspace
+
+#include <string.h>
+#include <stdio.h>
+#include "common_utils/hexdump.h"
+
+
+//! Dump memory to debugging output
+/**
+ * Dumps a chunk of memory to the screen
+ */
+void hex_dump(FILE * fp, void *src, int len) {
+	int i, j=0, k;
+	char text[17];
+
+	text[16] = '\0';
+	//printf("Hex dump:\r\n");
+	fprintf(fp, "%p : ", src);
+	for(i=0; i<len; i++) {
+		j++;
+		fprintf(fp, "%02X ", ((volatile unsigned char *)src)[i]);
+		if(j == 8)
+			fputc(' ', fp);
+		if(j == 16) {
+			j = 0;
+			memcpy(text, &((char *)src)[i-15], 16);
+			for(k=0; k<16; k++) {
+				if((text[k] < 32) || (text[k] > 126)) {
+					text[k] = '.';
+				}
+			}
+			fprintf(fp, " |%s|\n\r", text);
+			if(i<len-1) {
+				fprintf(fp, "%p : ", src+i+1);
+			}
+		}
+	}
+	if (i % 16)
+		fprintf(fp, "\r\n");
+}
+
+void hex_dump_buff_line(FILE *fp, int addr_size, unsigned pos, char *line, unsigned len)
+{
+  unsigned i;
+
+  fprintf(fp, "%0*x", addr_size, pos);
+  for (i = 0; i < HEX_DUMP_LINE_BUFF_SIZ; i++)
+  {
+    if (!(i % 8))
+      fputc(' ', fp);
+    if (i < len)
+      fprintf(fp, " %02x", (unsigned char)line[i]);
+    else
+	  fputs("   ", fp);
+  }
+  fputs("  |", fp);
+  for (i = 0; i < HEX_DUMP_LINE_BUFF_SIZ && i < len; i++)
+  {
+    if (line[i] >= 32 && line[i] <= 126)
+      fprintf(fp, "%c", (unsigned char)line[i]);
+    else
+		fputc('.', fp);
+  }
+  fputs("|\r\n", fp);
+}

components/fileserver/CMakeLists.txt

@@ -0,0 +1,9 @@
+set(COMPONENT_ADD_INCLUDEDIRS
+        "include")
+
+set(COMPONENT_SRCDIRS
+        "src")
+
+set(COMPONENT_REQUIRES tcpip_adapter esp_http_server httpd_utils common_utils)
+
+register_component()

components/fileserver/README.txt

@@ -0,0 +1,2 @@
+File and template serving support for the http_server bundled with ESP-IDF.
+

components/fileserver/component.mk

@@ -0,0 +1,3 @@
+
+COMPONENT_SRCDIRS := src
+COMPONENT_ADD_INCLUDEDIRS := include

components/fileserver/include/fileserver/embedded_files.h

@@ -0,0 +1,51 @@
+//
+// Created on 2018/10/17 by Ondrej Hruska <ondra@ondrovo.com>
+//
+
+#ifndef FBNODE_EMBEDDED_FILES_H
+#define FBNODE_EMBEDDED_FILES_H
+
+#include <stdint.h>
+#include <esp_err.h>
+#include <stdbool.h>
+
+struct embedded_file_info {
+    const uint8_t * start;
+    const uint8_t * end;
+    const char * name;
+    const char * mime;
+};
+
+enum file_access_level {
+    /** Public = file accessed by a wildcard route */
+    FILE_ACCESS_PUBLIC = 0,
+    /** Protected = file included in a template or explicitly specified in a route */
+    FILE_ACCESS_PROTECTED = 1,
+    /** Files protected against read-out */
+    FILE_ACCESS_PRIVATE = 2,
+};
+
+extern const struct embedded_file_info EMBEDDED_FILE_LOOKUP[];
+extern const size_t EMBEDDED_FILE_LOOKUP_LEN;
+
+/**
+ * Find an embedded file by its name.
+ * 
+ * This function is weak. It crawls the EMBEDDED_FILE_LOOKUP table and checks for exact match, also
+ * testing with www_get_static_file_access_check if the access is allowed.
+ *
+ * @param name - file name
+ * @param access - access level (public - wildcard fallthrough, protected - files for the server, loaded explicitly)
+ * @param[out] file - the file struct is stored here if found, unchanged if not found.
+ * @return status code
+ */
+esp_err_t www_get_static_file(const char *name, enum file_access_level access, const struct embedded_file_info **file);
+
+/**
+ * Check file access permission (if using the default www_get_static_file implementation).
+ * 
+ * This function is weak. The default implementation returns always true.
+ */
+bool www_get_static_file_access_check(const struct embedded_file_info *file, enum file_access_level access);
+
+#endif //FBNODE_EMBEDDED_FILES_H

components/fileserver/include/fileserver/token_subs.h

@@ -0,0 +1,227 @@
+//
+// This module implements token substitution in files served by the server.
+//
+// Tokens are in the form {token}, or {escape:token}, where escape can be:
+// - h ... html escape (plain text in a html file, attribute value)
+// - j ... js escape (for use in JS strings)
+//
+// When no escape is specified, the token substitution is written verbatim into the response.
+//
+//   var foo = "{j:foo}";
+//   <input value="{h:old_value}">
+//   {generated-html-goes-here}
+//
+// Token can be made optional by adding '?' at the end (this can't be used for includes).
+// Such token then simply becomes empty string when not substituted, as opposed to being included in the page verbatim.
+//
+//   <input value="{h:old_value?}">
+//
+// token names can contain alnum, dash, period and underscore, and are case sensitive.
+//
+//
+// It is further possible to include a static file with optional key-value replacements. These serve as defaults.
+//
+//   {@_subfile.html}
+//   {@_subfile.html|key=value lalala}
+//   {@_subfile.html|key=value lalala|other=value}
+//
+// File inclusion can be nested, and the files can use replacement tokens as specified by the include statement
+//
+// Created on 2019/01/24 by Ondrej Hruska <ondra@ondrovo.com>
+//
+
+#ifndef FBNODE_TOKEN_SUBS_H
+#define FBNODE_TOKEN_SUBS_H
+
+#include "embedded_files.h"
+#include <rom/queue.h>
+#include <esp_err.h>
+#include <esp_http_server.h>
+
+/** Max length of a token buffer (must suffice for all included filenames) */
+#define MAX_TOKEN_LEN 32
+
+/** Max length of a key-value substitution when using tpl_kv_replacer;
+ * This is also used internally for in-line replacements in file imports. */
+#define TPL_KV_KEY_LEN 24
+/** Max length of a substituion in tpl_kv_replacer */
+#define TPL_KV_SUBST_LEN 64
+
+/**
+ * Escape type - argument for httpd_resp_send_chunk_escaped()
+ */
+typedef enum {
+    TPL_ESCAPE_NONE = 0,
+    TPL_ESCAPE_HTML,
+    TPL_ESCAPE_JS,
+} tpl_escape_t;
+
+enum {
+    HTOPT_NONE = 0,
+    HTOPT_NO_HEADERS = 1 << 0,
+    HTOPT_NO_CLOSE = 1 << 1,
+    HTOPT_INCLUDE = HTOPT_NO_HEADERS|HTOPT_NO_CLOSE,
+};
+
+/**
+ * Send string using a given escaping scheme
+ *
+ * @param r
+ * @param buf - buf to send
+ * @param len - buf len, or HTTPD_RESP_USE_STRLEN
+ * @param escape - escaping type
+ * @return success
+ */
+esp_err_t httpd_resp_send_chunk_escaped(httpd_req_t *r, const char *buf, ssize_t len, tpl_escape_t escape);
+
+/**
+ * Template substitution callback. Data shall be sent using httpd_resp_send_chunk_escaped().
+ *
+ * @param[in,out] context - user-defined page state data
+ * @param[in] token - replacement token
+ * @return ESP_OK if the token was substituted, ESP_ERR_NOT_FOUND if it is unknown, other errors on e.g. send failure
+ */
+typedef esp_err_t (*template_subst_t)(httpd_req_t *r, void *context, const char *token, tpl_escape_t escape);
+
+/**
+ * Send a template file as a response. The content type from the file struct will be used.
+ *
+ * Use HTOPT_INCLUDE when used to embed a file inside a template.
+ *
+ * @param r - request
+ * @param file_index - file index in EMBEDDED_FILE_LOOKUP
+ * @param replacer - substitution callback, can be NULL if only includes are to be processed
+ * @param context - arbitrary context, will be passed to the replacer function; can be NULL
+ * @param opts - flag options (HTOPT_*)
+ */
+esp_err_t httpd_send_template_file(httpd_req_t *r, int file_index, template_subst_t replacer, void *context, uint32_t opts);
+
+/**
+ * Same as httpd_send_template_file, but using an `embedded_file_info` struct.
+ */
+esp_err_t httpd_send_template_file_struct(httpd_req_t *r, const struct embedded_file_info *file, template_subst_t replacer, void *context, uint32_t opts);
+
+/**
+ * Process and send a string template.
+ * The content-type header should be set beforehand, if different from the default (text/html).
+ *
+ * Use HTOPT_INCLUDE when used to embed a file inside a template.
+ *
+ * @param r - request
+ * @param template - template string (does not have to be terminated by a null byte)
+ * @param template_len - length of the template string; -1 to use strlen()
+ * @param replacer - substitution callback, can be NULL if only includes are to be processed
+ * @param context - arbitrary context, will be passed to the replacer function; can be NULL
+ * @param opts - flag options (HTOPT_*)
+ */
+esp_err_t httpd_send_template(httpd_req_t *r, const char *template, ssize_t template_len, template_subst_t replacer, void *context, uint32_t opts);
+
+/**
+ * Send a static file. This can be used to just send a file, or to embed a static template as a token substitution.
+ *
+ * Use HTOPT_INCLUDE when used to embed a file inside a template.
+ *
+ * Note: use httpd_resp_send_chunk_escaped() or httpd_resp_send_chunk() to send a plain string.
+ *
+ * @param r - request
+ * @param file_index - file index in EMBEDDED_FILE_LOOKUP
+ * @param escape - escape option
+ * @param opts - flag options (HTOPT_*)
+ * @return
+ */
+esp_err_t httpd_send_static_file(httpd_req_t *r, int file_index, tpl_escape_t escape, uint32_t opts);
+
+/**
+ * Same as httpd_send_template_file, but using an `embedded_file_info` struct.
+ */
+esp_err_t httpd_send_static_file_struct(httpd_req_t *r, const struct embedded_file_info *file, tpl_escape_t escape, uint32_t opts);
+
+struct tpl_kv_entry {
+    char key[TPL_KV_KEY_LEN]; // copied here
+    char subst[TPL_KV_SUBST_LEN]; // copied here
+    char *subst_heap;
+    SLIST_ENTRY(tpl_kv_entry) link;
+};
+
+SLIST_HEAD(tpl_kv_list, tpl_kv_entry);
+
+/**
+ * key-value replacer that works with a dynamically allocated SLIST.
+ *
+ * @param r - request
+ * @param context - context - must be a pointer to `struct tpl_kv_list`
+ * @param token - token to replace
+ * @param escape - escape option
+ * @return OK/not found/other
+ */
+esp_err_t tpl_kv_replacer(httpd_req_t *r, void *context, const char *token, tpl_escape_t escape);
+
+/**
+ * Add a pair into the substitutions list
+ *
+ * @param head - list head
+ * @param key - key, copied
+ * @param subst - value, copied
+ * @return success (fails if malloc failed)
+ */
+esp_err_t tpl_kv_add(struct tpl_kv_list *head, const char *key, const char *subst);
+
+/**
+ * Add a heap-allocated string to the replacer.
+ *
+ * @param head - list head
+ * @param key - key, copied
+ * @param subst - value, copied
+ * @return success (fails if malloc failed)
+ */
+esp_err_t tpl_kv_add_heapstr(struct tpl_kv_list *head, const char *key, char *subst);
+
+/**
+ * Convenience function that converts an IP address to string and adds it as a substitution
+ *
+ * @param head - list head
+ * @param key - key, copied
+ * @param ip4h - host order ipv4 address
+ * @return success
+ */
+esp_err_t tpl_kv_add_ipv4str(struct tpl_kv_list *head, const char *key, uint32_t ip4h);
+
+/** add int as a substitution; key is copied */
+esp_err_t tpl_kv_add_int(struct tpl_kv_list *head, const char *key, int32_t num);
+
+/** add long as a substitution; key is copied */
+esp_err_t tpl_kv_add_long(struct tpl_kv_list *head, const char *key, int64_t num);
+
+/** add printf-formatted value; key is copied */
+esp_err_t tpl_kv_sprintf(struct tpl_kv_list *head, const char *key, const char *format, ...)
+    __attribute__((format(printf,3,4)));
+
+/**
+ * Init a substitutions list (on the stack)
+ *
+ * @return the list
+ */
+static inline struct tpl_kv_list tpl_kv_init(void)
+{
+    return (struct tpl_kv_list) {.slh_first = NULL};
+}
+
+/**
+ * Free the list (head is left alone because it was allocated on the stack)
+ * @param head
+ */
+void tpl_kv_free(struct tpl_kv_list *head);
+
+/**
+ * Send the map as an ASCII table separated by Record Separator (30) and Unit Separator (31).
+ * Content type is set to application/octet-stream.
+ *
+ * key 31 value 30
+ * key 31 value 30
+ * key 31 value
+ *
+ * @param req
+ */
+esp_err_t tpl_kv_send_as_ascii_map(httpd_req_t *req, struct tpl_kv_list *head);
+
+#endif //FBNODE_TOKEN_SUBS_H

components/fileserver/readme/README.md

@@ -0,0 +1,29 @@
+Place the `rebuild_file_tables.php` script in a `files` subfolder of the main component.
+It requires PHP 7 to run. 
+
+This is what the setup should look like
+
+```
+main/files/embed/index.html
+main/files/rebuild_file_tables.php
+main/CMakeLists.txt
+main/main.c
+```
+
+Add this to your CMakeLists.txt before `register_component`:
+
+```
+#begin staticfiles
+#end staticfiles
+```
+
+The script will update CMakeLists.txt and generate `files_enum.c` and `files_enum.h` when run.
+
+```
+main/files/files_enum.h
+main/files/files_enum.c
+```
+
+Ensure `files/files_enum.c` is included in the build.
+
+`www_get_static_file()` is implemented as weak to let you provide custom access authentication logic.

components/fileserver/readme/rebuild_file_tables.php

@@ -0,0 +1,170 @@
+#!/usr/bin/env php
+<?php
+// This script rebuilds the static files enum, extern symbols pointing to the embedded byte buffers,
+// and the look-up structs table. To add more files, simply add them in the 'files' directory.
+
+// Note that all files will be accessible by the webserver, unless you filter them in embedded_files.c.
+
+
+// List all files
+$files = scandir(__DIR__.'/embed');
+
+$files = array_filter(array_map(function ($f) {
+  if (!is_file(__DIR__.'/embed/'.$f)) return null;
+  if (preg_match('/^\.|\.kate-swp|\.bak$|~$|\.sh$/', $f)) return null;
+
+  echo "Found: $f\n";
+  return $f;
+}, $files));
+
+sort($files);
+
+$formatted = array_filter(array_map(function ($f) {
+  return "\"files/embed/$f\"";
+}, $files));
+
+$cmake = file_get_contents(__DIR__.'/../CMakeLists.txt');
+
+$cmake = preg_replace('/#begin staticfiles\n.*#end staticfiles/s', 
+  "#begin staticfiles\n".
+  "set(COMPONENT_EMBED_FILES\n        ".
+  implode("\n        ", $formatted) . ")\n".
+  "#end staticfiles", 
+  $cmake);
+
+file_put_contents(__DIR__.'/../CMakeLists.txt', $cmake);
+
+
+// Generate a list of files
+
+$num = 0;
+$enum_keys = array_map(function ($f) use(&$num) {
+  $a = preg_replace("/[^A-Z0-9_]+/", "_", strtoupper($f));
+  return 'FILE_'. $a.' = '.($num++);
+}, $files);
+
+$keylist = implode(",\n    ", $enum_keys);
+
+$struct_array = [];
+
+$externs = array_map(function ($f) use (&$struct_array) {
+  $a = preg_replace("/[^A-Z0-9_]+/", "_", strtoupper($f));
+  
+  $start = '_binary_'. strtolower($a).'_start';
+  $end = '_binary_'. strtolower($a).'_end';
+  
+  static $mimes = array(
+    'txt' => 'text/plain',
+    'htm' => 'text/html',
+    'html' => 'text/html',
+    'php' => 'text/html',
+    'css' => 'text/css',
+    'js' => 'application/javascript',
+    'json' => 'application/json',
+    'xml' => 'application/xml',
+    'swf' => 'application/x-shockwave-flash',
+    'flv' => 'video/x-flv',
+    
+    'pem' => 'application/x-pem-file',
+
+    // images
+    'png' => 'image/png',
+    'jpe' => 'image/jpeg',
+    'jpeg' => 'image/jpeg',
+    'jpg' => 'image/jpeg',
+    'gif' => 'image/gif',
+    'bmp' => 'image/bmp',
+    'ico' => 'image/vnd.microsoft.icon',
+    'tiff' => 'image/tiff',
+    'tif' => 'image/tiff',
+    'svg' => 'image/svg+xml',
+    'svgz' => 'image/svg+xml',
+
+    // archives
+    'zip' => 'application/zip',
+    'rar' => 'application/x-rar-compressed',
+    'exe' => 'application/x-msdownload',
+    'msi' => 'application/x-msdownload',
+    'cab' => 'application/vnd.ms-cab-compressed',
+
+    // audio/video
+    'mp3' => 'audio/mpeg',
+    'qt' => 'video/quicktime',
+    'mov' => 'video/quicktime',
+
+    // adobe
+    'pdf' => 'application/pdf',
+    'psd' => 'image/vnd.adobe.photoshop',
+    'ai' => 'application/postscript',
+    'eps' => 'application/postscript',
+    'ps' => 'application/postscript',
+
+    // ms office
+    'doc' => 'application/msword',
+    'rtf' => 'application/rtf',
+    'xls' => 'application/vnd.ms-excel',
+    'ppt' => 'application/vnd.ms-powerpoint',
+
+    // open office
+    'odt' => 'application/vnd.oasis.opendocument.text',
+    'ods' => 'application/vnd.oasis.opendocument.spreadsheet',
+  );
+  
+  $parts = explode('.', $f);
+  $suffix = end($parts);
+  $mime = $mimes[$suffix] ?? 'application/octet-stream';
+  
+  $len = filesize('embed/'.$f);
+  
+  $struct_array[] = "[FILE_$a] = {{$start}, {$end}, \"{$f}\", \"{$mime}\"},";
+  
+  return 
+    'extern const uint8_t '.$start.'[];'."\n".
+    'extern const uint8_t '.$end.'[];';
+}, $files);
+
+$externlist = implode("\n", $externs);
+$structlist = implode("\n    ", $struct_array);
+
+
+file_put_contents('files_enum.h', <<<FILE
+// Do not change, auto-generated by gen_staticfiles.php
+
+#ifndef _EMBEDDED_FILES_ENUM_H
+#define _EMBEDDED_FILES_ENUM_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+enum embedded_file_id {
+    $keylist,
+    FILE_MAX
+};
+
+struct embedded_file_info {
+  const uint8_t * start;
+  const uint8_t * end;
+  const char * name;
+  const char * mime;
+};
+
+$externlist
+
+extern const struct embedded_file_info EMBEDDED_FILE_LOOKUP[];
+
+#endif // _EMBEDDED_FILES_ENUM_H
+
+FILE
+);
+
+file_put_contents("files_enum.c", <<<FILE
+// Do not change, auto-generated by gen_staticfiles.php
+#include <stdint.h>
+#include "files_enum.h"
+
+const struct embedded_file_info EMBEDDED_FILE_LOOKUP[] = {
+    $structlist
+};
+
+FILE
+);

components/fileserver/src/embedded_files.c

@@ -0,0 +1,22 @@
+#include <esp_err.h>
+#include "fileserver/embedded_files.h"
+#include "string.h"
+
+esp_err_t __attribute__((weak)) 
+www_get_static_file(const char *name, enum file_access_level access, const struct embedded_file_info **file)
+{
+    // simple search by name
+    for(int i = 0; i < EMBEDDED_FILE_LOOKUP_LEN; i++) {
+        if (0 == strcmp(EMBEDDED_FILE_LOOKUP[i].name, name)) {
+            *file = &EMBEDDED_FILE_LOOKUP[i];
+            return ESP_OK;
+        }
+    }
+
+    return ESP_ERR_NOT_FOUND;
+}
+
+bool __attribute__((weak)) 
+www_get_static_file_access_check(const struct embedded_file_info *file, enum file_access_level access) {
+  return true;
+}

components/fileserver/src/token_subs.c

@@ -0,0 +1,625 @@
+//#define LOG_LOCAL_LEVEL ESP_LOG_DEBUG
+
+#include <esp_log.h>
+#include <esp_http_server.h>
+#include <rom/queue.h>
+#include <lwip/ip4_addr.h>
+#include <sys/param.h>
+#include <common_utils/utils.h>
+#include <fileserver/token_subs.h>
+
+#include "fileserver/embedded_files.h"
+#include "fileserver/token_subs.h"
+
+#define ESP_TRY(x) \
+    do {  \
+        esp_err_t try_er = (x);  \
+        if (try_er != ESP_OK) return try_er;  \
+    } while(0)
+
+static const char* TAG = "token_subs";
+
+// TODO implement buffering to avoid sending many tiny chunks when escaping
+
+/* encode for HTML. returns 0 or 1 - 1 = success */
+static esp_err_t send_html_chunk(httpd_req_t *r, const char *data, ssize_t len)
+{
+    assert(r);
+    assert(data);
+
+    int start = 0, end = 0;
+    char c;
+    if (len < 0) len = (int) strlen(data);
+    if (len==0) return ESP_OK;
+
+    for (end = 0; end < len; end++) {
+        c = data[end];
+        if (c == 0) {
+            // we found EOS
+            break; // not return - the last chunk is printed after the loop
+        }
+
+        if (c == '"' || c == '\'' || c == '<' || c == '>') {
+            if (start < end) ESP_TRY(httpd_resp_send_chunk(r, data + start, end - start));
+            start = end + 1;
+        }
+
+        if (c == '"') ESP_TRY(httpd_resp_send_chunk(r, "&#34;", 5));
+        else if (c == '\'') ESP_TRY(httpd_resp_send_chunk(r, "&#39;", 5));
+        else if (c == '<') ESP_TRY(httpd_resp_send_chunk(r, "&lt;", 4));
+        else if (c == '>') ESP_TRY(httpd_resp_send_chunk(r, "&gt;", 4));
+    }
+
+    if (start < end) ESP_TRY(httpd_resp_send_chunk(r, data + start, end - start));
+    return ESP_OK;
+}
+
+/* encode for JS. returns 0 or 1 - 1 = success */
+static esp_err_t send_js_chunk(httpd_req_t *r, const char *data, ssize_t len)
+{
+    assert(r);
+    assert(data);
+
+    int start = 0, end = 0;
+    char c;
+    if (len < 0) len = (int) strlen(data);
+    if (len==0) return ESP_OK;
+
+    for (end = 0; end < len; end++) {
+        c = data[end];
+        if (c == 0) {
+            // we found EOS
+            break; // not return - the last chunk is printed after the loop
+        }
+
+        if (c == '"' || c == '\\' || c == '/' || c == '\'' || c == '<' || c == '>' || c == '\n' || c == '\r') {
+            if (start < end) ESP_TRY(httpd_resp_send_chunk(r, data + start, end - start));
+            start = end + 1;
+        }
+
+        if (c == '"') ESP_TRY(httpd_resp_send_chunk(r, "\\\"", 2));
+        else if (c == '\'') ESP_TRY(httpd_resp_send_chunk(r, "\\'", 2));
+        else if (c == '\\') ESP_TRY(httpd_resp_send_chunk(r, "\\\\", 2));
+        else if (c == '/') ESP_TRY(httpd_resp_send_chunk(r, "\\/", 2));
+        else if (c == '<') ESP_TRY(httpd_resp_send_chunk(r, "\\u003C", 6));
+        else if (c == '>') ESP_TRY(httpd_resp_send_chunk(r, "\\u003E", 6));
+        else if (c == '\n') ESP_TRY(httpd_resp_send_chunk(r, "\\n", 2));
+        else if (c == '\r') ESP_TRY(httpd_resp_send_chunk(r, "\\r", 2));
+    }
+
+    if (start < end) ESP_TRY(httpd_resp_send_chunk(r, data + start, end - start));
+    return ESP_OK;
+}
+
+
+esp_err_t httpd_resp_send_chunk_escaped(httpd_req_t *r, const char *buf, ssize_t len, tpl_escape_t escape)
+{
+    switch (escape) {
+        default: // this enum should be exhaustive, but in case something went wrong, just print it verbatim
+
+        case TPL_ESCAPE_NONE:
+            return httpd_resp_send_chunk(r, buf, len);
+
+        case TPL_ESCAPE_HTML:
+            return send_html_chunk(r, buf, len);
+
+        case TPL_ESCAPE_JS:
+            return send_js_chunk(r, buf, len);
+    }
+}
+
+esp_err_t httpd_send_static_file(httpd_req_t *r, int file_index, tpl_escape_t escape, uint32_t opts)
+{
+    assert(file_index < EMBEDDED_FILE_LOOKUP_LEN);
+    const struct embedded_file_info *file = &EMBEDDED_FILE_LOOKUP[file_index];
+
+    return httpd_send_static_file_struct(r, file, escape, opts);
+}
+
+esp_err_t httpd_send_static_file_struct(httpd_req_t *r, const struct embedded_file_info *file, tpl_escape_t escape, uint32_t opts)
+{
+    if (0 == (opts & HTOPT_NO_HEADERS)) {
+        ESP_TRY(httpd_resp_set_type(r, file->mime));
+        ESP_TRY(httpd_resp_set_hdr(r, "Cache-Control", "max-age=86400, public, must-revalidate"));
+    }
+
+    ESP_TRY(httpd_resp_send_chunk_escaped(r, (const char *) file->start, (size_t)(file->end - file->start), escape));
+
+    if (0 == (opts & HTOPT_NO_CLOSE)) {
+        ESP_TRY(httpd_resp_send_chunk(r, NULL, 0));
+    }
+
+    return ESP_OK;
+}
+
+esp_err_t httpd_send_template_file(httpd_req_t *r,
+                                   int file_index,
+                                   template_subst_t replacer,
+                                   void *context,
+                                   uint32_t opts)
+{
+    assert(file_index < EMBEDDED_FILE_LOOKUP_LEN);
+    const struct embedded_file_info *file = &EMBEDDED_FILE_LOOKUP[file_index];
+    return httpd_send_template_file_struct(r,file,replacer,context,opts);
+}
+
+esp_err_t httpd_send_template_file_struct(httpd_req_t *r,
+                                   const struct embedded_file_info *file,
+                                   template_subst_t replacer,
+                                   void *context,
+                                   uint32_t opts)
+{
+    if (0 == (opts & HTOPT_NO_HEADERS)) {
+        ESP_TRY(httpd_resp_set_type(r, file->mime));
+        ESP_TRY(httpd_resp_set_hdr(r, "Cache-Control", "no-cache, no-store, must-revalidate"));
+    }
+
+    return httpd_send_template(r, (const char *) file->start, (size_t)(file->end - file->start), replacer, context, opts);
+}
+
+esp_err_t tpl_kv_replacer(httpd_req_t *r, void *context, const char *token, tpl_escape_t escape)
+{
+    assert(context);
+    assert(token);
+
+    struct tpl_kv_entry *entry;
+    struct tpl_kv_list *head = context;
+    SLIST_FOREACH(entry, head, link) {
+        if (0==strcmp(entry->key, token)) {
+            if (entry->subst_heap) {
+                if (entry->subst_heap[0]) {
+                    return httpd_resp_send_chunk_escaped(r, entry->subst_heap, -1, escape);
+                }
+            } else {
+                if (entry->subst[0]) {
+                    return httpd_resp_send_chunk_escaped(r, entry->subst, -1, escape);
+                }
+                return ESP_OK;
+            }
+            return ESP_OK;
+        }
+    }
+
+    return ESP_ERR_NOT_FOUND;
+}
+
+struct stacked_replacer_context {
+    template_subst_t replacer0;
+    void *context0;
+    template_subst_t replacer1;
+    void *context1;
+};
+
+esp_err_t stacked_replacer(httpd_req_t *r, void *context, const char *token, tpl_escape_t escape)
+{
+    assert(context);
+    assert(token);
+
+    struct stacked_replacer_context *combo = context;
+
+    if (ESP_OK == combo->replacer0(r, combo->context0, token, escape)) {
+        return ESP_OK;
+    }
+
+    if (ESP_OK == combo->replacer1(r, combo->context1, token, escape)) {
+        return ESP_OK;
+    }
+
+    return ESP_ERR_NOT_FOUND;
+}
+
+esp_err_t httpd_send_template(httpd_req_t *r,
+                              const char *template, ssize_t template_len,
+                              template_subst_t replacer,
+                              void *context,
+                              uint32_t opts)
+{
+    if (template_len < 0) template_len = strlen(template);
+
+    // replacer and context may be NULL
+    assert(template);
+    assert(r);
+
+    // data end
+    const char * const end = template + template_len;
+
+    // start of to-be-processed data
+    const char * pos = template;
+
+    // start position for finding opening braces, updated after a failed match to avoid infinite loop on the same bad token
+    const char * searchpos = pos;
+
+    // tokens must be copied to a buffer to allow adding the terminating null byte
+    char token_buf[MAX_TOKEN_LEN];
+
+    while (pos < end) {
+        const char * openbr = strchr(searchpos, '{');
+        if (openbr == NULL) {
+            // no more templates
+            ESP_TRY(httpd_resp_send_chunk(r, pos, (size_t) (end - pos)));
+            break;
+        }
+
+        // this brace could start a valid template. check if it seems valid...
+        const char * closebr = strchr(openbr, '}');
+        if (closebr == NULL) {
+            // there are no further closing braces, so it can't be a template
+
+            // we also know there can't be any more substitutions, because they would lack a closing } too
+            ESP_TRY(httpd_resp_send_chunk(r, pos, (size_t) (end - pos)));
+            break;
+        }
+
+        // see if the braces content looks like a token
+        const char *t = openbr + 1;
+        bool token_valid = true;
+        struct tpl_kv_list substitutions_head = tpl_kv_init();
+        struct tpl_kv_entry *new_subst_pair = NULL;
+
+        // a token can be either a name for replacement by the replacer func, or an include with static kv replacements
+        bool is_include = false;
+        bool token_is_optional = false;
+        const char *token_end = NULL; // points one char after the end of the token
+
+        // parsing the token
+        {
+            if (*t == '@') {
+                ESP_LOGD(TAG, "Parsing an Include token");
+                is_include = true;
+                t++;
+            }
+
+            enum {
+                P_NAME, P_KEY, P_VALUE
+            } state = P_NAME;
+
+            const char *kv_start = NULL;
+            while (t != closebr || state == P_VALUE) {
+                char c = *t;
+
+                if (state == P_NAME) {
+                    if (!((c >= 'a' && c <= 'z') ||
+                          (c >= 'A' && c <= 'Z') ||
+                          (c >= '0' && c <= '9') ||
+                          c == '.' || c == '_' || c == '-' || c == ':')) {
+
+                        if (!is_include && c == '?') {
+                            token_end = t;
+                            token_is_optional = true;
+                        } else {
+                            if (is_include && c == '|') {
+                                token_end = t;
+                                state = P_KEY;
+                                kv_start = t + 1;
+                                // pipe separates the include's filename and literal substitutions
+                                // we know there is a closing } somewhere, and {@....| doesn't occur normally, so let's assume it's correct
+                            }
+                            else {
+                                token_valid = false;
+                                break;
+                            }
+                        }
+                    }
+                }
+                else if (state == P_KEY) {
+                    if (!((c >= 'a' && c <= 'z') ||
+                          (c >= 'A' && c <= 'Z') ||
+                          (c >= '0' && c <= '9') ||
+                          c == '.' || c == '_' || c == '-')) {
+                        if (c == '=') {
+                            new_subst_pair = calloc(1, sizeof(struct tpl_kv_entry));
+                            const size_t klen = MIN(TPL_KV_KEY_LEN, t - kv_start);
+                            strncpy(new_subst_pair->key, kv_start, klen);
+                            new_subst_pair->key[klen] = 0;
+
+                            kv_start = t + 1;
+
+                            state = P_VALUE;
+                            // pipe separates the include's filename and literal substitutions
+                            // we know there is a closing } somewhere, and {@....| doesn't occur normally, so let's assume it's correct
+                        }
+                    }
+                }
+                else if (state == P_VALUE) {
+                    if (c == '|' || c == '}') {
+                        const size_t vlen = MIN(TPL_KV_SUBST_LEN, t - kv_start);
+                        strncpy(new_subst_pair->subst, kv_start, vlen);
+                        new_subst_pair->subst[vlen] = 0;
+
+                        // attach the kv pair to the list
+                        SLIST_INSERT_HEAD(&substitutions_head, new_subst_pair, link);
+                        ESP_LOGD(TAG, "Adding subs kv %s -> %s", new_subst_pair->key, new_subst_pair->subst);
+                        new_subst_pair = NULL;
+
+                        kv_start = t + 1; // go past the pipe
+                        state = P_KEY;
+
+                        if (t == closebr) {
+                            break; // found the ending brace, so let's quit the kv parse loop
+                        }
+                    }
+                }
+
+                t++;
+            }
+            // clean up after a messed up subs kv pairs syntax
+            if (new_subst_pair != NULL) {
+                free(new_subst_pair);
+            }
+        }
+
+        if (!token_valid) {
+            // false match, include it in the block to send before the next token
+            searchpos = openbr + 1;
+            ESP_LOGD(TAG, "Skip invalid token near %10s", openbr);
+            continue;
+        }
+
+        // now we know it looks like a substitution token
+
+        // flush data before the token
+        if (pos != openbr) ESP_TRY(httpd_resp_send_chunk(r, pos, (size_t) (openbr - pos)));
+
+        const char *token_start = openbr;
+
+        tpl_escape_t escape = TPL_ESCAPE_NONE;
+
+        // extract and terminate the token
+        size_t token_len = MIN(MAX_TOKEN_LEN-1, closebr - openbr - 1);
+        if (token_end) {
+            token_len = MIN(token_len, token_end - openbr - 1);
+        }
+
+        if (is_include) {
+            token_start += 1; // skip the @
+            token_len -= 1;
+        } else {
+            if (0 == strncmp("h:", openbr + 1, 2)) {
+                escape = TPL_ESCAPE_HTML;
+                token_start += 2;
+                token_len -= 2;
+            }
+            else if (0 == strncmp("j:", openbr + 1, 2)) {
+                escape = TPL_ESCAPE_JS;
+                token_start += 2;
+                token_len -= 2;
+            }
+        }
+
+        strncpy(token_buf, token_start+1, token_len);
+        token_buf[token_len] = 0;
+
+        ESP_LOGD(TAG, "Token: %s", token_buf);
+
+        esp_err_t rv;
+
+        if (is_include) {
+            ESP_LOGD(TAG, "Trying to include a sub-file");
+
+            const struct embedded_file_info *file = NULL;
+            rv = www_get_static_file(token_buf, FILE_ACCESS_PROTECTED, &file);
+            if (rv != ESP_OK) {
+                ESP_LOGE(TAG, "Failed to statically include \"%s\" in a template - %s", token_buf, esp_err_to_name(rv));
+                // this will cause the token to be emitted verbatim
+            } else {
+                ESP_LOGD(TAG, "Descending...");
+
+                // combine the two replacers
+                struct stacked_replacer_context combo = {
+                    .replacer0 = replacer,
+                    .context0 = context,
+                    .replacer1 = tpl_kv_replacer,
+                    .context1 = &substitutions_head
+                };
+
+                rv = httpd_send_template_file_struct(r, file, stacked_replacer, &combo, HTOPT_INCLUDE);
+                ESP_LOGD(TAG, "...back in parent");
+            }
+
+            // tear down the list
+            tpl_kv_free(&substitutions_head);
+
+            if (rv != ESP_OK) {
+                // just send it verbatim...
+                ESP_TRY(httpd_resp_send_chunk(r, openbr, (size_t) (closebr - openbr + 1)));
+            }
+        } else {
+            if (replacer) {
+                ESP_LOGD(TAG, "Running replacer for \"%s\" with escape %d", token_buf, escape);
+                rv = replacer(r, context, token_buf, escape);
+
+                if (rv != ESP_OK) {
+                    if (rv == ESP_ERR_NOT_FOUND) {
+                        ESP_LOGD(TAG, "Token rejected");
+                        // optional token becomes empty string if not replaced
+                        if (!token_is_optional) {
+                            ESP_LOGD(TAG, "Not optional, keeping verbatim");
+                            // replacer rejected the token, keep it verbatim
+                            ESP_TRY(httpd_resp_send_chunk(r, openbr, (size_t) (closebr - openbr + 1)));
+                        }
+                    }
+                    else {
+                        ESP_LOGE(TAG, "Unexpected error from replacer func: 0x%02x - %s", rv, esp_err_to_name(rv));
+                        return rv;
+                    }
+                }
+            } else {
+                ESP_LOGD(TAG, "Not replacer");
+                // no replacer, only includes - used for 'static' files
+                if (!token_is_optional) {
+                    ESP_LOGD(TAG, "Token not optional, keeping verbatim");
+                    ESP_TRY(httpd_resp_send_chunk(r, openbr, (size_t) (closebr - openbr + 1)));
+                }
+            }
+        }
+
+        searchpos = pos = closebr + 1;
+    }
+
+    if (0 == (opts & HTOPT_NO_CLOSE)) {
+        ESP_TRY(httpd_resp_send_chunk(r, NULL, 0));
+    }
+
+    return ESP_OK;
+}
+
+
+esp_err_t tpl_kv_add_int(struct tpl_kv_list *head, const char *key, int32_t num)
+{
+    char buf[12];
+    itoa(num, buf, 10);
+    return tpl_kv_add(head, key, buf);
+}
+
+esp_err_t tpl_kv_add_long(struct tpl_kv_list *head, const char *key, int64_t num)
+{
+    char buf[21];
+    sprintf(buf, "%"PRIi64, num);
+    return tpl_kv_add(head, key, buf);
+}
+
+esp_err_t tpl_kv_add_ipv4str(struct tpl_kv_list *head, const char *key, uint32_t ip4h)
+{
+    char buf[IP4ADDR_STRLEN_MAX];
+    ip4_addr_t addr;
+    addr.addr = lwip_htonl(ip4h);
+    ip4addr_ntoa_r(&addr, buf, IP4ADDR_STRLEN_MAX);
+
+    return tpl_kv_add(head, key, buf);
+}
+
+esp_err_t tpl_kv_add(struct tpl_kv_list *head, const char *key, const char *subst)
+{
+    ESP_LOGD(TAG, "kv add subs %s := %s", key, subst);
+    struct tpl_kv_entry *entry = calloc(1, sizeof(struct tpl_kv_entry));
+    if (entry == NULL) return ESP_ERR_NO_MEM;
+
+    assert(strlen(key) < TPL_KV_KEY_LEN);
+    assert(strlen(subst) < TPL_KV_SUBST_LEN);
+
+    strncpy(entry->key, key, TPL_KV_KEY_LEN);
+    entry->key[TPL_KV_KEY_LEN - 1] = 0;
+
+    strncpy(entry->subst, subst, TPL_KV_SUBST_LEN - 1);
+    entry->subst[TPL_KV_KEY_LEN - 1] = 0;
+
+    SLIST_INSERT_HEAD(head, entry, link);
+    return ESP_OK;
+}
+
+esp_err_t tpl_kv_add_heapstr(struct tpl_kv_list *head, const char *key, char *subst)
+{
+    ESP_LOGD(TAG, "kv add subs %s := (heap str)", key);
+    struct tpl_kv_entry *entry = calloc(1, sizeof(struct tpl_kv_entry));
+    if (entry == NULL) return ESP_ERR_NO_MEM;
+
+    assert(strlen(key) < TPL_KV_KEY_LEN);
+
+    strncpy(entry->key, key, TPL_KV_KEY_LEN);
+    entry->key[TPL_KV_KEY_LEN - 1] = 0;
+
+    entry->subst_heap = subst;
+
+    SLIST_INSERT_HEAD(head, entry, link);
+    return ESP_OK;
+}
+
+esp_err_t tpl_kv_sprintf(struct tpl_kv_list *head, const char *key, const char *format, ...)
+{
+    ESP_LOGD(TAG, "kv printf %s := %s", key, format);
+    struct tpl_kv_entry *entry = calloc(1, sizeof(struct tpl_kv_entry));
+    if (entry == NULL) return ESP_ERR_NO_MEM;
+
+    assert(strlen(key) < TPL_KV_KEY_LEN);
+
+    strncpy(entry->key, key, TPL_KV_KEY_LEN);
+    entry->key[TPL_KV_KEY_LEN - 1] = 0;
+
+    va_list list;
+    va_start(list, format);
+    vsnprintf(entry->subst, TPL_KV_SUBST_LEN, format, list);
+    va_end(list);
+    entry->subst[TPL_KV_KEY_LEN - 1] = 0;
+
+    SLIST_INSERT_HEAD(head, entry, link);
+    return ESP_OK;
+}
+
+void tpl_kv_free(struct tpl_kv_list *head)
+{
+    struct tpl_kv_entry *item, *next;
+    SLIST_FOREACH_SAFE(item, head, link, next) {
+        if (item->subst_heap) {
+            free(item->subst_heap);
+            item->subst_heap = NULL;
+        }
+
+        free(item);
+    }
+}
+
+esp_err_t tpl_kv_send_as_ascii_map(httpd_req_t *req, struct tpl_kv_list *head)
+{
+    httpd_resp_set_type(req, "text/plain; charset=utf-8");
+
+#define BUF_CAP 512
+    char *buf_head = malloc(BUF_CAP);
+    if (!buf_head) {
+        ESP_LOGE(TAG, "Malloc err");
+        return ESP_FAIL;
+    }
+    char *buf = buf_head;
+    size_t cap = BUF_CAP;
+    struct tpl_kv_entry *entry;
+
+    // GCC nested function
+    esp_err_t send_part() {
+        esp_err_t suc = httpd_resp_send_chunk(req, buf_head, BUF_CAP-cap);
+        buf = buf_head; // buf is assigned to buf head
+        cap = BUF_CAP;
+        if (suc != ESP_OK) {
+            ESP_LOGE(TAG, "Error sending buffer");
+            free(buf_head);
+            httpd_resp_send_chunk(req, NULL, 0);
+        }
+        return suc;
+    }
+
+    SLIST_FOREACH(entry, head, link) {
+        while(NULL == (buf = append(buf, entry->key, &cap))) ESP_TRY(send_part());
+        while(NULL == (buf = append(buf, "\x1f", &cap))) ESP_TRY(send_part());
+
+        if (entry->subst_heap) {
+            if (strlen(entry->subst_heap) >= BUF_CAP) {
+                // send what we have
+                ESP_TRY(send_part());
+                esp_err_t suc = httpd_resp_send_chunk(req, entry->subst_heap, -1);
+                if (suc != ESP_OK) {
+                    ESP_LOGE(TAG, "Error sending buffer");
+                    free(buf_head);
+                    httpd_resp_send_chunk(req, NULL, 0);
+                }
+            } else {
+                while (NULL == (buf = append(buf, entry->subst_heap, &cap))) ESP_TRY(send_part());
+            }
+        } else {
+            while(NULL == (buf = append(buf, entry->subst, &cap))) ESP_TRY(send_part());
+        }
+
+        if (entry->link.sle_next) {
+            while(NULL == (buf = append(buf, "\x1e", &cap))) ESP_TRY(send_part());
+        }
+    }
+    // send leftovers
+    if (buf != buf_head) {
+        esp_err_t suc = httpd_resp_send_chunk(req, buf_head, BUF_CAP-cap);
+        if (suc != ESP_OK) {
+            ESP_LOGE(TAG, "Error sending buffer");
+        }
+    }
+
+    // Commit
+    httpd_resp_send_chunk(req, NULL, 0);
+    free(buf_head);
+    return ESP_OK;
+}

components/httpd_utils/CMakeLists.txt

@@ -0,0 +1,9 @@
+set(COMPONENT_ADD_INCLUDEDIRS
+        "include")
+
+set(COMPONENT_SRCDIRS
+        "src")
+
+set(COMPONENT_REQUIRES tcpip_adapter esp_http_server common_utils)
+
+register_component()

components/httpd_utils/README.txt

@@ -0,0 +1,4 @@
+Functions enriching the HTTP server bundled with ESP-IDF.
+This package includes HTTP-related utilities, captive
+portal implementation, and a cookie-based session system with a
+key-value store and expirations.

components/httpd_utils/component.mk

@@ -0,0 +1,3 @@
+
+COMPONENT_SRCDIRS := src
+COMPONENT_ADD_INCLUDEDIRS := include

components/httpd_utils/include/httpd_utils/captive.h

@@ -0,0 +1,32 @@
+#ifndef HTTPD_UTILS_CAPTIVE_H
+#define HTTPD_UTILS_CAPTIVE_H
+
+#include <esp_http_server.h>
+#include <esp_err.h>
+
+/**
+ * Redirect if needed when a captive portal capture is detected
+ *
+ * @param r
+ * @return ESP_OK on redirect, ESP_ERR_NOT_FOUND if not needed, other error on failure
+ */
+esp_err_t httpd_captive_redirect(httpd_req_t *r);
+
+/**
+ * Get URL to redirect to. WEAK.
+ *
+ * @param r
+ * @param buf
+ * @param maxlen
+ * @return http(s)://foo.bar/
+ */
+esp_err_t httpd_captive_redirect_get_url(httpd_req_t *r, char *buf, size_t maxlen);
+
+/**
+ * Get captive portal domain. WEAK.
+ *
+ * @return foo.bar
+ */
+const char * httpd_captive_redirect_get_domain();
+
+#endif //HTTPD_UTILS_CAPTIVE_H

components/httpd_utils/include/httpd_utils/fd_to_ipv4.h

@@ -0,0 +1,13 @@
+#ifndef HTTPD_FDIPV4_H
+#define HTTPD_FDIPV4_H
+
+/**
+ * Get IP address for a FD
+ *
+ * @param fd
+ * @param[out] ipv4
+ * @return success
+ */
+esp_err_t fd_to_ipv4(int fd, in_addr_t *ipv4);
+
+#endif //HTTPD_FDIPV4_H

components/httpd_utils/include/httpd_utils/redirect.h

@@ -0,0 +1,16 @@
+#ifndef HTTPD_UTILS_REDIRECT_H
+#define HTTPD_UTILS_REDIRECT_H
+
+#include <esp_http_server.h>
+#include <esp_err.h>
+
+/**
+ * Redirect to other URI - sends a HTTP response from the http server
+ *
+ * @param r - request
+ * @param uri - target uri
+ * @return success
+ */
+esp_err_t httpd_redirect_to(httpd_req_t *r, const char *uri);
+
+#endif // HTTPD_UTILS_REDIRECT_H

components/httpd_utils/include/httpd_utils/session.h

@@ -0,0 +1,55 @@
+/**
+ * Session store system main include file
+ *
+ * Created on 2019/07/13.
+ */
+
+#ifndef HTTPD_UTILS_SESSION_H
+#define HTTPD_UTILS_SESSION_H
+
+#include "session_kvmap.h"
+#include "session_store.h"
+
+// Customary keys
+
+/** Session key for OK flash message */
+#define SESS_FLASH_OK "flash_ok"
+/** Session key for error flash message */
+#define SESS_FLASH_ERR "flash_err"
+/** Session key for a "logged in" flag. Value is 1 if logged in. */
+#define SESS_AUTHED "authed"
+
+// ..
+
+/**
+ * Redirect to /login form if unauthed,
+ * but also retrieve the session key-value store for further use
+ */
+#define HTTP_GET_AUTHED_SESSION(kvstore, r) do {                            \
+    kvstore = httpd_req_find_session_and((r), SESS_GET_DATA);               \
+    if (NULL == kvstore || NULL == sess_kv_map_get(kvstore, SESS_AUTHED)) { \
+        return httpd_redirect_to((r), "/login");                            \
+    }                                                                       \
+} while(0)
+
+/**
+ * Start or resume a session without checking for authed status.
+ * When started, the session cookie is added to the response immediately.
+ *
+ * @param[out] kvstore - a place to store the allocated or retrieved session kvmap
+ * @param[in] r - request
+ * @return success
+ */
+esp_err_t HTTP_GET_SESSION(sess_kv_map_t **kvstore, httpd_req_t *r);
+
+/**
+ * Redirect to the login form if unauthed.
+ * This is the same as `HTTP_GET_AUTHED_SESSION`, except the kvstore variable is
+ * not needed in the uri handler calling this, so it is declared internally.
+ */
+#define HTTP_REDIRECT_IF_UNAUTHED(r) do {                             \
+    sess_kv_map_t *_kvstore;                                          \
+    HTTP_GET_AUTHED_SESSION(_kvstore, r);                             \
+} while(0)
+
+#endif // HTTPD_UTILS_SESSION_H

components/httpd_utils/include/httpd_utils/session_kvmap.h

@@ -0,0 +1,77 @@
+/**
+ * Simple key-value map for session data storage.
+ * Takes care of dynamic allocation and cleanup.
+ * 
+ * Created on 2019/01/28.
+ */
+
+#ifndef SESSION_KVMAP_H
+#define SESSION_KVMAP_H
+
+/**
+ * Prototype for a free() func to clean up session-held objects
+ */
+typedef void (*sess_kv_free_func_t)(void *obj);
+
+typedef struct sess_kv_map sess_kv_map_t;
+
+#define SESS_KVMAP_KEY_LEN 16
+
+/**
+ * Allocate a new session key-value store
+ *
+ * @return the store, NULL on error
+ */
+sess_kv_map_t *sess_kv_map_alloc(void);
+
+/**
+ * Free the session kv store.
+ *
+ * @param head - store head
+ */
+void sess_kv_map_free(void *head);
+
+/**
+ * Get a value from the session kv store.
+ *
+ * @param head - store head
+ * @param key - key to get a value for
+ * @return the value, or NULL if not found
+ */
+void *sess_kv_map_get(sess_kv_map_t *head, const char *key);
+
+/**
+ * Get and remove a value from the session store.
+ *
+ * The free function is not called in this case and the recipient is
+ * responsible for cleaning it up correctly.
+ *
+ * @param head - store head
+ * @param key - key to get a value for
+ * @return the value, or NULL if not found
+ */
+void * sess_kv_map_take(sess_kv_map_t *head, const char *key);
+
+/**
+ * Remove an entry from the session by its key name.
+ * The slot is not free'd yet, but is made available for reuse.
+ *
+ * @param head - store head
+ * @param key - key to remove
+ * @return success
+ */
+esp_err_t sess_kv_map_remove(sess_kv_map_t *head, const char *key);
+
+/**
+ * Set a key value. If there is an old value stored, it will be freed by its free function and replaced by the new one.
+ * Otherwise a new slot is allocated for it, or a previously released one is reused.
+ *
+ * @param head - store head
+ * @param key - key to assign to
+ * @param value - new value
+ * @param free_fn - value free func
+ * @return success
+ */
+esp_err_t sess_kv_map_set(sess_kv_map_t *head, const char *key, void *value, sess_kv_free_func_t free_fn);
+
+#endif //SESSION_KVMAP_H

components/httpd_utils/include/httpd_utils/session_store.h

@@ -0,0 +1,100 @@
+/**
+ * Cookie-based session store
+ */
+
+#ifndef SESSION_STORE_H
+#define SESSION_STORE_H
+
+#include "esp_http_server.h"
+
+#define SESSION_EXPIRY_TIME_S 60*30
+#define SESSION_COOKIE_NAME "SESSID"
+
+/** function that frees a session data object */
+typedef void (*sess_data_free_fn_t)(void *);
+
+enum session_find_action {
+    SESS_DROP, SESS_GET_DATA
+};
+
+/**
+ * Find session and either get data, or drop it.
+ *
+ * @param cookie
+ * @param action
+ * @return
+ */
+void *session_find_and(const char *cookie, enum session_find_action action);
+
+/**
+ * Initialize the session store.
+ * Safely empty it if initialized
+ */
+void session_store_init(void);
+
+// placeholder for when no data is stored
+#define SESSION_DUMMY ((void *) 1)
+
+/**
+ * Create a new session. Data must not be NULL, because it wouldn't be possible
+ * to distinguish between NULL value and session not found in return values.
+ * It can be e.g. 1 if no data storage is needed.
+ *
+ * @param data - data object to attach to the session
+ * @param free_fn - function that disposes of the data when the session expires
+ * @return NULL on error, or the new session ID. This is a live pointer into the session structure,
+ *         must be copied if stored, as it can become invalid at any time
+ */
+const char *session_new(void *data, sess_data_free_fn_t free_fn);
+
+/**
+ * Find a session by it's ID (from a cookie)
+ *
+ * @param cookie - session ID string
+ * @return session data (void*), or NULL
+ */
+void *session_find(const char *cookie);
+
+/**
+ * Loop through all sessions and drop these that expired.
+ */
+void session_drop_expired(void);
+
+/**
+ * Drop a session by its ID. Does nothing if not found.
+ *
+ * @param cookie - session ID string
+ */
+void session_drop(const char *cookie);
+
+/**
+ * Parse the Cookie header from a request, and do something with the corresponding session.
+ *
+ * To also delete the cookie, use req_delete_session_cookie(r)
+ *
+ * @param r - request
+ * @param action - what to do with the session
+ * @return session data, NULL if removed or not found
+ */
+void *httpd_req_find_session_and(httpd_req_t *r, enum session_find_action action);
+
+/**
+ * Add a header that deletes the session cookie
+ *
+ * @param r - request
+ */
+void httpd_resp_delete_session_cookie(httpd_req_t *r);
+
+/**
+ * Add a header that sets the session cookie.
+ *
+ * This must be called after creating a session (e.g. user logged in) to make it persistent.
+ *
+ * @attention NOT RE-ENTRANT, CAN'T BE USED AGAIN UNTIL THE REQUEST IT WAS CALLED FOR IS DISPATCHED.
+ *
+ * @param r - request
+ * @param cookie - cookie ID
+ */
+void httpd_resp_set_session_cookie(httpd_req_t *r, const char *cookie);
+
+#endif //SESSION_STORE_H

components/httpd_utils/src/captive.c

@@ -0,0 +1,106 @@
+#include <esp_wifi_types.h>
+#include <esp_wifi.h>
+#include <esp_log.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+#include <sys/param.h>
+
+#include "httpd_utils/captive.h"
+#include "httpd_utils/fd_to_ipv4.h"
+#include "httpd_utils/redirect.h"
+#include <common_utils/utils.h>
+
+static const char *TAG="captive";
+
+const char * __attribute__((weak))
+httpd_captive_redirect_get_domain(void)
+{
+    return "fb_node.captive";
+}
+
+esp_err_t __attribute__((weak))
+httpd_captive_redirect_get_url(httpd_req_t *r, char *buf, size_t maxlen)
+{
+    buf = append(buf, "http://", &maxlen);
+    buf = append(buf, httpd_captive_redirect_get_domain(), &maxlen);
+    append(buf, "/", &maxlen);
+
+    return ESP_OK;
+}
+
+esp_err_t httpd_captive_redirect(httpd_req_t *r)
+{
+    // must be static to survive being used in the redirect header
+    static char s_buf[64];
+
+    wifi_mode_t mode = 0;
+    esp_wifi_get_mode(&mode);
+
+    // Check if we have an softap interface. No point checking IPs and hostnames if the client can't be on AP.
+    if (mode == WIFI_MODE_STA || mode == WIFI_MODE_NULL) {
+        goto no_redirect;
+    }
+
+    int fd = httpd_req_to_sockfd(r);
+
+    tcpip_adapter_ip_info_t apip;
+    tcpip_adapter_get_ip_info(TCPIP_ADAPTER_IF_AP, &apip);
+
+    u32_t client_addr;
+    if(ESP_OK != fd_to_ipv4(fd, &client_addr)) {
+        return ESP_FAIL;
+    }
+
+    ESP_LOGD(TAG, "[captive] Client addr = 0x%08x, ap addr 0x%08x, ap nmask 0x%08x",
+             client_addr,
+             apip.ip.addr,
+             apip.netmask.addr
+    );
+
+    // Check if client IP looks like from our AP dhcps
+    if ((client_addr & apip.netmask.addr) != (apip.ip.addr & apip.netmask.addr)) {
+        ESP_LOGD(TAG, "[captive] Client not in AP IP range");
+        goto no_redirect;
+    }
+
+    // Get requested hostname from the header
+    esp_err_t rv = httpd_req_get_hdr_value_str(r, "Host", s_buf, 64);
+    if (rv != ESP_OK) {
+        ESP_LOGW(TAG, "[captive] No host in request?");
+        goto no_redirect;
+    }
+
+    ESP_LOGD(TAG, "[captive] Candidate for redirect: %s%s", s_buf, r->uri);
+
+    // Never redirect if host is an IP
+    if (strlen(s_buf)>7) {
+        bool isIP = 1;
+        for (int x = 0; x < strlen(s_buf); x++) {
+            if (s_buf[x] != '.' && (s_buf[x] < '0' || s_buf[x] > '9')) {
+                isIP = 0;
+                break;
+            }
+        }
+
+        if (isIP) {
+            ESP_LOGD(TAG, "[captive] Access via IP, no redirect needed");
+            goto no_redirect;
+        }
+    }
+
+    // Redirect if host differs
+    // - this can be e.g. connectivitycheck.gstatic.com or the equivalent for ios
+
+    if (0 != strcmp(s_buf, httpd_captive_redirect_get_domain())) {
+        ESP_LOGD(TAG, "[captive] Host differs, redirecting...");
+
+        httpd_captive_redirect_get_url(r, s_buf, 64);
+        return httpd_redirect_to(r, s_buf);
+    } else {
+        ESP_LOGD(TAG, "[captive] Host is OK");
+        goto no_redirect;
+    }
+
+    no_redirect:
+    return ESP_ERR_NOT_FOUND;
+}

components/httpd_utils/src/fd_to_ipv4.c

@@ -0,0 +1,42 @@
+#include <esp_wifi_types.h>
+#include <esp_wifi.h>
+#include <esp_log.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+
+#include "httpd_utils/fd_to_ipv4.h"
+
+static const char *TAG = "fd2ipv4";
+
+/**
+ * Get IP address for a FD
+ *
+ * @param fd
+ * @param[out] ipv4
+ * @return success
+ */
+esp_err_t fd_to_ipv4(int fd, in_addr_t *ipv4)
+{
+    struct sockaddr_in6 addr;
+    size_t len = sizeof(addr);
+    int rv = getpeername(fd, (struct sockaddr *) &addr, &len);
+    if (rv != 0) {
+        ESP_LOGE(TAG, "Failed to get IP addr for fd %d", fd);
+        return ESP_FAIL;
+    }
+
+    uint32_t client_addr = 0;
+    if (addr.sin6_family == AF_INET6) {
+        // this would fail in a real ipv6 network
+        // with ipv4 the addr is simply in the last ipv6 byte
+        struct sockaddr_in6 *s = &addr;
+        client_addr = s->sin6_addr.un.u32_addr[3];
+    }
+    else {
+        struct sockaddr_in *s = (struct sockaddr_in *) &addr;
+        client_addr = s->sin_addr.s_addr;
+    }
+
+    *ipv4 = client_addr;
+    return ESP_OK;
+}

components/httpd_utils/src/redirect.c

@@ -0,0 +1,20 @@
+#include <esp_wifi_types.h>
+#include <esp_wifi.h>
+#include <esp_log.h>
+#include <fcntl.h>
+#include <sys/socket.h>
+
+#include "httpd_utils/redirect.h"
+
+static const char *TAG="redirect";
+
+esp_err_t httpd_redirect_to(httpd_req_t *r, const char *uri)
+{
+    ESP_LOGD(TAG, "Redirect to %s", uri);
+
+    httpd_resp_set_hdr(r, "Location", uri);
+    httpd_resp_set_status(r, "303 See Other");
+    httpd_resp_set_type(r, HTTPD_TYPE_TEXT);
+    const char *msg = "Redirect";
+    return httpd_resp_send(r, msg, -1);
+}

components/httpd_utils/src/session_kvmap.c

@@ -0,0 +1,181 @@
+//#define LOG_LOCAL_LEVEL ESP_LOG_DEBUG
+
+#include <rom/queue.h>
+#include <malloc.h>
+#include <assert.h>
+#include <esp_log.h>
+#include <esp_err.h>
+#include <string.h>
+#include "httpd_utils/session_kvmap.h"
+
+static const char *TAG = "sess_kvmap";
+
+// this struct is opaque, a stub like this is sufficient for the head pointer.
+struct sess_kv_entry;
+
+/** Session head structure, dynamically allocated */
+SLIST_HEAD(sess_kv_map, sess_kv_entry);
+
+struct sess_kv_entry {
+    SLIST_ENTRY(sess_kv_entry) link;
+    char key[SESS_KVMAP_KEY_LEN];
+    void *value;
+    sess_kv_free_func_t free_fn;
+};
+
+struct sess_kv_map *sess_kv_map_alloc(void)
+{
+    ESP_LOGD(TAG, "kv store alloc");
+    struct sess_kv_map *map = malloc(sizeof(struct sess_kv_map));
+    assert(map);
+    SLIST_INIT(map);
+    return map;
+}
+
+void sess_kv_map_free(void *head_v)
+{
+    struct sess_kv_map* head = head_v;
+
+    ESP_LOGD(TAG, "kv store free");
+    assert(head);
+    struct sess_kv_entry *item, *tmp;
+    SLIST_FOREACH_SAFE(item, head, link, tmp) {
+        if (item->free_fn) {
+            item->free_fn(item->value);
+            free(item);
+        }
+    }
+    free(head);
+}
+
+
+void * sess_kv_map_get(struct sess_kv_map *head, const char *key)
+{
+    assert(head);
+    assert(key);
+    ESP_LOGD(TAG, "kv store get %s", key);
+
+    struct sess_kv_entry *item;
+    SLIST_FOREACH(item, head, link) {
+        if (0==strcmp(item->key, key)) {
+            ESP_LOGD(TAG, "got ok");
+            return item->value;
+        }
+    }
+
+    ESP_LOGD(TAG, "not found in store");
+    return NULL;
+}
+
+void * sess_kv_map_take(struct sess_kv_map *head, const char *key)
+{
+    assert(head);
+    assert(key);
+    ESP_LOGD(TAG, "kv store take %s", key);
+
+    struct sess_kv_entry *item;
+    SLIST_FOREACH(item, head, link) {
+        if (0==strcmp(item->key, key)) {
+            item->key[0] = 0;
+            item->free_fn = NULL;
+            ESP_LOGD(TAG, "taken ok");
+            return item->value;
+        }
+    }
+
+    ESP_LOGD(TAG, "not found in store");
+    return NULL;
+}
+
+esp_err_t sess_kv_map_remove(struct sess_kv_map *head, const char *key)
+{
+    assert(head);
+    assert(key);
+    ESP_LOGD(TAG, "kv store remove %s", key);
+
+    struct sess_kv_entry *item;
+    SLIST_FOREACH(item, head, link) {
+        if (0==strcmp(item->key, key)) {
+            if (item->free_fn) {
+                item->free_fn(item->value);
+            }
+            item->key[0] = 0;
+            item->value = NULL;
+            item->free_fn = NULL;
+            return ESP_OK;
+        }
+    }
+
+    ESP_LOGD(TAG, "couldn't remove, not found: %s", key);
+    return ESP_ERR_NOT_FOUND;
+}
+
+
+esp_err_t sess_kv_map_set(struct sess_kv_map *head, const char *key, void *value, sess_kv_free_func_t free_fn)
+{
+    assert(head);
+    assert(key);
+    ESP_LOGD(TAG, "kv set value for key %s", key);
+
+    size_t key_len = strlen(key);
+    if (key_len > SESS_KVMAP_KEY_LEN-1) {
+        ESP_LOGE(TAG, "Key too long: %s", key);
+        // discard illegal key
+        return ESP_FAIL;
+    }
+
+    if (key_len == 0) {
+        ESP_LOGE(TAG, "Key too short: \"%s\"", key);
+        // discard illegal key
+        return ESP_FAIL;
+    }
+
+    struct sess_kv_entry *item = NULL;
+    struct sess_kv_entry *empty_item = NULL; // found item with no content
+    SLIST_FOREACH(item, head, link) {
+        ESP_LOGD(TAG, "test item with key %s, ptr %p > %p", item->key, item, item->link.sle_next);
+        if (0 == item->key[0]) {
+            ESP_LOGD(TAG, "found an empty slot");
+            empty_item = item;
+        }
+        else if (0==strcmp(item->key, key)) {
+            ESP_LOGD(TAG, "old value replaced");
+            if (item->free_fn) {
+                item->free_fn(item->value);
+            }
+            item->value = value;
+            item->free_fn = free_fn;
+            return ESP_OK;
+        } else {
+            ESP_LOGD(TAG, "skip this one");
+        }
+    }
+
+    struct sess_kv_entry *new_item = NULL;
+
+    // insert new or reuse an empty item
+    if (empty_item) {
+        new_item = empty_item;
+        ESP_LOGD(TAG, "empty item reused (%p)", new_item);
+    } else {
+        ESP_LOGD(TAG, "alloc new item");
+        // key not found, add a new entry.
+        new_item = malloc(sizeof(struct sess_kv_entry));
+        if (!new_item) {
+            ESP_LOGE(TAG, "New entry alloc failed");
+            return ESP_ERR_NO_MEM;
+        }
+    }
+
+    strcpy(new_item->key, key);
+    new_item->free_fn = free_fn;
+    new_item->value = value;
+
+    if (!empty_item) {
+        ESP_LOGD(TAG, "insert new item into list");
+        // this item was malloc'd
+        SLIST_INSERT_HEAD(head, new_item, link);
+    }
+
+    return ESP_OK;
+}

components/httpd_utils/src/session_store.c

@@ -0,0 +1,220 @@
+//#define LOG_LOCAL_LEVEL ESP_LOG_DEBUG
+
+#include <malloc.h>
+#include <esp_log.h>
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+#include <esp_http_server.h>
+#include <rom/queue.h>
+
+#include "httpd_utils/session_store.h"
+
+// TODO add a limit on simultaneously open sessions (can cause memory exhaustion DoS)
+
+#define COOKIE_LEN 32
+static const char *TAG = "session";
+
+struct session {
+    char cookie[COOKIE_LEN + 1];
+    void *data;
+    TickType_t last_activity_time;
+    LIST_ENTRY(session) link;
+    sess_data_free_fn_t free_fn;
+};
+
+static LIST_HEAD(sessions_, session) s_store;
+
+static SemaphoreHandle_t sess_store_lock = NULL;
+static bool sess_store_inited = false;
+
+
+void session_store_init(void)
+{
+    if (sess_store_inited) {
+        xSemaphoreTake(sess_store_lock, portMAX_DELAY);
+        {
+            struct session *it, *tit;
+            LIST_FOREACH_SAFE(it, &s_store, link, tit) {
+                ESP_LOGW(TAG, "Session cookie expired: \"%s\"", it->cookie);
+                if (it->free_fn) it->free_fn(it->data);
+                // no relink, we dont care if the list breaks after this - we're removing all of it
+                free(it);
+            }
+        }
+        LIST_INIT(&s_store);
+        xSemaphoreGive(sess_store_lock);
+    } else {
+        LIST_INIT(&s_store);
+        sess_store_lock = xSemaphoreCreateMutex();
+        sess_store_inited = true;
+    }
+}
+
+/**
+ * Fill buffer with base64 symbols. Does not add a trailing null byte
+ *
+ * @param buf
+ * @param len
+ */
+static void esp_fill_random_alnum(char *buf, size_t len)
+{
+#define alphabet_len 64
+    static const char alphabet[alphabet_len] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789+/";
+
+    unsigned int seed = xTaskGetTickCount();
+
+    assert(buf != NULL);
+    for (int i = 0; i < len; i++) {
+        int index = rand_r(&seed) % alphabet_len;
+        *buf++ = (uint8_t) alphabet[index];
+    }
+}
+
+const char *session_new(void *data, sess_data_free_fn_t free_fn)
+{
+    assert(data != NULL);
+
+    struct session *item = malloc(sizeof(struct session));
+    if (item == NULL) return NULL;
+
+    item->data = data;
+    item->free_fn = free_fn;
+    esp_fill_random_alnum(item->cookie, COOKIE_LEN);
+    item->cookie[COOKIE_LEN] = 0; // add the terminator
+
+    xSemaphoreTake(sess_store_lock, portMAX_DELAY);
+    {
+        item->last_activity_time = xTaskGetTickCount();
+
+        LIST_INSERT_HEAD(&s_store, item, link);
+    }
+    xSemaphoreGive(sess_store_lock);
+
+    ESP_LOGD(TAG, "New HTTP session: %s", item->cookie);
+
+    return item->cookie;
+}
+
+void *session_find_and(const char *cookie, enum session_find_action action)
+{
+    // no point in searching if the length is wrong
+    if (strlen(cookie) != COOKIE_LEN) {
+        ESP_LOGW(TAG, "Wrong session cookie length: \"%s\"", cookie);
+        return NULL;
+    }
+
+    struct session *it = NULL;
+
+    bool found = false;
+    xSemaphoreTake(sess_store_lock, portMAX_DELAY);
+    {
+        LIST_FOREACH(it, &s_store, link) {
+            if (0==strcmp(it->cookie, cookie)) {
+                ESP_LOGD(TAG, "Session cookie matched: \"%s\"", cookie);
+
+                it->last_activity_time = xTaskGetTickCount();
+                found = true;
+                break;
+            }
+        }
+        if (found && action == SESS_DROP) {
+            if (it->free_fn) it->free_fn(it->data);
+            LIST_REMOVE(it, link);
+            free(it);
+            ESP_LOGD(TAG, "Dropped session: \"%s\"", cookie);
+        }
+    }
+    xSemaphoreGive(sess_store_lock);
+    if (found) {
+        if (action == SESS_DROP) {
+            // it was dropped inside the guarded block
+            // the return value is not used with DROP
+            return NULL;
+        }
+        else if(action == SESS_GET_DATA) {
+            return it->data;
+        }
+    }
+
+    ESP_LOGW(TAG, "Session cookie not found: \"%s\"", cookie);
+    return NULL;
+}
+
+void *session_find(const char *cookie)
+{
+    return session_find_and(cookie, SESS_GET_DATA);
+}
+
+void session_drop(const char *cookie)
+{
+    session_find_and(cookie, SESS_DROP);
+}
+
+void session_drop_expired(void)
+{
+    struct session *it;
+    struct session *tit;
+
+    xSemaphoreTake(sess_store_lock, portMAX_DELAY);
+    {
+        TickType_t now = xTaskGetTickCount();
+
+        LIST_FOREACH_SAFE(it, &s_store, link, tit) {
+            TickType_t elapsed = now - it->last_activity_time;
+            if (elapsed > pdMS_TO_TICKS(SESSION_EXPIRY_TIME_S*1000)) {
+                ESP_LOGD(TAG, "Session cookie expired: \"%s\"", it->cookie);
+                if (it->free_fn) it->free_fn(it->data);
+                LIST_REMOVE(it, link);
+                free(it);
+            }
+        }
+    }
+    xSemaphoreGive(sess_store_lock);
+}
+
+
+void *httpd_req_find_session_and(httpd_req_t *r, enum session_find_action action)
+{
+    // this could be called periodically, but it's sufficient to run it at each request
+    // it won't slow anything down unless there are hundreds of sessions
+    session_drop_expired();
+
+    static char buf[256];
+    esp_err_t rv = httpd_req_get_hdr_value_str(r, "Cookie", buf, 256);
+    if (rv == ESP_OK || rv == ESP_ERR_HTTPD_RESULT_TRUNC) {
+        ESP_LOGD(TAG, "Cookie header: %s", buf);
+
+        // probably OK, see if we have a cookie
+        char *start = strstr(buf, SESSION_COOKIE_NAME"=");
+        if (start != 0) {
+            start += strlen(SESSION_COOKIE_NAME"=");
+            char *end = strchr(start, ';');
+            if (end != NULL) *end = 0;
+
+            ESP_LOGD(TAG, "Cookie is: %s", start);
+            return session_find_and(start, action);
+        }
+    } else {
+        ESP_LOGD(TAG, "No cookie.");
+    }
+
+    return NULL;
+}
+
+void httpd_resp_delete_session_cookie(httpd_req_t *r)
+{
+    httpd_resp_set_hdr(r, "Set-Cookie", SESSION_COOKIE_NAME"=");
+}
+
+
+// Static because the value is passed and stored by reference, so it wouldn't live long enough if it was on stack,
+// and there also isn't any hook for freeing it if we used malloc(). This is an SDK bug.
+static char cookie_hdr_buf[COOKIE_LEN + 10];
+
+// !!! this must not be called concurrently from a different thread.
+// That is no problem so long as the server stays single-threaded
+void httpd_resp_set_session_cookie(httpd_req_t *r, const char *cookie)
+{
+    snprintf(cookie_hdr_buf, COOKIE_LEN + 10, "SESSID=%s", cookie);
+    httpd_resp_set_hdr(r, "Set-Cookie", cookie_hdr_buf);
+}

components/httpd_utils/src/session_utils.c

@@ -0,0 +1,41 @@
+/**
+ * TODO file description
+ * 
+ * Created on 2019/07/13.
+ */
+
+#ifndef SESSION_UTILS_C_H
+#define SESSION_UTILS_C_H
+
+#include <esp_err.h>
+#include <esp_http_server.h>
+#include "httpd_utils/session_kvmap.h"
+#include "httpd_utils/session_store.h"
+
+/**
+ * Start or resume a session.
+ */
+esp_err_t HTTP_GET_SESSION(sess_kv_map_t **ppkvstore, httpd_req_t *r)
+{
+    sess_kv_map_t *kvstore;
+    kvstore = httpd_req_find_session_and((r), SESS_GET_DATA);
+    if (NULL == kvstore) {
+        kvstore = sess_kv_map_alloc();
+        if (!kvstore) return ESP_ERR_NO_MEM;
+
+        const char *cookie = session_new(kvstore, sess_kv_map_free);
+        if (cookie == NULL) {
+            // session alloc failed
+            sess_kv_map_free(kvstore);
+            *ppkvstore = NULL;
+            return ESP_ERR_NO_MEM;
+        }
+        httpd_resp_set_session_cookie(r, cookie);
+    }
+
+    *ppkvstore = kvstore;
+    return ESP_OK;
+}
+
+
+#endif //SESSION_UTILS_C_H

main/CMakeLists.txt

@@ -1,13 +1,35 @@
 set(COMPONENT_SRCS
         "app_main.c"
-        "nokia.c"
         "knob.c"
-        "gui.c"
+        "liquid/gui.c"
         "analog.c"
         "liquid/liquid.c"
-        "liquid/scene_root.c"
+        "scenes/scene_root.c"
-        "liquid/scene_car.c"
+        "scenes/scene_bootanim.c"
+        "scenes/scene_menu.c"
+        "scenes/scene_number.c"
+        "scenes/scene_string.c"
+        "scenes/scene_manual_menu.c"
+        "scenes/scene_popup_menu.c"
+        "scenes/scene_popup_test.c"
+        "graphics/nokia.c"
+        "graphics/utf8.c"
+        "graphics/font.c"
+        "graphics/drawing.c"
+        "graphics/bitmaps.c"
+        "web/websrv.c"
+        "files/files_enum.c"
+        "utils.c"
+        "arduinopid.c"
+        "firehazard.c"
 )
-set(COMPONENT_ADD_INCLUDEDIRS "liquid")
+set(COMPONENT_ADD_INCLUDEDIRS "." "liquid" "graphics")
+
+#begin staticfiles
+# generated by rebuild_file_tables
+set(COMPONENT_EMBED_FILES
+        "files/embed/favicon.ico"
+        "files/embed/index.html")
+#end staticfiles
 
 register_component()

main/analog.c

@@ -6,6 +6,7 @@
 #include "driver/gpio.h"
 #include "driver/adc.h"
 #include "esp_adc_cal.h"
+#include "firehazard.h"
 
 static esp_adc_cal_characteristics_t *adc_chars;
 
@@ -16,12 +17,16 @@ static float measurement_celsius;
 static const adc_atten_t atten = ADC_ATTEN_DB_0;
 static const adc_unit_t unit = ADC_UNIT_1;
 
+float reg_meas_history[REG_HISTORY_LEN] = {};
+float reg_tset_history[REG_HISTORY_LEN] = {};
+uint32_t history_counter = 0;
+
 static void analog_service(void *arg);
 
 static TaskHandle_t hAnalog;
 
-#define DEFAULT_VREF 1100
+#define DEFAULT_VREF 1095
-#define NO_OF_SAMPLES 64
+#define NO_OF_SAMPLES 128
 
 void analog_init() {
     printf("Analog init\n");
@@ -35,6 +40,32 @@ void analog_init() {
     assert (rv == pdPASS);
 }
 
+#define TSENSE_LOOKUP_LEN 81
+#define TSENSE_T_STEP 5
+#define TSENSE_T_MIN 0
+#define TSENSE_T_MAX 400
+static const float TSENSE_LOOKUP[TSENSE_LOOKUP_LEN] = {
+    // 4k7
+    //0.067859346082665f, 0.069156572911158f, 0.070450833857595f, 0.07174213479836f, 0.073030481589859f, 0.074315880068592f, 0.075598336051229f, 0.076877855334685f, 0.078154443696192f, 0.079428106893372f, 0.080698850664312f, 0.081966680727637f, 0.083231602782579f, 0.084493622509052f, 0.085752745567722f, 0.087008977600079f, 0.088262324228509f, 0.089512791056363f, 0.090760383668026f, 0.092005107628991f, 0.093246968485926f, 0.094485971766743f, 0.095722122980667f, 0.096955427618307f, 0.098185891151722f, 0.099413519034488f, 0.10063831670177f, 0.101860289570385f, 0.10307944303887f, 0.10429578248755f, 0.105509313278605f, 0.106720040756132f, 0.107927970246218f, 0.109133107056997f, 0.110335456478721f, 0.111535023783824f, 0.112731814226983f, 0.113925833045189f, 0.115117085457804f, 0.116305576666627f, 0.117491311855962f, 0.118674296192672f, 0.119854534826251f, 0.12103203288888f, 0.122206795495492f, 0.123378827743833f, 0.124548134714525f, 0.125714721471126f, 0.12687859306019f, 0.128039754511331f, 0.129198210837281f, 0.13035396703395f, 0.131507028080486f, 0.132657398939339f, 0.133805084556313f, 0.134950089860629f, 0.136092419764986f, 0.137232079165615f, 0.138369072942339f, 0.139503405958634f, 0.14063508306168f, 0.141764109082427f, 0.142890488835645f, 0.144014227119983f, 0.145135328718029f, 0.146253798396361f, 0.147369640905609f, 0.148482860980504f, 0.14959346333994f, 0.150701452687026f, 0.151806833709142f, 0.152909611077994f, 0.154009789449667f, 0.155107373464683f, 0.156202367748052f, 0.157294776909324f, 0.15838460554265f, 0.159471858226827f, 0.160556539525357f, 0.161638653986497f, 0.162718206143312f
+    // 2k7
+    //0.118961788031723f,0.121199278149888f,0.123430305551104f,0.125654890818048f,0.12787305443543f,0.130084816790549f,0.132290198173841f,0.134489218779432f,0.13668189870568f,0.138868257955715f,0.141048316437981f,0.143222093966762f,0.145389610262718f,0.147550884953408f,0.149705937573814f,0.151854787566858f,0.153997454283918f,0.156133956985341f,0.158264314840951f,0.160388546930552f,0.162506672244433f,0.164618709683859f,0.166724678061576f,0.168824596102292f,0.170918482443171f,0.173006355634316f,0.17508823413925f,0.177164136335394f,0.179234080514542f,0.181298084883333f,0.183356167563718f,0.185408346593427f,0.187454639926429f,0.189495065433395f,0.191529640902147f,0.19355838403812f,0.195581312464802f,0.197598443724189f,0.199609795277224f,0.20161538450424f,0.203615228705396f,0.205609345101115f,0.207597750832512f,0.209580462961826f,0.211557498472848f,0.213528874271338f,0.215494607185455f,0.217454713966165f,0.219409211287665f,0.221358115747788f,0.223301443868418f,0.225239212095895f,0.227171436801418f,0.229098134281449f,0.231019320758111f,0.232935012379582f,0.234845225220494f,0.236749975282318f,0.238649278493758f,0.240543150711133f,0.242431607718764f,0.24431466522935f,0.246192338884353f,0.248064644254368f,0.249931596839502f,0.25179321206974f,0.253649505305317f,0.255500491837083f,0.257346186886869f,0.259186605607846f,0.261021763084885f,0.262851674334914f,0.264676354307276f,0.266495817884073f,0.268310079880525f,0.270119155045314f,0.271923058060928f,0.273721803544007f,0.275515406045682f,0.277303880051916f,0.27908723998384f
+    0.118709444844989f,0.120942188771995f,0.123168483690844f,0.125388350140555f,0.127601808562385f,0.129808879300387f,0.132009582601957f,0.134203938618385f,0.136391967405395f,0.138573688923688f,0.140749123039476f,0.142918289525014f,0.145081208059131f,0.14723789822775f,0.149388379524415f,0.151532671350807f,0.153670793017255f,0.155802763743251f,0.157928602657955f,0.1600483288007f,0.16216196112149f,0.1642695184815f,0.166371019653566f,0.168466483322681f,0.170555928086473f,0.172639372455698f,0.174716834854712f,0.176788333621955f,0.178853887010421f,0.180913513188126f,0.182967230238583f,0.185015056161259f,0.18705700887204f,0.189093106203687f,0.191123365906294f,0.193147805647736f,0.195166443014119f,0.197179295510229f,0.19918638055997f,0.201187715506807f,0.203183317614203f,0.205173204066052f,0.207157391967109f,0.209135898343422f,0.211108740142754f,0.213075934235005f,0.215037497412637f,0.216993446391085f,0.218943797809176f,0.220888568229535f,0.222827774139f,0.224761431949025f,0.226689557996082f,0.228612168542064f,0.230529279774684f,0.232440907807868f,0.234347068682147f,0.236247778365053f,0.238143052751499f,0.24003290766417f,0.241917358853906f,0.243796422000076f,0.245670112710962f,0.247538446524132f,0.249401438906812f,0.251259105256259f,0.253111460900123f,0.254958521096822f,0.256800301035897f,0.258636815838374f,0.260468080557129f,0.262294110177234f,0.264114919616321f,0.265930523724925f,0.267740937286839f,0.269546175019461f,0.271346251574132f,0.273141181536489f,0.274930979426797f,0.276715659700291f,0.278495236747511f
+};
+
+static float v_to_c(float v){
+    // TODO use binary search.. lol
+    for (int i = 1; i < TSENSE_LOOKUP_LEN; i++) {
+        float cur = TSENSE_LOOKUP[i];
+        if (cur >= v) {
+            float prev = TSENSE_LOOKUP[i-1];
+
+            float ratio = (v - prev) / (cur - prev);
+            return TSENSE_T_MIN + ((float) i + ratio) * TSENSE_T_STEP;
+        }
+    }
+
+    return TSENSE_T_MAX;
+}
 
 static void __attribute__((noreturn)) analog_service(void *arg) {
     while (1) {
@@ -46,24 +77,31 @@ static void __attribute__((noreturn)) analog_service(void *arg) {
         adc_reading /= NO_OF_SAMPLES;
 
         //Convert adc_reading to voltage in mV
-        uint32_t voltage = esp_adc_cal_raw_to_voltage(adc_reading, adc_chars);
+        uint32_t mv = esp_adc_cal_raw_to_voltage(adc_reading, adc_chars);
 
 #define CORRECT -10;
-        voltage += CORRECT;
+        mv += CORRECT;
 
-//        printf("Raw: %d ... Voltage: %dmV ...", adc_reading, voltage);
+//        printf("Raw: %d ... Voltage: %dmV ...", adc_reading, mv);
 
-        float volts = voltage * 0.001f;
+        float volts = mv * 0.001f;
 
-#define R1 4750
+        float celsius = v_to_c(volts);
-#define V1 3.3f
+//        printf("Celsius: %.1f°C\n", celsius);
-        float r_pt100 = (volts * R1)/(V1 - volts);
-        float celsius = (r_pt100/100.0f - 1.0f) / 3.9083E-3f;
-//        printf("Rpt %.3f, Celsius: %.1f\n", r_pt100, celsius);
 
         measurement_celsius = celsius;
 
-        vTaskDelay(pdMS_TO_TICKS(100));
+        for (int i = 0; i < REG_HISTORY_LEN-1; i++) {
+            reg_meas_history[i] = reg_meas_history[i+1];
+            reg_tset_history[i] = reg_tset_history[i+1];
+        }
+        reg_meas_history[REG_HISTORY_LEN-1] = celsius;
+        reg_tset_history[REG_HISTORY_LEN-1] = fire_get_setpoint(true);
+        history_counter = (history_counter + 1) % 20;
+
+        fire_regulate(celsius);
+
+        vTaskDelay(pdMS_TO_TICKS(ANALOG_SAMPLE_TIME_MS));
     }
 }
 

main/analog.h

@@ -7,6 +7,15 @@
 #ifndef REFLOWER_ANALOG_H
 #define REFLOWER_ANALOG_H
 
+#include <stdint.h>
+
+#define ANALOG_SAMPLE_TIME_MS 1000
+
+#define REG_HISTORY_LEN 241
+extern float reg_meas_history[REG_HISTORY_LEN];
+extern float reg_tset_history[REG_HISTORY_LEN];
+extern uint32_t history_counter;
+
 void analog_init();
 
 float analog_read();

main/app_main.c

@@ -7,19 +7,90 @@
    CONDITIONS OF ANY KIND, either express or implied.
 */
 #include <stdio.h>
+#include <web/websrv.h>
+#include <esp_wifi.h>
+#include <esp_log.h>
 #include "freertos/FreeRTOS.h"
 #include "freertos/task.h"
 #include "esp_system.h"
 #include "esp_spi_flash.h"
-#include "nokia.h"
+#include "graphics/nokia.h"
 #include "knob.h"
 #include "gui.h"
 #include "analog.h"
+#include "utils.h"
+#include "esp_event_loop.h"
+#include "nvs_flash.h"
+#include "firehazard.h"
+
+/**
+ * Application event handler
+ *
+ * @param ctx - ignored, context passed to esp_event_loop_init()
+ * @param event
+ * @return success
+ */
+static esp_err_t event_handler(void *ctx, system_event_t *event)
+{
+    switch (event->event_id) {
+        case SYSTEM_EVENT_STA_START:
+            try_reconn_if_have_wifi_creds();
+            break;
+
+        case SYSTEM_EVENT_STA_CONNECTED:
+            // we should get an IP address soon
+            break;
+
+        case SYSTEM_EVENT_STA_GOT_IP:
+//            xEventGroupSetBits(g_wifi_event_group, EG_WIFI_CONNECTED_BIT);
+            break;
+
+        case SYSTEM_EVENT_STA_DISCONNECTED:
+//            xEventGroupClearBits(g_wifi_event_group, EG_WIFI_CONNECTED_BIT);
+            try_reconn_if_have_wifi_creds();
+            break;
+
+        default:
+            break;
+    }
+
+//    dhcp_watchdog_notify(dhcp_wd, event->event_id);
+
+    return ESP_OK;
+}
+
+
+/**
+ * Initialize WiFi in station mode, try to connect if settings are stored.
+ * Set up WiFi event group & start related tasks
+ */
+static void initialise_wifi(void)
+{
+    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+    ESP_ERROR_CHECK(esp_wifi_set_storage(WIFI_STORAGE_FLASH));
+    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
+
+    ESP_ERROR_CHECK(esp_wifi_start());
+}
 
 
 void __attribute__((noreturn)) app_main()
 {
-    printf("Hello world!\n");
+    // Initialize NVS
+    esp_err_t err = nvs_flash_init();
+    if (err == ESP_ERR_NVS_NO_FREE_PAGES || err == ESP_ERR_NVS_NEW_VERSION_FOUND) {
+        // NVS partition was truncated and needs to be erased
+        // Retry nvs_flash_init
+        ESP_ERROR_CHECK(nvs_flash_erase());
+        err = nvs_flash_init();
+    }
+    ESP_ERROR_CHECK( err );
+
+
+    //ESP_ERROR_CHECK(esp_register_shutdown_handler(cspemu_run_shutdown_handlers));
+
+    ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL));
 
     gpio_config_t output = {
         .pin_bit_mask = (1<<22),
@@ -27,11 +98,32 @@ void __attribute__((noreturn)) app_main()
     };
     gpio_config(&output);
 
+    tcpip_adapter_init();
+    initialise_wifi();
+
+#if 0
+    // TODO add proper join procedure
+    const char *ssid = "Chlivek_2.4G";
+    const char *pass = "slepice123";
+    wifi_config_t wifi_config = {};
+    strncpy((char*) wifi_config.sta.ssid, ssid, sizeof(wifi_config.sta.ssid));
+    if (pass) {
+        strncpy((char*) wifi_config.sta.password, pass, sizeof(wifi_config.sta.password));
+    }
+    ESP_ERROR_CHECK( esp_wifi_set_mode(WIFI_MODE_STA) );
+    ESP_ERROR_CHECK( esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config) );
+    ESP_ERROR_CHECK( esp_wifi_disconnect() );
+    ESP_ERROR_CHECK( esp_wifi_connect() );
+#endif
 
     gui_init();
     knob_init();
     analog_init();
 
+    try_reconn_if_have_wifi_creds();
+    websrv_init();
+    fire_init();
+
     bool level = 0;
     while (1) {
         vTaskDelay(pdMS_TO_TICKS(1000));

main/arduinopid.c

@@ -0,0 +1,106 @@
+#include "arduinopid.h"
+#include <stdbool.h>
+#include <stdint.h>
+#include <freertos/FreeRTOS.h>
+#include <freertos/task.h>
+
+static void clampOutput(struct PID *self) {
+    if (self->Output > self->outMax) self->Output = self->outMax;
+    else if (self->Output < self->outMin) self->Output = self->outMin;
+}
+
+static void clampIterm(struct PID *self) {
+    if (self->ITerm > self->outMax) self->ITerm = self->outMax;
+    else if (self->ITerm < self->outMin) self->ITerm = self->outMin;
+}
+
+void PID_Compute(struct PID *self, float Input)
+{
+    if (!self->ctlMode) return;
+    self->Input = Input;
+
+    uint32_t now = xTaskGetTickCount();
+    int32_t timeChange = (now - self->lastTime);
+    if (timeChange >= self->SampleTime) {
+        /*Compute all the working error variables*/
+        float error = self->Setpoint - Input;
+        self->ITerm += (self->ki * error);
+
+        clampIterm(self);
+
+        float dInput = (Input - self->lastInput);
+
+        /*Compute PID Output*/
+        self->Output = self->kp * error + self->ITerm - self->kd * dInput;
+
+        clampOutput(self);
+
+        /*Remember some variables for next time*/
+        self->lastInput = Input;
+        self->lastTime = now;
+    }
+}
+
+void PID_SetSetpoint(struct PID *self, float Setpoint)
+{
+    self->Setpoint = Setpoint;
+}
+
+void PID_SetTunings(struct PID *self, float Kp, float Ki, float Kd)
+{
+    if (Kp < 0 || Ki < 0 || Kd < 0) return;
+
+    float SampleTimeInSec = ((float) self->SampleTime) / 1000;
+    self->kp = Kp;
+    self->ki = Ki * SampleTimeInSec;
+    self->kd = Kd / SampleTimeInSec;
+
+    if (self->controllerDirection == PID_REVERSE) {
+        self->kp = -self->kp;
+        self->ki = -self->ki;
+        self->kd = -self->kd;
+    }
+}
+
+void PID_SetSampleTime(struct PID *self, uint32_t NewSampleTime)
+{
+    if (NewSampleTime > 0) {
+        float ratio = (float) NewSampleTime
+                      / (float) self->SampleTime;
+        self->ki *= ratio;
+        self->kd /= ratio;
+        self->SampleTime = (uint32_t) NewSampleTime;
+    }
+}
+
+void PID_SetOutputLimits(struct PID *self, float Min, float Max)
+{
+    if (Min > Max) return;
+    self->outMin = Min;
+    self->outMax = Max;
+
+    clampOutput(self);
+    clampIterm(self);
+}
+
+void PID_SetCtlMode(struct PID *self, enum PIDCtlMode Mode)
+{
+    bool newAuto = (Mode == PID_AUTOMATIC);
+    if (newAuto == !self->ctlMode) {  /*we just went from manual to auto*/
+        PID_Initialize(self);
+    }
+    self->ctlMode = newAuto;
+}
+
+void PID_Initialize(struct PID *self)
+{
+    self->lastInput = self->Input;
+    self->ITerm = self->Output;
+
+    clampIterm(self);
+}
+
+void PID_SetControllerDirection(struct PID *self, enum PIDDirection Direction)
+{
+    self->controllerDirection = Direction;
+}

main/arduinopid.h

@@ -0,0 +1,52 @@
+/**
+ * adapted from the Arduino PID library
+ * 
+ * Created on 2020/01/08.
+ */
+
+#ifndef ARDUINOPID_H
+#define ARDUINOPID_H
+
+#include <stdint.h>
+
+enum PIDCtlMode {
+    PID_MANUAL = 0,
+    PID_AUTOMATIC = 1,
+};
+
+enum PIDDirection {
+    PID_DIRECT = 0,
+    PID_REVERSE = 1,
+};
+
+struct PID {
+    /*working variables*/
+    uint32_t lastTime;
+    float Input, Output, Setpoint;
+    float ITerm, lastInput;
+    float kp, ki, kd;
+    uint32_t SampleTime; //1 sec  = 1000
+    float outMin, outMax;
+    enum PIDCtlMode ctlMode; // false
+    enum PIDDirection controllerDirection;
+};
+
+#define PID_DEFAULT() { .SampleTime = 1000, .ctlMode=PID_MANUAL, .controllerDirection=PID_DIRECT }
+
+void PID_Compute(struct PID *self, float Input);
+
+void PID_SetTunings(struct PID *self, float Kp, float Ki, float Kd);
+
+void PID_SetSampleTime(struct PID *self, uint32_t NewSampleTime);
+
+void PID_SetOutputLimits(struct PID *self, float Min, float Max);
+
+void PID_SetCtlMode(struct PID *self, enum PIDCtlMode Mode);
+
+void PID_Initialize(struct PID *self);
+
+void PID_SetSetpoint(struct PID *self, float Setpoint);
+
+void PID_SetControllerDirection(struct PID *self, enum PIDDirection Direction);
+
+#endif //ARDUINOPID_H

main/files/embed/chart.ignore.svg

@@ -0,0 +1,54 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 660 440">
+    <style>
+        .ticks, .frame {
+            stroke-width: 1px;
+            fill: none;
+            stroke: black;
+        }
+        
+        path.major {
+            stroke-width: 2px;
+        }
+        
+        .ylabels text {
+            font-size: 10px;
+            text-anchor: end;
+            font-family: Droid Sans, sans-serif;
+            vertical-align: middle;
+        }
+        
+        .grid {
+            stroke-dasharray: 4;
+            stroke: #999;
+        }
+        
+        .series {
+            stroke-width: 2px;
+            fill: none;
+        }
+    </style>
+    <g transform="translate(50,15)">
+        <path d="M100,0 v400m100,-400 v400m100,-400 v400m100,-400 v400m100,-400 v400m100,-400 v400m100,-400"
+              class="grid" transform="translate(0,0)" id="grid-v" />
+        <path d="M0,100 h600m-600,100 h600m-600,100 h600m-600,100"
+              class="grid" stroke-dashoffset="0" id="grid-h" />
+        <path d="M-10,0 h10m-10,100 h10m-10,100 h10m-10,100 h10m-10,100 h10" class="ticks" />
+        <path d="M-5,10
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,20
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,20
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,20
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5" class="ticks" />
+        <g class="series">
+            <path d="M0,400L600,0" stroke="blue" id="ser-set" />
+            <path d="M0,0L300,100L600,400" stroke="red" id="ser-actual" />
+        </g>
+        <path d="M0,0h600v400h-600Z" class="frame" />
+        <g class="ylabels" transform="translate(0,3)">
+            <text x="-15" y="0">400 °C</text>
+            <text x="-15" y="100">300 °C</text>
+            <text x="-15" y="200">200 °C</text>
+            <text x="-15" y="300">100 °C</text>
+            <text x="-15" y="400">0 °C</text>
+        </g>
+    </g>
+</svg>

main/files/embed/index.html

@@ -0,0 +1,166 @@
+<!DOCTYPE html>
+<html>
+<head>
+<meta charset="utf-8">
+<title>Breadflow Web Control</title>
+<style>
+    * {
+        box-sizing: content-box;
+    }
+    h1 { 
+        text-align: center;
+    }
+    #ctab {
+        width: 1400px;
+        margin: 0 auto;
+        border: 1px solid #ccc; 
+        border-collapse: collapse;
+    }
+    #td-side {
+        border-left: 1px solid #ccc;
+        width: 340px;
+        padding: 15px;
+        vertical-align: top;
+        padding-top: 22px;
+    }
+    #td-img {
+        vertical-align: top;
+    }
+</style>
+</head>
+<body>
+<h1>Breadflow {version}</h1>
+
+<table id="ctab">
+<tr>
+<td id="td-img">
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 660 430">
+    <style>
+    .ticks, .frame {
+        stroke-width: 1px;
+        fill: none;
+        stroke: black;
+    }
+    
+    .ylabels text {
+        font-size: 10px;
+        text-anchor: start;
+        font-family: Droid Sans, sans-serif;
+        vertical-align: middle;
+    }
+    
+    .grid {
+        stroke-dasharray: 2;
+        stroke: #dbdbdb;
+    }
+    
+    .series {
+        stroke-width: 2px;
+        fill: none;
+    }
+    </style>
+    <g transform="translate(10,15)">
+        <path d="M100,0 v400m100,-400 v400m100,-400 v400m100,-400 v400m100,-400 v400m100,-400 v400"
+            class="grid" transform="translate(0,0)" id="grid-v" />
+        <path d="M0,100 h600m-600,100 h600m-600,100 h600m-600,100"
+            class="grid" stroke-dashoffset="0" id="grid-h" />
+        <path d="M600,0 h10m-10,100 h10m-10,100 h10m-10,100 h10m-10,100 h10" class="ticks" />
+        <path d="M600,10
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,20
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,20
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,20
+                h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5m-5,10h5" class="ticks" />
+        <g class="series">
+            <path d="{ser-set}" stroke="blue" id="ser-set" /><!--M0,400L600,0-->
+            <path d="{ser-act}" stroke="red" id="ser-act" /><!--M0,0L300,100L600,400-->
+        </g>
+        <path d="M0,0h600v400h-600Z" class="frame" />
+        <g class="ylabels" transform="translate(630,3)">
+            <text x="-15" y="0">400 °C</text>
+            <text x="-15" y="100">300 °C</text>
+            <text x="-15" y="200">200 °C</text>
+            <text x="-15" y="300">100 °C</text>
+            <text x="-15" y="400">0 °C</text>
+        </g>
+    </g>
+</svg>
+</td>
+<td id="td-side">
+    t<sub>sens</sub> = <span id="temp">{temp}</span>°C<br>
+
+    <form action="/set" method="POST">
+        <h3>Oven Control</h3>
+        <table>
+            <tr>
+                <th>Heater:</th>
+                <td><select name="fire">
+                    <option value="0" {fire_dis_ck}>Disable</option>
+                    <option value="1" {fire_en_ck}>Enable</option>
+                </select></td>
+            </tr>
+            <tr>
+                <th>t<sub>set</sub> =</th>
+                <td><input type="number" step="1" name="tset" value="{tset}"></td>
+            </tr>
+            <tr><td></td><td><input type="submit" value="Set"></td></tr>
+        </table>
+    </form>
+
+    <form action="/set" method="POST">
+        <h3>PID tuning</h3>
+        <table>
+            <tr><th>Kp = </th><td><input type="number" step="any" name="kp" value="{kp}"></td></tr>
+            <tr><th>Ki = </th><td><input type="number" step="any" name="ki" value="{ki}"></td></tr>
+            <tr><th>Kd = </th><td><input type="number" step="any" name="kd" value="{kd}"></td></tr>
+            <tr><td></td><td><input type="submit" value="Set"></td></tr>
+        </table>
+    </form>
+</td>
+</tr>
+</table>
+
+<script>
+let Qi = function (x) { return document.getElementById(x) };
+const REFR_TIME = 1000;
+function update(data) {
+	if (data) {
+		let rows = data.split('\x1e');
+		rows.forEach(function (v) {
+			let [k, va] = v.split('\x1f');
+			switch (k) {
+			    case 'ser-set':
+			        Qi('ser-set').setAttribute('d', va);
+			        break;
+                case 'ser-act':
+                    Qi('ser-act').setAttribute('d', va);
+                    break;
+                case 'timeshift':
+                    Qi('grid-v').setAttribute('transform', 'translate(-'+(va*5)+',0)');
+                    Qi('grid-h').setAttribute('stroke-dashoffset', -va * 5);
+                    break;
+			    case 'temp':
+			        Qi('temp').innerHTML = va;
+			        break;
+			        // form fields are not live updated.
+            }
+		});
+	} else {
+		let xhr=new XMLHttpRequest();
+		xhr.onreadystatechange = function () {
+			if (xhr.readyState===4){
+				if (xhr.status===200) {
+					update(xhr.responseText);
+				}
+				setTimeout(update, REFR_TIME);
+			}
+		};
+		xhr.onerror = function () {
+			setTimeout(update, REFR_TIME);
+		};
+		xhr.open('GET', '/data');
+		xhr.send();
+	}
+}
+
+setTimeout(update, REFR_TIME);
+</script>

main/files/files_enum.c

@@ -0,0 +1,15 @@
+// Generated by 'rebuild_file_tables'
+#include <stdint.h>
+#include "files_enum.h"
+
+extern const uint8_t _binary_favicon_ico_start[];
+extern const uint8_t _binary_favicon_ico_end[];
+extern const uint8_t _binary_index_html_start[];
+extern const uint8_t _binary_index_html_end[];
+
+const struct embedded_file_info EMBEDDED_FILE_LOOKUP[] = {
+    [FILE_FAVICON_ICO] = {_binary_favicon_ico_start, _binary_favicon_ico_end, "favicon.ico", "image/vnd.microsoft.icon"},
+    [FILE_INDEX_HTML] = {_binary_index_html_start, _binary_index_html_end, "index.html", "text/html"},
+};
+
+const size_t EMBEDDED_FILE_LOOKUP_LEN = 2;

main/files/files_enum.h

@@ -0,0 +1,13 @@
+// Generated by 'rebuild_file_tables'
+
+#ifndef _EMBEDDED_FILES_ENUM_H
+#define _EMBEDDED_FILES_ENUM_H
+
+#include "fileserver/embedded_files.h"
+
+enum embedded_file_id {
+    FILE_FAVICON_ICO = 0,
+    FILE_INDEX_HTML = 1
+};
+
+#endif // _EMBEDDED_FILES_ENUM_H

main/files/rebuild_file_tables.php

@@ -0,0 +1,163 @@
+#!/usr/bin/env php
+<?php
+// This script rebuilds the static files enum, extern symbols pointing to the embedded byte buffers,
+// and the look-up structs table. To add more files, simply add them in the 'files' directory.
+
+// Note that all files will be accessible by the webserver, unless you filter them in embedded_files.c.
+
+
+// List all files
+$files = scandir(__DIR__.'/embed');
+
+$files = array_filter(array_map(function ($f) {
+  if (!is_file(__DIR__.'/embed/'.$f)) return null;
+  if (preg_match('/^\.|\.kate-swp|\.bak$|~$|\.sh|\.ignore\..*$/', $f)) return null;
+
+  echo "Found: $f\n";
+  return $f;
+}, $files));
+
+sort($files);
+
+$formatted = array_filter(array_map(function ($f) {
+  return "\"files/embed/$f\"";
+}, $files));
+
+$cmake = file_get_contents(__DIR__.'/../CMakeLists.txt');
+
+$cmake = preg_replace('/#begin staticfiles\n.*#end staticfiles/s', 
+  "#begin staticfiles\n".
+  "# generated by rebuild_file_tables\n".
+  "set(COMPONENT_EMBED_FILES\n        ".
+  implode("\n        ", $formatted) . ")\n".
+  "#end staticfiles", 
+  $cmake);
+
+file_put_contents(__DIR__.'/../CMakeLists.txt', $cmake);
+
+
+// Generate a list of files
+
+$num = 0;
+$enum_keys = array_map(function ($f) use(&$num) {
+  $a = preg_replace("/[^A-Z0-9_]+/", "_", strtoupper($f));
+  return 'FILE_'. $a.' = '.($num++);
+}, $files);
+
+$keylist = implode(",\n    ", $enum_keys);
+
+$struct_array = [];
+
+$externs = array_map(function ($f) use (&$struct_array) {
+  $a = preg_replace("/[^A-Z0-9_]+/", "_", strtoupper($f));
+  
+  $start = '_binary_'. strtolower($a).'_start';
+  $end = '_binary_'. strtolower($a).'_end';
+  
+  static $mimes = array(
+    'txt' => 'text/plain',
+    'htm' => 'text/html',
+    'html' => 'text/html',
+    'php' => 'text/html',
+    'css' => 'text/css',
+    'js' => 'application/javascript',
+    'json' => 'application/json',
+    'xml' => 'application/xml',
+    'swf' => 'application/x-shockwave-flash',
+    'flv' => 'video/x-flv',
+    
+    'pem' => 'application/x-pem-file',
+
+    // images
+    'png' => 'image/png',
+    'jpe' => 'image/jpeg',
+    'jpeg' => 'image/jpeg',
+    'jpg' => 'image/jpeg',
+    'gif' => 'image/gif',
+    'bmp' => 'image/bmp',
+    'ico' => 'image/vnd.microsoft.icon',
+    'tiff' => 'image/tiff',
+    'tif' => 'image/tiff',
+    'svg' => 'image/svg+xml',
+    'svgz' => 'image/svg+xml',
+
+    // archives
+    'zip' => 'application/zip',
+    'rar' => 'application/x-rar-compressed',
+    'exe' => 'application/x-msdownload',
+    'msi' => 'application/x-msdownload',
+    'cab' => 'application/vnd.ms-cab-compressed',
+
+    // audio/video
+    'mp3' => 'audio/mpeg',
+    'qt' => 'video/quicktime',
+    'mov' => 'video/quicktime',
+
+    // adobe
+    'pdf' => 'application/pdf',
+    'psd' => 'image/vnd.adobe.photoshop',
+    'ai' => 'application/postscript',
+    'eps' => 'application/postscript',
+    'ps' => 'application/postscript',
+
+    // ms office
+    'doc' => 'application/msword',
+    'rtf' => 'application/rtf',
+    'xls' => 'application/vnd.ms-excel',
+    'ppt' => 'application/vnd.ms-powerpoint',
+
+    // open office
+    'odt' => 'application/vnd.oasis.opendocument.text',
+    'ods' => 'application/vnd.oasis.opendocument.spreadsheet',
+  );
+  
+  $parts = explode('.', $f);
+  $suffix = end($parts);
+  $mime = $mimes[$suffix] ?? 'application/octet-stream';
+  
+  $len = filesize('embed/'.$f);
+  
+  $struct_array[] = "[FILE_$a] = {{$start}, {$end}, \"{$f}\", \"{$mime}\"},";
+  
+  return 
+    'extern const uint8_t '.$start.'[];'."\n".
+    'extern const uint8_t '.$end.'[];';
+}, $files);
+
+$externlist = implode("\n", $externs);
+$structlist = implode("\n    ", $struct_array);
+
+
+file_put_contents('files_enum.h', <<<FILE
+// Generated by 'rebuild_file_tables'
+
+#ifndef _EMBEDDED_FILES_ENUM_H
+#define _EMBEDDED_FILES_ENUM_H
+
+#include "fileserver/embedded_files.h"
+
+enum embedded_file_id {
+    $keylist
+};
+
+#endif // _EMBEDDED_FILES_ENUM_H
+
+FILE
+);
+
+$files_count = count($struct_array);
+file_put_contents("files_enum.c", <<<FILE
+// Generated by 'rebuild_file_tables'
+#include <stdint.h>
+#include "files_enum.h"
+
+$externlist
+
+const struct embedded_file_info EMBEDDED_FILE_LOOKUP[] = {
+    $structlist
+};
+
+const size_t EMBEDDED_FILE_LOOKUP_LEN = $files_count;
+
+FILE
+);

main/firehazard.c

@@ -0,0 +1,133 @@
+#include "firehazard.h"
+#include "arduinopid.h"
+#include <stdio.h>
+#include <stdbool.h>
+
+#include <math.h>
+#include <esp_log.h>
+#include <nvs.h>
+#include "driver/ledc.h"
+#include "esp_err.h"
+#include "utils.h"
+
+static const char *TAG = "fire";
+
+static struct PID pid = PID_DEFAULT();
+
+static void pwm_init(void);
+static void pwm_set(float duty);
+
+void fire_get_tuning(float *kp, float *ki, float *kd) {
+    *kp = pid.kp;
+    *ki = pid.ki;
+    *kd = pid.kd;
+}
+
+void fire_init() {
+    printf("Regulator init");
+
+    PID_Initialize(&pid);
+    PID_SetOutputLimits(&pid, 0, 1);
+    PID_SetCtlMode(&pid, PID_MANUAL);
+
+    nvs_handle nvs;
+    ESP_ERROR_CHECK(nvs_open("config", NVS_READWRITE, &nvs)); // must use RW to allow opening nonexistent
+    union uf32 kp, ki, kd;
+    kp.f = 0.4f;
+    ki.f = 0.5f;
+    kd.f = 0.0f;
+    nvs_get_u32(nvs, "kp", &kp.u);
+    nvs_get_u32(nvs, "ki", &ki.u);
+    nvs_get_u32(nvs, "kd", &kd.u);
+    PID_SetTunings(&pid, kp.f, ki.f, kd.f);
+    nvs_close(nvs);
+
+    pwm_init();
+
+    fire_setlevel(20);
+//    fire_enable(true);
+}
+
+void fire_set_tuning(float kp, float ki, float kd) {
+    ESP_LOGI(TAG, "PID set tuning Kp=%.3f, Ki=%.3f, Kd=%.3f", kp, ki, kd);
+    PID_SetTunings(&pid, kp, ki, kd);
+}
+
+float fire_get_setpoint(bool off_is_zero) {
+    if (off_is_zero) {
+        return pid.ctlMode == PID_MANUAL ? 0 : pid.Setpoint;
+    } else {
+        return pid.Setpoint;
+    }
+}
+
+void fire_setlevel(float cels) {
+    ESP_LOGI(TAG, "PID set target %.3f°C", cels);
+
+    if (cels < 0) cels = 0;
+    if (cels > MAX_SETPOINT) cels = MAX_SETPOINT;
+    PID_SetSetpoint(&pid, cels);
+}
+
+void fire_enable(bool enable) {
+    ESP_LOGI(TAG, "Heater %s", enable ? "enable" : "disable");
+
+    PID_SetCtlMode(&pid, enable ? PID_AUTOMATIC : PID_MANUAL);
+}
+
+bool fire_enabled() {
+    return pid.ctlMode == PID_AUTOMATIC;
+}
+
+void fire_regulate(float cels) {
+    PID_Compute(&pid, cels);
+
+    if (cels > MAX_TSENSE || cels < MIN_TSENSE) {
+        ESP_LOGE(TAG, "Tsense out of bounds! Stopping.");
+        fire_enable(false);
+    }
+
+    if (pid.ctlMode == PID_MANUAL) {
+        pwm_set(0);
+    } else {
+//        printf("PID in %.2f°C, out %.3f, I %.3f\n", cels, pid.Output, pid.ITerm);
+        pwm_set(pid.Output);
+    }
+}
+
+
+#define PWM_CHANNEL LEDC_CHANNEL_1
+#define PWM_TIMER LEDC_TIMER_1
+#define PWM_BIT_NUM LEDC_TIMER_12_BIT
+
+#define PWM_PIN GPIO_NUM_14
+
+static void pwm_init(void)
+{
+    ledc_channel_config_t ledc_channel_left = {0};
+    ledc_channel_left.gpio_num = PWM_PIN;
+    ledc_channel_left.speed_mode = LEDC_HIGH_SPEED_MODE;
+    ledc_channel_left.channel = PWM_CHANNEL;
+    ledc_channel_left.intr_type = LEDC_INTR_DISABLE;
+    ledc_channel_left.timer_sel = PWM_TIMER;
+    ledc_channel_left.duty = 0;
+
+    ledc_timer_config_t ledc_timer = {0};
+    ledc_timer.speed_mode = LEDC_HIGH_SPEED_MODE;
+    ledc_timer.duty_resolution = PWM_BIT_NUM;
+    ledc_timer.timer_num = PWM_TIMER;
+    ledc_timer.freq_hz = 1; // TODO ??
+
+    ESP_ERROR_CHECK( ledc_channel_config(&ledc_channel_left) );
+    ESP_ERROR_CHECK( ledc_timer_config(&ledc_timer) );
+}
+
+static void pwm_set(float duty)
+{
+    uint32_t max_duty = (1 << PWM_BIT_NUM);// - 1
+    uint32_t dutycycle = lroundf((duty) * (float)max_duty);
+//    printf("Dutycycle %d\n", dutycycle);
+
+    ESP_ERROR_CHECK( ledc_set_duty(LEDC_HIGH_SPEED_MODE, PWM_CHANNEL, dutycycle) );
+    ESP_ERROR_CHECK( ledc_update_duty(LEDC_HIGH_SPEED_MODE, PWM_CHANNEL) );
+}

main/firehazard.h

@@ -0,0 +1,25 @@
+/**
+ * TODO file description
+ * 
+ * Created on 2020/01/08.
+ */
+
+#ifndef REFLOWER_FIREHAZARD_H
+#define REFLOWER_FIREHAZARD_H
+#include <stdbool.h>
+
+#define MAX_SETPOINT 350
+#define MAX_TSENSE 400
+#define MIN_TSENSE 0
+
+void fire_regulate(float cels);
+void fire_init();
+void fire_setlevel(float cels);
+void fire_enable(bool enable);
+
+float fire_get_setpoint(bool off_is_zero);
+void fire_get_tuning(float *kp, float *ki, float *kd);
+bool fire_enabled();
+void fire_set_tuning(float kp, float ki, float kd);
+
+#endif //REFLOWER_FIREHAZARD_H

main/graphics/bitmaps.c

@@ -0,0 +1,124 @@
+#include "bitmaps.h"
+#include <stddef.h>
+#include <string.h>
+
+
+/* 21x22: no_flame */
+// ········██····█······
+// ·········██···██·····
+// ··········██·········
+// ··········███········
+// ·····█····███···█····
+// ···██····████··███···
+// ··██···█████··███····
+// ··█···█████··███·····
+// ·██··█████··███······
+// ·█··█████··███·······
+// ·█··████··███··█·····
+// ····███··███··███····
+// ·····█··███···███··█·
+// ·······███··█████··██
+// ·█····███··███████··█
+// █····███···███████···
+// ██··███··█··██████···
+// █··███··██···█████···
+// ··███··███···█████···
+// ·███··██·····█·███···
+// ███··█·········██····
+// ·█··███·······██·····
+static const uint8_t G_NO_FLAME_BYTES[] = { 0x00, 0x00, 0xc0, 0x60, 0x20, 0x10, 0x80, 0xc0, 0xc1, 0xe3, 0xfe, 0x7c, 0x38, 0x80, 0xc3, 0xe2, 0x70, 0x20, 0x00, 0x00, 0x00, 0x80, 0x47, 0x01, 0x00, 0x0e, 0x9f, 0xcf, 0xe7, 0x73, 0x39, 0x1c, 0xce, 0xe7, 0xe3, 0xf9, 0xfc, 0xf8, 0xc0, 0x00, 0x30, 0x60, 0x13, 0x39, 0x1c, 0x0e, 0x27, 0x33, 0x29, 0x0c, 0x06, 0x07, 0x00, 0x00, 0x01, 0x0f, 0x27, 0x3f, 0x1f, 0x0f, 0x00, 0x00, 0x00 };
+
+/* 21x22: flame */
+// ········██····█······
+// ·········██···██·····
+// ··········██·········
+// ··········███········
+// ·····█····███········
+// ···██····█████···█···
+// ··██···███████··█····
+// ··█···███████··██····
+// ·██··████████·██·····
+// ·█··████████··██·····
+// ·█··████████·███·····
+// ····████████·████····
+// ·····████·███·███··█·
+// ······███·███████··██
+// ·█·····██··███████··█
+// █·······██·███████···
+// ██·····███··██████···
+// █████·████···█████···
+// ·█████████···█████···
+// ··██████·····█·███···
+// ···███·········██····
+// ····███·······██·····
+static const uint8_t G_FLAME_BYTES[] = { 0x00, 0x00, 0xc0, 0x60, 0x20, 0x10, 0x80, 0xc0, 0xc1, 0xe3, 0xfe, 0xfc, 0xf8, 0x60, 0x03, 0x82, 0xc0, 0x20, 0x00, 0x00, 0x00, 0x80, 0x47, 0x01, 0x00, 0x0e, 0x1f, 0x3f, 0x7f, 0xff, 0x8f, 0x3f, 0xff, 0xf1, 0xec, 0xff, 0xff, 0xf8, 0xc0, 0x00, 0x30, 0x60, 0x03, 0x07, 0x0e, 0x1e, 0x3e, 0x3c, 0x2e, 0x0f, 0x07, 0x07, 0x00, 0x00, 0x01, 0x0f, 0x27, 0x3f, 0x1f, 0x0f, 0x00, 0x00, 0x00 };
+
+/* 84x48: boot_logo */
+// ····················································································
+// ·····································································████████·······
+// ························································█████████████····█···██·····
+// ···················█·······························█████····█·███·····███······█····
+// ······█·█····································██████···██·█████··███████·········█···
+// ·······█······························███████····██·█████·█·······███··········█····
+// ······█·█······················███████·····███·███████··██···················██·····
+// ···························██████·██·███·███·███████████·████·············███·······
+// ······················████████████·██··███··█████████·█████·············██·██·······
+// ··················█████·██·████···█·████···███████·███·············█████···██·······
+// ·············███████████·█████████████···██·······█············█████··█·█·█·██······
+// ············██████████·██████████··███████·················█████··█·██·█···███······
+// ·········██████··█··████·██·███···████·█···············████···█··███··█······██·····
+// ······███·████████████████████··██················█████··█···█·█·█···········█·█····
+// ···███████····················██··············████·█····█·····█················█····
+// ····██··························█·············█···█····██······················█····
+// ··██·····························█·······█·█·█···█····██·······················█····
+// ·█······························█·······█·█·█···█·█····························█····
+// ·█····························██·······█·█·█·····█····················█········█····
+// ··██······················████·█·█·█··█·······························█······█··█···
+// ····████···················█··█·█·█··█································█······█··█···
+// ·······█···················██·█·██··························█·········█······█··█···
+// ·······█····················█·██······█·····················█··········█·····█··█···
+// ·······█····················█·█········█··········█··········█·········█·····███····
+// ········█···················█··········█···········█·········█·····██████████·······
+// ········█····················█·········█············█·········█·███·················
+// ········█····················█··········█···········█·······████····················
+// ········█·····················█·········█············█·█████························
+// ········█······················█·········█·········████·····························
+// ········█·······················█········█····█████···██················█·█·········
+// ·········█······················█·········█·██···························█··········
+// ·········█······················█·······████····························█·█·········
+// ·········█······················█····███·····················█······················
+// ·········█·······················████·······················███·····················
+// ·········█·····················███···························█······················
+// ·········█········██████████████····················································
+// ··········█·██████·····························································█····
+// ···········█····························································█······█····
+// ··························································█············█·······█····
+// ··████·································█··················█······██····█··█····█····
+// ··█···█···██████···█████████····█·····███████···███████···█·····█··█····█·██····█···
+// ··█···█··██·····█·█·█··········█·█······█····█·█·█·······█·····█····█···█··█····█···
+// ··████····█·····██··█··········█·█······█····█···██████··█·····█····█···█··█····█···
+// ··█···█···██████··███████·····█···█·····█···█··███·······█·····█···█·····█·██···█···
+// ··█····█··██········█········███████····█··█·····█·······█······█·█······█·█·█·█····
+// ··█···█···█·██······█·····██··█····█··█████······█········█████··█········█···█·····
+// ██████····█···███····█████···█·····██············█··································
+// ··········█·····█···································································
+static const uint8_t G_BOOT_LOGO_BYTES[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x50, 0x20, 0x50, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x80, 0x80, 0x80, 0xc0, 0xc0, 0x40, 0xc0, 0xc0, 0x40, 0xc0, 0xa0, 0xa0, 0x20, 0xa0, 0xa0, 0xe0, 0x60, 0xd0, 0x90, 0xd0, 0xd0, 0xf0, 0xf0, 0xc8, 0xe8, 0xe8, 0xb8, 0xb8, 0x64, 0xd4, 0xb4, 0x94, 0x9c, 0x14, 0x0c, 0x0c, 0x1c, 0x14, 0x34, 0x34, 0x34, 0x12, 0x1a, 0x0a, 0x0a, 0x06, 0x82, 0x82, 0x82, 0x44, 0x44, 0x28, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x40, 0xc0, 0xc0, 0x60, 0x60, 0x60, 0x50, 0x30, 0x30, 0x38, 0x3c, 0x3c, 0x2c, 0x2c, 0x3c, 0x2e, 0x2e, 0x3e, 0x3e, 0x37, 0x3d, 0x2b, 0x3f, 0x3d, 0x2f, 0x3f, 0x3f, 0x5f, 0x4d, 0xad, 0x25, 0x16, 0x1d, 0x1f, 0x1e, 0x0a, 0x1b, 0x09, 0x0d, 0x04, 0x02, 0x03, 0x03, 0xc3, 0x43, 0x43, 0x43, 0xa5, 0x63, 0x23, 0x22, 0x21, 0x91, 0xd1, 0x31, 0x11, 0x08, 0x08, 0x28, 0x58, 0x2c, 0x04, 0x34, 0x1c, 0x16, 0x0a, 0x0a, 0x16, 0x0a, 0x05, 0x01, 0x04, 0x0b, 0x0f, 0x3c, 0x10, 0xe0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x06, 0x09, 0x09, 0x10, 0x10, 0x10, 0xf0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, 0x38, 0xe8, 0x08, 0xf4, 0x4c, 0x32, 0x29, 0x10, 0x08, 0x00, 0x10, 0x48, 0x84, 0x02, 0x05, 0x02, 0x05, 0x02, 0x01, 0x00, 0x00, 0x02, 0x05, 0x82, 0x00, 0x00, 0x00, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x60, 0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3c, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0xf8, 0x80, 0x87, 0x78, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x3f, 0xc0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x06, 0x08, 0x10, 0xe0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03, 0x8c, 0xb0, 0xc0, 0x80, 0x40, 0x40, 0x20, 0x20, 0x20, 0x20, 0x20, 0x11, 0x16, 0x18, 0x30, 0x28, 0x08, 0x08, 0x08, 0x08, 0x04, 0x05, 0x06, 0x04, 0x02, 0x02, 0x02, 0x01, 0x01, 0x01, 0x01, 0x01, 0xa1, 0x41, 0xa1, 0x01, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x80, 0x80, 0x80, 0x80, 0x00, 0x00, 0x00, 0x0f, 0x10, 0x20, 0x10, 0x10, 0x10, 0x10, 0x10, 0x10, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x08, 0x0c, 0x05, 0x06, 0x02, 0x02, 0x02, 0x01, 0x01, 0x81, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xc0, 0x00, 0x02, 0x07, 0x02, 0x00, 0x00, 0x80, 0x80, 0x00, 0x00, 0x00, 0x00, 0xc0, 0x20, 0x00, 0x80, 0x00, 0x00, 0x00, 0x00, 0xf0, 0x00, 0x00, 0x00, 0x00, 0x40, 0x40, 0x7f, 0x44, 0x44, 0x44, 0x2b, 0x10, 0x00, 0x02, 0xff, 0x19, 0x29, 0x29, 0x49, 0x49, 0xc6, 0x04, 0x0a, 0x09, 0x3f, 0x49, 0x49, 0x49, 0x49, 0x41, 0x21, 0x21, 0x00, 0x50, 0x38, 0x16, 0x11, 0x16, 0x18, 0x70, 0x40, 0x00, 0x21, 0x21, 0x3f, 0x21, 0x21, 0x11, 0x09, 0x06, 0x00, 0x0a, 0x09, 0x7f, 0x05, 0x05, 0x05, 0x05, 0x05, 0x00, 0x00, 0x1e, 0x21, 0x20, 0x20, 0x20, 0x20, 0x0e, 0x11, 0x20, 0x10, 0x09, 0x06, 0x00, 0x00, 0x00, 0x07, 0x18, 0x21, 0x1f, 0x08, 0x10, 0x20, 0x10, 0x0f, 0x00, 0x00, 0x00 };
+
+static const struct BitmapImage bitmaps[] = { 
+    { .name="no_flame", .width=21, .height=22, .bytes=G_NO_FLAME_BYTES },
+    { .name="flame", .width=21, .height=22, .bytes=G_FLAME_BYTES },
+    { .name="boot_logo", .width=84, .height=48, .bytes=G_BOOT_LOGO_BYTES },
+    {}
+};
+
+const struct BitmapImage *Bitmap_Get(const char *name) {
+    const struct BitmapImage *ptr = &bitmaps[0];
+    while (ptr->name) {
+        if (0 == strcmp(ptr->name, name)) {
+            return ptr;
+        }
+        ptr++;
+    }
+    return NULL;
+}
+    

main/graphics/bitmaps.h

@@ -0,0 +1,21 @@
+/**
+ * TODO file description
+ * 
+ * Created on 2020/01/05.
+ */
+
+#ifndef BITMAPS_H
+#define BITMAPS_H
+
+#include <stdint.h>
+
+struct BitmapImage {
+    const char *name;
+    uint8_t width;
+    uint8_t height;
+    const uint8_t* bytes;
+};
+
+const struct BitmapImage *Bitmap_Get(const char *name);
+
+#endif //BITMAPS_H

main/graphics/display_spec.h

@@ -0,0 +1,13 @@
+/**
+ * TODO file description
+ * 
+ * Created on 2020/01/05.
+ */
+
+#ifndef REFLOWER_DISPLAY_SPEC_H
+#define REFLOWER_DISPLAY_SPEC_H
+
+#define LCD_WIDTH   84 // Note: x-coordinates go wide
+#define LCD_HEIGHT  48 // Note: y-coordinates go high
+
+#endif //REFLOWER_DISPLAY_SPEC_H

main/graphics/drawing.c

@@ -0,0 +1,369 @@
+#include "drawing.h"
+#include "display_spec.h"
+#include "font.h"
+#include "bitmaps.h"
+
+extern uint8_t LCD_displayMap[LCD_WIDTH * LCD_HEIGHT / 8];
+
+// This function sets a pixel on displayMap to your preferred
+// color. 1=Black, 0= white.
+void LCD_setPixel(int x, int y, enum Color bw)
+{
+    // First, double check that the coordinate is in range.
+    if ((x >= 0) && (x < LCD_WIDTH) && (y >= 0) && (y < LCD_HEIGHT)) {
+        uint8_t shift = y % 8;
+
+        if (bw) // If black, set the bit.
+            LCD_displayMap[x + (y / 8) * LCD_WIDTH] |= 1 << shift;
+        else   // If white clear the bit.
+            LCD_displayMap[x + (y / 8) * LCD_WIDTH] &= ~(1 << shift);
+    }
+}
+
+// setLine draws a line from x0,y0 to x1,y1 with the set color.
+// This function was grabbed from the SparkFun ColorLCDShield
+// library.
+void LCD_setLine(int x0, int y0, int x1, int y1, enum Color bw)
+{
+    int dy = y1 - y0; // Difference between y0 and y1
+    int dx = x1 - x0; // Difference between x0 and x1
+    int stepx, stepy;
+
+    if (dy < 0) {
+        dy = -dy;
+        stepy = -1;
+    }
+    else
+        stepy = 1;
+
+    if (dx < 0) {
+        dx = -dx;
+        stepx = -1;
+    }
+    else
+        stepx = 1;
+
+    dy <<= 1; // dy is now 2*dy
+    dx <<= 1; // dx is now 2*dx
+    LCD_setPixel(x0, y0, bw); // Draw the first pixel.
+
+    if (dx > dy) {
+        int fraction = dy - (dx >> 1);
+        while (x0 != x1) {
+            if (fraction >= 0) {
+                y0 += stepy;
+                fraction -= dx;
+            }
+            x0 += stepx;
+            fraction += dy;
+            LCD_setPixel(x0, y0, bw);
+        }
+    }
+    else {
+        int fraction = dx - (dy >> 1);
+        while (y0 != y1) {
+            if (fraction >= 0) {
+                x0 += stepx;
+                fraction -= dy;
+            }
+            y0 += stepy;
+            fraction += dx;
+            LCD_setPixel(x0, y0, bw);
+        }
+    }
+}
+
+// setRect will draw a rectangle from x0,y0 top-left corner to
+// a x1,y1 bottom-right corner. Can be filled with the fill
+// parameter, and colored with bw.
+// This function was grabbed from the SparkFun ColorLCDShield
+// library.
+void LCD_setRect(int x0, int y0, int x1, int y1, bool fill, enum Color bw)
+{
+    // check if the rectangle is to be filled
+    if (fill == 1) {
+        int xDiff;
+
+        if (x0 > x1)
+            xDiff = x0 - x1; //Find the difference between the x vars
+        else
+            xDiff = x1 - x0;
+
+        while (xDiff >= 0) {
+            LCD_setLine(x0, y0, x0, y1, bw);
+
+            if (x0 > x1)
+                x0--;
+            else
+                x0++;
+
+            xDiff--;
+        }
+    }
+    else {
+        // best way to draw an unfilled rectangle is to draw four lines
+        LCD_setLine(x0, y0, x1, y0, bw);
+        LCD_setLine(x0, y1, x1, y1, bw);
+        LCD_setLine(x0, y0, x0, y1, bw);
+        LCD_setLine(x1, y0, x1, y1, bw);
+    }
+}
+
+// setCircle draws a circle centered around x0,y0 with a defined
+// radius. The circle can be black or white. And have a line
+// thickness ranging from 1 to the radius of the circle.
+// This function was grabbed from the SparkFun ColorLCDShield
+// library.
+void LCD_setCircle(int x0, int y0, int radius, enum Color bw, int lineThickness)
+{
+    for (int r = 0; r < lineThickness; r++) {
+        int f = 1 - radius;
+        int ddF_x = 0;
+        int ddF_y = -2 * radius;
+        int x = 0;
+        int y = radius;
+
+        LCD_setPixel(x0, y0 + radius, bw);
+        LCD_setPixel(x0, y0 - radius, bw);
+        LCD_setPixel(x0 + radius, y0, bw);
+        LCD_setPixel(x0 - radius, y0, bw);
+
+        while (x < y) {
+            if (f >= 0) {
+                y--;
+                ddF_y += 2;
+                f += ddF_y;
+            }
+            x++;
+            ddF_x += 2;
+            f += ddF_x + 1;
+
+            LCD_setPixel(x0 + x, y0 + y, bw);
+            LCD_setPixel(x0 - x, y0 + y, bw);
+            LCD_setPixel(x0 + x, y0 - y, bw);
+            LCD_setPixel(x0 - x, y0 - y, bw);
+            LCD_setPixel(x0 + y, y0 + x, bw);
+            LCD_setPixel(x0 - y, y0 + x, bw);
+            LCD_setPixel(x0 + y, y0 - x, bw);
+            LCD_setPixel(x0 - y, y0 - x, bw);
+        }
+        radius--;
+    }
+}
+
+static void LCD_setCharEx(struct Utf8Char character, int x, int y, enum Color color, struct TextStyle style)
+{
+    const struct FontGraphic *symbol = Font_GetSymbol(character);
+
+    uint8_t column; // temp byte to store character's column bitmap
+    for (int i = 0; i < 5; i++) // 5 columns (x) per character
+    {
+        column = symbol->columns[i];
+        for (int j = 0; j < 8; j++) // 8 rows (y) per character
+        {
+            bool bit = column & (1 << j);
+
+            if (style.size == FONT_NORMAL) {
+                if (bit) {// test bits to set pixels
+                    LCD_setPixel(x + i, y + j, color);
+                }
+                else if (style.bg) {
+                    LCD_setPixel(x + i, y + j, !color);
+                }
+            }
+            else if (style.size == FONT_DOUBLE) {
+                if (bit) {// test bits to set pixels
+                    LCD_setPixel(x + i * 2, y + j * 2, color);
+                    LCD_setPixel(x + i * 2 + 1, y + j * 2, color);
+                    LCD_setPixel(x + i * 2, y + j * 2 + 1, color);
+                    LCD_setPixel(x + i * 2 + 1, y + j * 2 + 1, color);
+                }
+                else if (style.bg) {
+                    LCD_setPixel(x + i * 2, y + j * 2, !color);
+                    LCD_setPixel(x + i * 2 + 1, y + j * 2, !color);
+                    LCD_setPixel(x + i * 2, y + j * 2 + 1, !color);
+                    LCD_setPixel(x + i * 2 + 1, y + j * 2 + 1, !color);
+                }
+            }
+            else if (style.size == FONT_BOLD) {
+                if (bit) {// test bits to set pixels
+                    LCD_setPixel(x + i, y + j, color);
+                    LCD_setPixel(x + i + 1, y + j, color);
+                }
+                else if (style.bg) {
+                    LCD_setPixel(x + i, y + j, !color);
+                    LCD_setPixel(x + i + 1, y + j, !color);
+                }
+            }
+        }
+    }
+}
+
+// setStr draws a string of characters, calling setChar with
+// progressive coordinates until it's done.
+// This function was grabbed from the SparkFun ColorLCDShield
+// library.
+void LCD_setStr(const char *dString, int x, int y, enum Color bw)
+{
+    LCD_setStrEx(dString, x, y, bw, (struct TextStyle) {});
+}
+
+static const int char_widths[] = {
+    [FONT_NORMAL] = 5,
+    [FONT_DOUBLE] = 10,
+    [FONT_BOLD] = 6
+};
+
+static const int char_spacings[] = {
+    [FONT_NORMAL] = 1,
+    [FONT_DOUBLE] = 2,
+    [FONT_BOLD] = 1
+};
+
+static const int char_heights[] = {
+    [FONT_NORMAL] = 8,
+    [FONT_DOUBLE] = 16,
+    [FONT_BOLD] = 8
+};
+
+// setStr draws a string of characters, calling setChar with
+// progressive coordinates until it's done.
+// This function was grabbed from the SparkFun ColorLCDShield
+// library. AND HEAVILY MODIFIED
+void LCD_setStrEx(const char *dString, int x, int y, enum Color color, struct TextStyle style)
+{
+    struct Utf8Char uchar;
+    struct Utf8Iterator iter;
+    Utf8Iterator_Init(&iter, dString);
+
+    int charw = char_widths[style.size];
+    int charh = char_heights[style.size];
+    int spacingx = char_spacings[style.size] + style.spacing_x;
+    int spacingy = style.spacing_y;
+
+    if (style.align != ALIGN_LEFT) {
+        int line_len = 0;
+        int skip = style.skip;
+        while ((uchar = Utf8Iterator_Next(&iter)).uint) {
+            if (skip > 0) {
+                skip -= 1;
+                continue;
+            }
+            if (uchar.bytes[0] == '\n') {
+                break;
+            }
+            line_len++;
+        }
+        if (style.align == ALIGN_CENTER) {
+            x -= ((charw + spacingx) * line_len) / 2 - spacingx/2;
+        } else {
+            // right
+            x -= ((charw + spacingx) * line_len) - spacingx;
+        }
+    }
+
+    const int x0 = x;
+    Utf8Iterator_Init(&iter, dString);
+
+    int limit = style.limit;
+    int skip = style.skip;
+    bool wrap;
+    while ((uchar = Utf8Iterator_Next(&iter)).uint) {
+        if (skip > 0) {
+            skip -= 1;
+            continue;
+        }
+
+        wrap = uchar.bytes[0] == '\n';
+
+        if (!wrap) LCD_setCharEx(uchar, x, y, color, style);
+
+        if (limit > 0) {
+            limit -= 1;
+            if (limit == 0) return;
+        }
+
+        if (!wrap) {
+            x += charw;
+            if (style.bg) {
+                for (int i = y; i < y + charh; i++) {
+                    for (int j = x; j < x + spacingx; j++) {
+                        LCD_setPixel(j, i, !color);
+                    }
+                }
+            }
+        }
+
+        x += spacingx;
+        if (wrap || x > (LCD_WIDTH - charw)) {
+            if (style.nowrap) break;
+            if (style.wrap_to_0) {
+                x = 0;
+            } else {
+                x = x0;
+            }
+            y += charh + spacingy;
+        }
+
+        // no more characters could be seen
+        if (y >= LCD_HEIGHT) {
+            break;
+        }
+    }
+}
+
+// This function will draw an array over the screen. (For now) the
+// array must be the same size as the screen, covering the entirety
+// of the display.
+void LCD_setBitmapFullScreen(const uint8_t *bitArray)
+{
+    for (int i = 0; i < sizeof(LCD_displayMap); i++) {
+        LCD_displayMap[i] = bitArray[i];
+    }
+}
+
+void LCD_setBitmap(const struct BitmapImage *image, int x, int y, bool bg, enum Color color)
+{
+//    int byte_count = image->width * ((image->height + 7) / 8);
+
+    for (int xi = 0; xi < image->width; xi++) {
+        for (int yi = 0; yi < image->height; yi++) {
+            int idx = xi + (yi / 8) * image->width;
+//            if (idx > byte_count) continue;
+            bool bit = image->bytes[idx] & (1 << (yi % 8));
+            if (bit) {
+                LCD_setPixel(x + xi, y + yi, color);
+            }
+            else if (bg) {
+                LCD_setPixel(x + xi, y + yi, !color);
+            }
+        }
+    }
+}
+
+// This function clears the entire display either white (0) or
+// black (1).
+// The screen won't actually clear until you call updateDisplay()!
+void LCD_clearDisplay(enum Color bw)
+{
+    for (int i = 0; i < (LCD_WIDTH * LCD_HEIGHT / 8); i++) {
+        if (bw)
+            LCD_displayMap[i] = 0xFF;
+        else
+            LCD_displayMap[i] = 0;
+    }
+}
+
+void LCD_invertDisplayData()
+{
+    /* Indirect, swap bits in displayMap option: */
+    for (int i = 0; i < (LCD_WIDTH * LCD_HEIGHT / 8); i++) {
+        LCD_displayMap[i] ^= 0xFF;
+    }
+}
+
+void LCD_setShadeOverlay() {
+    for (int i = 0; i < (LCD_WIDTH * LCD_HEIGHT / 8); i++) {
+        LCD_displayMap[i] |= i & 1 ? 0x88 : 0x22;
+    }
+}

main/graphics/drawing.h

@@ -0,0 +1,93 @@
+/**
+ * TODO file description
+ * 
+ * Created on 2020/01/05.
+ */
+
+#ifndef LCD_DRAWING_H
+#define LCD_DRAWING_H
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include "utf8.h"
+#include "bitmaps.h"
+
+enum Color {
+    WHITE = 0,
+    BLACK = 1,
+};
+
+// This function sets a pixel on displayMap to your preferred
+// color. 1=Black, 0= white.
+void LCD_setPixel(int x, int y, enum Color bw);
+
+// setLine draws a line from x0,y0 to x1,y1 with the set color
+void LCD_setLine(int x0, int y0, int x1, int y1, enum Color bw);
+
+// setRect will draw a rectangle from x0,y0 top-left corner to
+// a x1,y1 bottom-right corner. Can be filled with the fill
+// parameter, and colored with bw.
+void LCD_setRect(int x0, int y0, int x1, int y1, bool fill, enum Color bw);
+
+// setCircle draws a circle centered around x0,y0 with a defined
+// radius. The circle can be black or white. And have a line
+// thickness ranging from 1 to the radius of the circle.
+void LCD_setCircle (int x0, int y0, int radius, enum Color bw, int lineThickness);
+
+void LCD_setBitmapFullScreen(const uint8_t *bitArray);
+
+/*
+ FONT FUNCTIONS
+ size = 1 ... normal
+ size = 2 ... 2x
+ size = 3 ... normal bold
+ size | 0x80 ... clear background behind characters
+*/
+
+enum TextSize {
+    FONT_NORMAL = 0,
+    FONT_DOUBLE = 1,
+    FONT_BOLD = 2,
+};
+
+enum TextAlign {
+    ALIGN_LEFT = 0,
+    ALIGN_CENTER = 1,
+    ALIGN_RIGHT = 2,
+};
+
+struct TextStyle {
+    bool bg;              //!< Fill the characters background with the opposite color
+    enum TextSize size;   //!< Character size
+    enum TextAlign align; //!< Alignment (works only for single line)
+    size_t limit;            //!< Number of characters to print from the string, if > 0
+    size_t skip;             //!< Characters to skip before printing
+    int spacing_x;        //!< Additional X spacing
+    int spacing_y;        //!< Additional Y spacing
+    bool nowrap;          //!< Stop painting when the right edge of the screen is reached
+    bool wrap_to_0;       //!< wrap to 0 instead of the initial X coordinate
+};
+
+// setStr draws a string of characters, calling setChar with
+// progressive coordinates until it's done.
+// This function was grabbed from the SparkFun ColorLCDShield
+// library.
+void LCD_setStr(const char * dString, int x, int y, enum Color bw);
+
+void LCD_setStrEx(const char *dString, int x, int y, enum Color color, struct TextStyle style);
+
+// This function clears the entire display either white (0) or
+// black (1).
+// The screen won't actually clear until you call updateDisplay()!
+void LCD_clearDisplay(enum Color bw);
+
+/* Invert colors (hard change in data; does NOT send to display immediately) */
+void LCD_invertDisplayData();
+
+void LCD_setBitmap(const struct BitmapImage *image, int x, int y, bool bg, enum Color color);
+
+/** draw dotted shadow over current content */
+void LCD_setShadeOverlay();
+
+#endif //LCD_DRAWING_H

main/graphics/font.c

@@ -0,0 +1,159 @@
+#include "font.h"
+#include "utf8.h"
+#include <stdint.h>
+
+#define FONT_EXTRAS_START (0x7e - 0x20 + 1)
+
+struct Utf8Symbol {
+    union {
+        const char symbol[4];
+        const uint32_t uint;
+    };
+    struct FontGraphic graphic;
+};
+
+// ASCII symbols are stored as bare graphic to reduce ROM size
+const struct FontGraphic ascii_glyphs[95] = {
+    {{0x00, 0x00, 0x00, 0x00, 0x00}}, // " 0x20
+    {{0x00, 0x00, 0x5f, 0x00, 0x00}}, // ! 0x21
+    {{0x00, 0x07, 0x00, 0x07, 0x00}}, // \" 0x22
+    {{0x14, 0x7f, 0x14, 0x7f, 0x14}}, // # 0x23
+    {{0x24, 0x2a, 0x7f, 0x2a, 0x12}}, // $ 0x24
+    {{0x23, 0x13, 0x08, 0x64, 0x62}}, // % 0x25
+    {{0x36, 0x49, 0x55, 0x22, 0x50}}, // & 0x26
+    {{0x00, 0x05, 0x03, 0x00, 0x00}}, // ' 0x27
+    {{0x00, 0x1c, 0x22, 0x41, 0x00}}, // ( 0x28
+    {{0x00, 0x41, 0x22, 0x1c, 0x00}}, // ) 0x29
+    {{0x14, 0x08, 0x3e, 0x08, 0x14}}, // * 0x2a
+    {{0x08, 0x08, 0x3e, 0x08, 0x08}}, // + 0x2b
+    {{0x00, 0x50, 0x30, 0x00, 0x00}}, // , 0x2c
+    {{0x08, 0x08, 0x08, 0x08, 0x08}}, // - 0x2d
+    {{0x00, 0x60, 0x60, 0x00, 0x00}}, // . 0x2e
+    {{0x20, 0x10, 0x08, 0x04, 0x02}}, // / 0x2f
+    {{0x3e, 0x51, 0x49, 0x45, 0x3e}}, // 0 0x30
+    {{0x00, 0x42, 0x7f, 0x40, 0x00}}, // 1 0x31
+    {{0x42, 0x61, 0x51, 0x49, 0x46}}, // 2 0x32
+    {{0x21, 0x41, 0x45, 0x4b, 0x31}}, // 3 0x33
+    {{0x18, 0x14, 0x12, 0x7f, 0x10}}, // 4 0x34
+    {{0x27, 0x45, 0x45, 0x45, 0x39}}, // 5 0x35
+    {{0x3c, 0x4a, 0x49, 0x49, 0x30}}, // 6 0x36
+    {{0x01, 0x71, 0x09, 0x05, 0x03}}, // 7 0x37
+    {{0x36, 0x49, 0x49, 0x49, 0x36}}, // 8 0x38
+    {{0x06, 0x49, 0x49, 0x29, 0x1e}}, // 9 0x39
+    {{0x00, 0x36, 0x36, 0x00, 0x00}}, // : 0x3a
+    {{0x00, 0x56, 0x36, 0x00, 0x00}}, // ; 0x3b
+    {{0x08, 0x14, 0x22, 0x41, 0x00}}, // < 0x3c
+    {{0x14, 0x14, 0x14, 0x14, 0x14}}, // = 0x3d
+    {{0x00, 0x41, 0x22, 0x14, 0x08}}, // > 0x3e
+    {{0x02, 0x01, 0x51, 0x09, 0x06}}, // ? 0x3f
+    {{0x32, 0x49, 0x79, 0x41, 0x3e}}, // @ 0x40
+    {{0x7e, 0x11, 0x11, 0x11, 0x7e}}, // A 0x41
+    {{0x7f, 0x49, 0x49, 0x49, 0x36}}, // B 0x42
+    {{0x3e, 0x41, 0x41, 0x41, 0x22}}, // C 0x43
+    {{0x7f, 0x41, 0x41, 0x22, 0x1c}}, // D 0x44
+    {{0x7f, 0x49, 0x49, 0x49, 0x41}}, // E 0x45
+    {{0x7f, 0x09, 0x09, 0x09, 0x01}}, // F 0x46
+    {{0x3e, 0x41, 0x49, 0x49, 0x7a}}, // G 0x47
+    {{0x7f, 0x08, 0x08, 0x08, 0x7f}}, // H 0x48
+    {{0x00, 0x41, 0x7f, 0x41, 0x00}}, // I 0x49
+    {{0x20, 0x40, 0x41, 0x3f, 0x01}}, // J 0x4a
+    {{0x7f, 0x08, 0x14, 0x22, 0x41}}, // K 0x4b
+    {{0x7f, 0x40, 0x40, 0x40, 0x40}}, // L 0x4c
+    {{0x7f, 0x02, 0x0c, 0x02, 0x7f}}, // M 0x4d
+    {{0x7f, 0x04, 0x08, 0x10, 0x7f}}, // N 0x4e
+    {{0x3e, 0x41, 0x41, 0x41, 0x3e}}, // O 0x4f
+    {{0x7f, 0x09, 0x09, 0x09, 0x06}}, // P 0x50
+    {{0x3e, 0x41, 0x51, 0x21, 0x5e}}, // Q 0x51
+    {{0x7f, 0x09, 0x19, 0x29, 0x46}}, // R 0x52
+    {{0x46, 0x49, 0x49, 0x49, 0x31}}, // S 0x53
+    {{0x01, 0x01, 0x7f, 0x01, 0x01}}, // T 0x54
+    {{0x3f, 0x40, 0x40, 0x40, 0x3f}}, // U 0x55
+    {{0x1f, 0x20, 0x40, 0x20, 0x1f}}, // V 0x56
+    {{0x3f, 0x40, 0x38, 0x40, 0x3f}}, // W 0x57
+    {{0x63, 0x14, 0x08, 0x14, 0x63}}, // X 0x58
+    {{0x07, 0x08, 0x70, 0x08, 0x07}}, // Y 0x59
+    {{0x61, 0x51, 0x49, 0x45, 0x43}}, // Z 0x5a
+    {{0x00, 0x7f, 0x41, 0x41, 0x00}}, // [ 0x5b
+    {{0x02, 0x04, 0x08, 0x10, 0x20}}, // \\ 0x5c
+    {{0x00, 0x41, 0x41, 0x7f, 0x00}}, // ] 0x5d
+    {{0x04, 0x02, 0x01, 0x02, 0x04}}, // ^ 0x5e
+    {{0x40, 0x40, 0x40, 0x40, 0x40}}, // _ 0x5f
+    {{0x00, 0x01, 0x02, 0x04, 0x00}}, // ` 0x60
+    {{0x20, 0x54, 0x54, 0x54, 0x78}}, // a 0x61
+    {{0x7f, 0x48, 0x44, 0x44, 0x38}}, // b 0x62
+    {{0x38, 0x44, 0x44, 0x44, 0x20}}, // c 0x63
+    {{0x38, 0x44, 0x44, 0x48, 0x7f}}, // d 0x64
+    {{0x38, 0x54, 0x54, 0x54, 0x18}}, // e 0x65
+    {{0x08, 0x7e, 0x09, 0x01, 0x02}}, // f 0x66
+    {{0x0c, 0x52, 0x52, 0x52, 0x3e}}, // g 0x67
+    {{0x7f, 0x08, 0x04, 0x04, 0x78}}, // h 0x68
+    {{0x00, 0x44, 0x7d, 0x40, 0x00}}, // i 0x69
+    {{0x20, 0x40, 0x44, 0x3d, 0x00}}, // j 0x6a
+    {{0x7f, 0x10, 0x28, 0x44, 0x00}}, // k 0x6b
+    {{0x00, 0x41, 0x7f, 0x40, 0x00}}, // l 0x6c
+    {{0x7c, 0x04, 0x18, 0x04, 0x78}}, // m 0x6d
+    {{0x7c, 0x08, 0x04, 0x04, 0x78}}, // n 0x6e
+    {{0x38, 0x44, 0x44, 0x44, 0x38}}, // o 0x6f
+    {{0x7c, 0x14, 0x14, 0x14, 0x08}}, // p 0x70
+    {{0x08, 0x14, 0x14, 0x18, 0x7c}}, // q 0x71
+    {{0x7c, 0x08, 0x04, 0x04, 0x08}}, // r 0x72
+    {{0x48, 0x54, 0x54, 0x54, 0x20}}, // s 0x73
+    {{0x04, 0x3f, 0x44, 0x40, 0x20}}, // t 0x74
+    {{0x3c, 0x40, 0x40, 0x20, 0x7c}}, // u 0x75
+    {{0x1c, 0x20, 0x40, 0x20, 0x1c}}, // v 0x76
+    {{0x3c, 0x40, 0x30, 0x40, 0x3c}}, // w 0x77
+    {{0x44, 0x28, 0x10, 0x28, 0x44}}, // x 0x78
+    {{0x0c, 0x50, 0x50, 0x50, 0x3c}}, // y 0x79
+    {{0x44, 0x64, 0x54, 0x4c, 0x44}}, // z 0x7a
+    {{0x00, 0x08, 0x36, 0x41, 0x00}}, // { 0x7b
+    {{0x00, 0x00, 0x7f, 0x00, 0x00}}, // | 0x7c
+    {{0x00, 0x41, 0x36, 0x08, 0x00}}, // } 0x7d
+    {{0x10, 0x08, 0x08, 0x10, 0x08}}, // ~ 0x7e
+};
+
+// utf8 characters list ending with empty struct
+const struct Utf8Symbol utf8_glyphs[] = {
+    { .symbol="�", {{0xFE, 0x82, 0x82, 0x82, 0xFE}} }, // box
+    { .symbol="×", {{0x22, 0x14, 0x08, 0x14, 0x22}} }, // cross
+    { .symbol="↑", {{0x08, 0x04, 0x3e, 0x04, 0x08}} }, // arrow_up
+    { .symbol="↓", {{0x08, 0x10, 0x3e, 0x10, 0x08}} }, // arrow_down
+    { .symbol="←", {{0x08, 0x1c, 0x2a, 0x08, 0x08}} }, // arrow_left
+    { .symbol="→", {{0x08, 0x08, 0x2a, 0x1c, 0x08}} }, // arrow_right
+    { .symbol="⏰", {{0x1c, 0x22, 0x2e, 0x2a, 0x1c}} }, // clock
+    { .symbol="⌛", {{0x63, 0x55, 0x4d, 0x55, 0x63}} }, // hourglass
+    { .symbol="☸", {{0x1c, 0x22, 0x2a, 0x22, 0x1c}} }, // wheel
+    { .symbol="⏎", {{0x10, 0x38, 0x54, 0x10, 0x1e}} }, // return
+    { .symbol="🌡", {{0x60, 0x9e, 0x81, 0x9e, 0x6a}} }, // thermometer
+    { .symbol="°", {{0x00, 0x07, 0x05, 0x07, 0x00}} }, // degree
+    { .symbol="🔙", {{0x04, 0x4e, 0x55, 0x44, 0x38}} }, // back
+    { .symbol="▶", {{0x7f, 0x3e, 0x1c, 0x08, 0x00}} }, // tri_right
+    { .symbol="◀", {{0x00, 0x08, 0x1c, 0x3e, 0x7f}} }, // tri_left
+
+    // End of the list
+    {},
+};
+
+const struct FontGraphic *Font_GetSymbol(struct Utf8Char ch) {
+    if (ch.bytes[0] < 32) {
+        // low ASCII is not supported.
+        goto fail;
+    }
+
+    if (ch.bytes[0] < 127) {
+        // valid ASCII at hard positions.
+        // In this case only the first byte is significant.
+        return &ascii_glyphs[ch.bytes[0] - 32];
+    }
+
+    // search UTF8
+    const struct Utf8Symbol *sym = &utf8_glyphs[0];
+    while (sym->symbol[0]) {
+        if (sym->uint == ch.uint) {
+            return &sym->graphic;
+        }
+        sym++;
+    }
+
+fail:
+    return &utf8_glyphs[0].graphic; // replacement character
+}

main/graphics/font.h

@@ -0,0 +1,20 @@
+/**
+ * UTF-8 capable bitmap font
+ * 
+ * Created on 2020/01/04.
+ */
+
+#ifndef GFX_FONT_H
+#define GFX_FONT_H
+
+#include "font.h"
+#include "utf8.h"
+#include <stdint.h>
+
+struct FontGraphic {
+    uint8_t columns[5];
+};
+
+const struct FontGraphic *Font_GetSymbol(struct Utf8Char ch);
+
+#endif //GFX_FONT_H

main/graphics/nokia.c

@@ -0,0 +1,178 @@
+#include <driver/gpio.h>
+#include <driver/spi_master.h>
+#include "nokia.h"
+#include <string.h>
+
+/* Pin definitions:
+Most of these pins can be moved to any digital or analog pin.
+DN(MOSI)and SCLK should be left where they are (SPI pins). The
+LED (backlight) pin should remain on a PWM-capable pin. */
+static const int scePin = 17;   // SCE - Chip select, pin 3 on LCD.
+static const int rstPin = 16;   // RST - Reset, pin 4 on LCD.
+static const int dcPin = 4;    // DC - Data/Command, pin 5 on LCD.
+static const int sdinPin = 15;  // DN(MOSI) - Serial data, pin 6 on LCD.
+static const int sclkPin = 13;  // SCLK - Serial clock, pin 7 on LCD.
+
+/* PCD8544-specific defines: */
+#define LCD_COMMAND  0
+#define LCD_DATA     1
+
+#define DEFAULT_CONTRAST 48
+
+static spi_device_handle_t hSPI;
+
+/* The displayMap variable stores a buffer representation of the
+pixels on our display. There are 504 total bits in this array,
+same as how many pixels there are on a 84 x 48 display.
+
+Each byte in this array covers a 8-pixel vertical block on the
+display. Each successive byte covers the next 8-pixel column over
+until you reach the right-edge of the display and step down 8 rows.
+
+To update the display, we first have to write to this array, then
+call the updateDisplay() function, which sends this whole array
+to the PCD8544.
+
+Because the PCD8544 won't let us write individual pixels at a
+time, this is how we can make targeted changes to the display. */
+uint8_t LCD_displayMap[LCD_WIDTH * LCD_HEIGHT / 8] = {};
+
+// There are two memory banks in the LCD, data/RAM and commands.
+// This function sets the DC pin high or low depending, and then
+// sends the data byte
+static void LCD_SendBytes(bool data_or_command, const uint8_t *data, size_t len)
+{
+    esp_err_t ret;
+    spi_transaction_t t;
+    if (len == 0) return;             //no need to send anything
+    memset(&t, 0, sizeof(t));       //Zero out the transaction
+    t.length = len * 8;                 //Len is in bytes, transaction length is in bits.
+    t.tx_buffer = data;               //Data
+    t.user = (void *) data_or_command;                //D/C
+    ret = spi_device_polling_transmit(hSPI, &t);  //Transmit!
+    assert(ret == ESP_OK);            //Should have had no issues.
+}
+
+// There are two memory banks in the LCD, data/RAM and commands.
+// This function sets the DC pin high or low depending, and then
+// sends the data byte
+static void LCD_SendByte(bool data_or_command, uint8_t data)
+{
+    esp_err_t ret;
+    spi_transaction_t t;
+    memset(&t, 0, sizeof(t));       //Zero out the transaction
+    t.length = 8;                 // transaction length is in bits.
+    t.tx_data[0] = data;               //Data
+    t.flags = SPI_TRANS_USE_TXDATA;
+    t.user = (void *) data_or_command;                //D/C
+    ret = spi_device_polling_transmit(hSPI, &t);  //Transmit!
+    assert(ret == ESP_OK);            //Should have had no issues.
+}
+
+
+// Helpful function to directly command the LCD to go to a
+// specific x,y coordinate.
+static void gotoXY(int x, int y)
+{
+    const uint8_t cmd[2] = {
+        0x80 | x,
+        0x40 | y,
+    };
+    LCD_SendBytes(LCD_COMMAND, cmd, 2);
+}
+
+// This will actually draw on the display, whatever is currently
+// in the displayMap array.
+void LCD_updateDisplay()
+{
+    spi_device_acquire_bus(hSPI, portMAX_DELAY);
+    gotoXY(0, 0);
+    LCD_SendBytes(LCD_DATA, &LCD_displayMap[0], LCD_WIDTH * (LCD_HEIGHT / 8));
+    spi_device_release_bus(hSPI);
+}
+
+// Set contrast can set the LCD Vop to a value between 0 and 127.
+// 40-60 is usually a pretty good range.
+void LCD_setContrast(uint8_t contrast)
+{
+    spi_device_acquire_bus(hSPI, portMAX_DELAY);
+    const uint8_t cmd[3] = {
+        0x21,  //Tell LCD that extended commands follow
+        0x80 | contrast,//Set LCD Vop (Contrast): Try 0xB1(good @ 3.3V) or 0xBF if your display is too dark
+        0x20,//Set display mode
+    };
+    LCD_SendBytes(LCD_COMMAND, cmd, 3);
+    spi_device_release_bus(hSPI);
+}
+
+void LCD_invertDisplay(bool invert)
+{
+    LCD_SendByte(LCD_COMMAND, 0x0C | invert);
+}
+
+//This function is called (in irq context!) just before a transmission starts. It will
+//set the D/C line to the value indicated in the user field.
+void lcd_spi_pre_transfer_callback(spi_transaction_t *t)
+{
+    int dc = (int) t->user;
+    gpio_set_level(dcPin, dc);
+}
+
+//This sends the magical commands to the PCD8544
+void LCD_setup(void)
+{
+    gpio_config_t output = {
+        .pin_bit_mask = (1 << scePin) | (1 << rstPin) | (1 << dcPin) | (1 << sdinPin) | (1 << sclkPin),
+        .mode = GPIO_MODE_OUTPUT
+    };
+    gpio_config(&output);
+
+    esp_err_t ret;
+    spi_bus_config_t buscfg = {
+        .miso_io_num=-1,
+        .mosi_io_num=sdinPin,
+        .sclk_io_num=sclkPin,
+        .quadwp_io_num=-1,
+        .quadhd_io_num=-1,
+        .max_transfer_sz=LCD_WIDTH * LCD_HEIGHT, // ??? this doesnt seem to do anything in the driver
+    };
+    spi_device_interface_config_t devcfg = {
+        .clock_speed_hz=4 * 1000 * 1000, // Hz
+        // enable signal lead/lag
+        .cs_ena_pretrans = 0,
+        .cs_ena_posttrans = 0,
+        .mode=0,                            //SPI mode 0
+        .spics_io_num=scePin,               //CS pin
+        .queue_size=1, // we use the polling mode, so this does not matter
+        .pre_cb=lcd_spi_pre_transfer_callback,  //Specify pre-transfer callback to handle D/C line
+    };
+
+    //Initialize the SPI bus
+    ret = spi_bus_initialize(HSPI_HOST, &buscfg, 1);
+    ESP_ERROR_CHECK(ret);
+    //Attach the LCD to the SPI bus
+    ret = spi_bus_add_device(HSPI_HOST, &devcfg, &hSPI);
+    ESP_ERROR_CHECK(ret);
+
+    spi_device_acquire_bus(hSPI, portMAX_DELAY);
+    {
+        //Reset the LCD to a known state
+        gpio_set_level(rstPin, 0);
+        gpio_set_level(rstPin, 1);
+
+        const uint8_t magic[6] = {
+            0x21, // Tell LCD extended commands follow
+            0x80 + DEFAULT_CONTRAST, // Set LCD Vop (Contrast)
+            0x04, // Set Temp coefficent
+            0x14, // LCD bias mode 1:48 (try 0x13)
+            //We must send 0x20 before modifying the display control mode
+            0x20, // Clear extended option
+            0x0C, // Set display control, normal mode.
+        };
+        LCD_SendBytes(LCD_COMMAND, &magic[0], 6);
+    }
+    spi_device_release_bus(hSPI);
+
+    // show the blank screen (display is in an undefined state after boot)
+    LCD_updateDisplay();
+}

main/graphics/nokia.h

@@ -0,0 +1,39 @@
+/**
+ * Driver for Nokia 5110 SPI LCD display
+ */
+
+#ifndef GFX_NOKIA_H
+#define GFX_NOKIA_H
+
+/* Pin definitions:
+Most of these pins can be moved to any digital or analog pin.
+DN(MOSI)and SCLK should be left where they are (SPI pins). The
+LED (backlight) pin should remain on a PWM-capable pin. */
+// SCE - Chip select, pin 3 on LCD.
+// RST - Reset, pin 4 on LCD.
+// DC - Data/Command, pin 5 on LCD.
+// DN(MOSI) - Serial data, pin 6 on LCD.
+// SCLK - Serial clock, pin 7 on LCD.
+// LED - Backlight LED, pin 8 on LCD.
+
+/* 84x48 LCD Defines: */
+#include <stdbool.h>
+#include <stdint.h>
+#include "utf8.h"
+#include "display_spec.h"
+
+// This will actually draw on the display, whatever is currently
+// in the displayMap array.
+void LCD_updateDisplay();
+
+// Set contrast can set the LCD Vop to a value between 0 and 127.
+// 40-60 is usually a pretty good range.
+void LCD_setContrast(uint8_t contrast);
+
+/* Invert colors */
+void LCD_invertDisplay(bool invert);
+
+//This sends the magical commands to the PCD8544
+void LCD_setup(void);
+
+#endif // GFX_NOKIA_H

main/graphics/utf8.c

@@ -0,0 +1,122 @@
+#include <stdint.h>
+#include "utf8.h"
+
+//
+// Created by MightyPork on 2017/08/20.
+//
+// UTF-8 parser - collects bytes of a code point before writing them
+// into a screen cell.
+//
+
+const struct Utf8Char EMPTY_CHAR = (struct Utf8Char) {.uint = 0};
+
+//      Code Points      First Byte Second Byte Third Byte Fourth Byte
+//  U+0000 -   U+007F     00 - 7F
+//  U+0080 -   U+07FF     C2 - DF    80 - BF
+//	U+0800 -   U+0FFF     E0         *A0 - BF     80 - BF
+//	U+1000 -   U+CFFF     E1 - EC    80 - BF     80 - BF
+//	U+D000 -   U+D7FF     ED         80 - *9F     80 - BF
+//	U+E000 -   U+FFFF     EE - EF    80 - BF     80 - BF
+//	U+10000 -  U+3FFFF    F0         *90 - BF     80 - BF    80 - BF
+//	U+40000 -  U+FFFFF    F1 - F3    80 - BF     80 - BF    80 - BF
+//	U+100000 - U+10FFFF   F4         80 - *8F     80 - BF    80 - BF
+
+size_t utf8_strlen(const char *text)
+{
+    // TODO optimize
+    struct Utf8Iterator iter;
+    Utf8Iterator_Init(&iter, text);
+    size_t num = 0;
+    while ((Utf8Iterator_Next(&iter)).uint) {
+        num++;
+    }
+    return num;
+}
+
+/**
+ * Handle a received character
+ */
+struct Utf8Char Utf8Parser_Handle(struct Utf8Parser *self, char c)
+{
+    uint8_t *bytes = self->buffer.bytes;
+
+    uint8_t uc = (uint8_t) c;
+    // collecting unicode glyphs...
+    if (uc & 0x80) {
+        if (self->utf_len == 0) {
+            bytes[0] = uc;
+            self->utf_j = 1;
+
+            // start
+            if (uc == 0xC0 || uc == 0xC1 || uc > 0xF4) {
+                // forbidden start codes
+                goto fail;
+            }
+
+            if ((uc & 0xE0) == 0xC0) {
+                self->utf_len = 2;
+            }
+            else if ((uc & 0xF0) == 0xE0) {
+                self->utf_len = 3;
+            }
+            else if ((uc & 0xF8) == 0xF0) {
+                self->utf_len = 4;
+            }
+            else {
+                // chars over 127 that don't start unicode sequences
+                goto fail;
+            }
+        }
+        else {
+            if ((uc & 0xC0) != 0x80) {
+                bytes[self->utf_j++] = uc;
+                goto fail;
+            }
+            else {
+                bytes[self->utf_j++] = uc;
+                if (self->utf_j >= self->utf_len) {
+                    // check for bad sequences - overlong or some other problem
+                    if (bytes[0] == 0xF4 && bytes[1] > 0x8F) goto fail;
+                    if (bytes[0] == 0xF0 && bytes[1] < 0x90) goto fail;
+                    if (bytes[0] == 0xED && bytes[1] > 0x9F) goto fail;
+                    if (bytes[0] == 0xE0 && bytes[1] < 0xA0) goto fail;
+
+                    // trap for surrogates - those break javascript
+                    if (bytes[0] == 0xED && bytes[1] >= 0xA0 && bytes[1] <= 0xBF) goto fail;
+
+                    goto success;
+                }
+            }
+        }
+    }
+    else {
+        bytes[0] = uc;
+        goto success;
+    }
+
+    return EMPTY_CHAR;
+
+success:;
+    struct Utf8Char result = self->buffer;
+    self->buffer.uint = 0; // erase the buffer
+    self->utf_len = 0;
+    return result;
+
+fail:
+    self->buffer.uint = 0; // erase the buffer
+    self->utf_len = 0;
+    return EMPTY_CHAR;
+}
+
+struct Utf8Char Utf8Iterator_Next(struct Utf8Iterator *self)
+{
+    char c;
+    struct Utf8Char uchar;
+    while ((c = *self->source++) != 0) {
+        uchar = Utf8Parser_Handle(&self->parser, c);
+        if (uchar.uint) {
+            return uchar;
+        }
+    }
+    return EMPTY_CHAR;
+}

main/graphics/utf8.h

@@ -0,0 +1,84 @@
+/**
+ * UTF-8 string parsing and character iteration
+ * 
+ * Created on 2020/01/04.
+ */
+
+#ifndef LIQUIDTYPE_UTF8_H
+#define LIQUIDTYPE_UTF8_H
+
+#include <stddef.h>
+#include <stdint.h>
+
+/**
+ * UTF-8 encoded character.
+ */
+struct Utf8Char {
+    union {
+        /** character bytes; padded by zero bytes if shorter than 4 */
+        uint8_t bytes[4];
+        /** u32 view of the bytes */
+        uint32_t uint;
+    };
+};
+
+/** UTF8 string parser internal state */
+struct Utf8Parser {
+    /** UTF-8 bytes buffer */
+    struct Utf8Char buffer;
+    /** Currently collected UTF-8 character length */
+    uint8_t utf_len;
+    /** Position in the current character */
+    uint8_t utf_j;
+};
+
+static inline void Utf8Parser_Clear(struct Utf8Parser *self) {
+    self->buffer.uint = 0;
+    self->utf_j = 0;
+    self->utf_len = 0;
+}
+
+/**
+ * Utf8 character iterator.
+ *
+ * Usage:
+ * struct Utf8Iterator iter;
+ * Utf8Iterator_Init(&iter, myString);
+ *
+ * union Utf8Char uchar;
+ * while ((uchar = Utf8Iterator_Next(&iter)).uint) {
+ *     // do something with the char
+ * }
+ *
+ * // Free myString if needed, it is not mutated.
+ */
+struct Utf8Iterator {
+    /* Characters to parse. The pointer is advanced as the iterator progresses. */
+    const char *source;
+    struct Utf8Parser parser;
+};
+
+static inline void Utf8Iterator_Init(struct Utf8Iterator *self, const char *source) {
+    Utf8Parser_Clear(&self->parser);
+    self->source = source;
+}
+
+size_t utf8_strlen(const char *text);
+
+/**
+ * Get the next character from the iterator; Returns empty character if there are no more characters to parse.
+ *
+ * Invalid characters are skipped.
+ */
+struct Utf8Char Utf8Iterator_Next(struct Utf8Iterator *self);
+
+/**
+ * Parse a character.
+ *
+ * The returned struct contains NIL (uint == 0) if no character is yet available.
+ *
+ * ASCII is passed through, utf-8 is collected and returned in one piece.
+ */
+struct Utf8Char Utf8Parser_Handle(struct Utf8Parser *self, char c);
+
+#endif //LIQUIDTYPE_UTF8_H

main/liquid/gui.c

@@ -1,44 +1,21 @@
-#include "gui.h"
-#include "nokia.h"
-#include "analog.h"
 #include <freertos/FreeRTOS.h>
 #include <freertos/task.h>
-#include <liquid.h>
+
-#include <freertos/timers.h>
+#include "nokia.h"
+#include "liquid.h"
+#include "drawing.h"
 
 static void gui_thread(void *arg);
-static void gui_tick(TimerHandle_t xTimer);
 
 TaskHandle_t hGuiThread = NULL;
-TimerHandle_t hTicker = NULL;
-
 
 void gui_init() {
     printf("GUI init\n");
     LCD_setup();
-
+    LCD_setContrast(57);
-    LCD_setContrast(60);
-
-    LCD_clearDisplay(0);
-    LCD_setStr("Hello World", 0, 0, 1);
-    LCD_updateDisplay();
 
     int rv = xTaskCreate(gui_thread, "gui", 4096, NULL, 6, &hGuiThread);
     assert (rv == pdPASS);
-
-    hTicker = xTimerCreate(
-        "gui_tick", /* name */
-        pdMS_TO_TICKS(10), /* period/time */
-        pdTRUE, /* auto reload */
-        (void*)0, /* timer ID */
-        gui_tick); /* callback */
-    assert(hTicker != NULL);
-
-    xTimerStart(hTicker, portMAX_DELAY);
-}
-
-static void gui_tick(TimerHandle_t xTimer) {
-    xTaskNotify(hGuiThread, 0b10000, eSetBits);
 }
 
 /**
@@ -48,7 +25,6 @@ static void gui_tick(TimerHandle_t xTimer) {
  *    0b10 - knowb CCW
  *   0b100 - button released
  *  0b1000 - button pressed
- * 0b10000 - ticker event
  *
  * @param arg
  */
@@ -57,17 +33,16 @@ static void __attribute__((noreturn)) gui_thread(void *arg) {
 
     uint32_t last_wheel_time = 0;
 
+    uint32_t last_time = xTaskGetTickCount();
     while (1) {
+        bool want_repaint = false;
         uint32_t value = 0;
         xTaskNotifyWait(0, ULONG_MAX, &value, pdMS_TO_TICKS(10));
+        uint32_t time = xTaskGetTickCount();
 
-        bool want_repaint = false;
+        if (time - last_time >= pdMS_TO_TICKS(2)) {
-
+            want_repaint |= Liquid_handleTick(liquid, time - last_time);
-//        printf("Knob event 0x%02x  ", value);
+            last_time = time;
-
-        if (value & 0b10000) {
-            // TICK
-            want_repaint |= Liquid_handleTick(liquid);
         }
 
         if (value & 0b1000) {
@@ -77,8 +52,8 @@ static void __attribute__((noreturn)) gui_thread(void *arg) {
         }
 
         if (value & 0b11) {
-            uint32_t time = xTaskGetTickCount();
             uint32_t increment = 1;
+            // wheel delta changes with speed
             if (last_wheel_time != 0) {
                 uint32_t ela = time - last_wheel_time;
                 if (ela < pdMS_TO_TICKS(20)) {

main/liquid/input_event.h

@@ -0,0 +1,57 @@
+/**
+ * Input event structural enum
+ * 
+ * Created on 2020/01/05.
+ */
+
+#ifndef LIQUID_INPUT_EVENT_H
+#define LIQUID_INPUT_EVENT_H
+
+#include <stdint.h>
+
+enum InputEvent_Kind {
+    InputEventKind_Wheel,
+    InputEventKind_Button,
+};
+
+struct InputEvent {
+    enum InputEvent_Kind kind;
+    union {
+        struct {
+            // Wheel delta
+            int32_t delta;
+            int8_t direction;
+        } wheel;
+        struct {
+            // Button state
+            bool state;
+        } button;
+    };
+};
+
+static inline struct InputEvent InputEvent_Wheel(int32_t delta)
+{
+    return (struct InputEvent) {
+        .kind = InputEventKind_Wheel,
+        .wheel = {
+            .delta = delta,
+            .direction = delta > 0 ? 1 : -1,
+        }
+    };
+}
+
+/**
+ * Button event (push, release)
+ *
+ * @param state - pushed
+ * @return event
+ */
+static inline struct InputEvent InputEvent_Button(bool state)
+{
+    return (struct InputEvent) {
+        .kind = InputEventKind_Button,
+        .button = {.state = state},
+    };
+}
+
+#endif //LIQUID_INPUT_EVENT_H

main/liquid/liquid.c

@@ -1,12 +1,17 @@
-#include "liquid.h"
-#include "rom/queue.h"
-#include "scenes.h"
 #include <malloc.h>
 #include <assert.h>
 #include <esp_log.h>
+#include <rom/queue.h>
+
+#include "liquid.h"
+#include "nokia.h"
 
 static const char *TAG = "Liquid";
 
+extern struct Scene *NewScene_Root(void);
+static struct SceneEvent Liquid_initTopScene(struct Liquid *container);
+static bool processReturnValue(struct Liquid *container, struct SceneEvent result);
+
 struct RunningScene {
     struct Scene *scene;
     SLIST_ENTRY(RunningScene) next;
@@ -16,7 +21,7 @@ struct Liquid {
     SLIST_HEAD(, RunningScene) stack; // stack with the topmost scene as the first element / head
 };
 
-static struct SceneEvent Default_onChildReturn(struct Scene *scene, uint32_t tag, uint32_t status, void *data) {
+static struct SceneEvent Default_onChildReturn(struct Scene *scene, uint32_t tag, int32_t status, void *data) {
     if (data) free(data);
     return SceneEvent_Repaint();
 }
@@ -24,29 +29,35 @@ static struct SceneEvent Default_onChildReturn(struct Scene *scene, uint32_t tag
 static void addChild(struct Liquid *container, struct Scene *child) {
     struct RunningScene *elm = calloc(1, sizeof(struct RunningScene));
     if (!child->onChildReturn) child->onChildReturn = Default_onChildReturn;
-    assert(child->paint != NULL);
     elm->scene = child;
     SLIST_INSERT_HEAD(&container->stack, elm, next);
 }
 
-struct Liquid *Liquid_start() {
+struct Liquid *Liquid_start(void) {
     struct Liquid *container = calloc(1, sizeof(struct Liquid));
 
     addChild(container, NewScene_Root());
-    Liquid_paint(container);
+
+    struct SceneEvent result = Liquid_initTopScene(container);
+
+    if (processReturnValue(container, result)) {
+        Liquid_paint(container);
+    }
     return container;
 }
 
 static struct SceneEvent handleSceneEvent(struct Liquid *container, struct SceneEvent event) {
     struct RunningScene *topmost = SLIST_FIRST(&container->stack);
+    struct Scene *newScene;
+    uint32_t tag;
     switch (event.kind) {
         case SceneEventKind_Close:
             assert(SLIST_NEXT(topmost, next) != NULL);
             SLIST_REMOVE_HEAD(&container->stack, next);
-            uint32_t tag = topmost->scene->tag;
+            tag = topmost->scene->tag;
 
-            if (topmost->scene->options) {
+            if (topmost->scene->deinit) {
-                free(topmost->scene->options);
+                topmost->scene->deinit(topmost->scene);
             }
             free(topmost->scene);
             free(topmost);
@@ -56,15 +67,15 @@ static struct SceneEvent handleSceneEvent(struct Liquid *container, struct Scene
             // this is always set.
             return topmost->scene->onChildReturn(topmost->scene, tag, event.close.status, event.close.data);
 
-        case SceneEventKind_OpenChild:;
+        case SceneEventKind_OpenChild:
             if (!event.open.scene) {
                 ESP_LOGE(TAG, "Attempt to open NULL scene!");
                 return SceneEvent_None();
             }
-            struct Scene *newScene = event.open.scene;
+            newScene = event.open.scene;
             newScene->tag = event.open.tag;
             addChild(container, newScene);
-            return SceneEvent_Repaint();
+            return Liquid_initTopScene(container);
 
         case SceneEventKind_RequestRepaint:
         case SceneEventKind_None:
@@ -74,14 +85,26 @@ static struct SceneEvent handleSceneEvent(struct Liquid *container, struct Scene
     }
 }
 
-bool processReturnValue(struct Liquid *container, struct SceneEvent result) {
+/**
+ * returns true if repaint is requested
+ */
+static bool processReturnValue(struct Liquid *container, struct SceneEvent result) {
+    bool repaint = false;
     while (result.kind != SceneEventKind_None) {
         if (result.kind == SceneEventKind_RequestRepaint) {
-            return 1; // repaint
+            // Repaint explicitly requested, there's no more chained events.
+            repaint = true;
+            break;
         }
+        if (result.kind == SceneEventKind_Close) {
+            // child close always triggers repaint, but the event handler can return
+            // another event (e.g. close itself, or open a new child).
+            repaint = true;
+        }
+        // one event can lead to another...
         result = handleSceneEvent(container, result);
     }
-    return 0;
+    return repaint;
 }
 
 bool Liquid_handleInput(struct Liquid *container, struct InputEvent event) {
@@ -96,20 +119,35 @@ bool Liquid_handleInput(struct Liquid *container, struct InputEvent event) {
     }
 }
 
-bool Liquid_handleTick(struct Liquid *container) {
+bool Liquid_handleTick(struct Liquid *container, uint32_t elapsed_millis) {
     struct RunningScene *topmost = SLIST_FIRST(&container->stack);
     assert(topmost != NULL);
     assert(topmost->scene != NULL);
     if (topmost->scene->onTick) {
-        struct SceneEvent result = topmost->scene->onTick(topmost->scene);
+        struct SceneEvent result = topmost->scene->onTick(topmost->scene, elapsed_millis);
         return processReturnValue(container, result);
     } else {
         return false;
     }
 }
 
+static struct SceneEvent Liquid_initTopScene(struct Liquid *container) {
+    struct RunningScene *topmost = SLIST_FIRST(&container->stack);
+    assert(topmost != NULL);
+    assert(topmost->scene != NULL);
+    if (topmost->scene->init) {
+        return topmost->scene->init(topmost->scene);
+    } else {
+        return SceneEvent_Repaint();
+    }
+}
+
 void Liquid_paint(struct Liquid *container) {
     struct RunningScene *topmost = SLIST_FIRST(&container->stack);
     assert(topmost != NULL);
-    topmost->scene->paint(topmost->scene);
+    if (topmost->scene->paint) {
+        topmost->scene->paint(topmost->scene);
+    }
+
+    LCD_updateDisplay();
 }

main/liquid/liquid.h

@@ -4,134 +4,27 @@
  * Created on 2020/01/03.
  */
 
-#ifndef REFLOWER_LIQUID_H
+#ifndef LIQUID_H
-#define REFLOWER_LIQUID_H
+#define LIQUID_H
 
 #include <stdint.h>
 #include <stdbool.h>
+#include "input_event.h"
+#include "scene_event.h"
+#include "scene_type.h"
 
 struct Liquid;
 
-enum InputEvent_Kind {
-    InputEventKind_Wheel,
-    InputEventKind_Button,
-};
-
-struct InputEvent {
-    enum InputEvent_Kind kind;
-    union {
-        struct {
-            // Wheel delta
-            int8_t delta;
-        } wheel;
-        struct {
-            // Button state
-            bool state;
-        } button;
-    };
-};
-
-#define InputEvent_Wheel(delta_) ((struct InputEvent) { \
-    .kind = InputEventKind_Wheel, \
-    .wheel = { .delta = delta_ } \
-})
-
-#define InputEvent_Button(state_) ((struct InputEvent) { \
-    .kind = InputEventKind_Button, \
-    .button = { .state = state_ }, \
-})
-
-enum SceneEvent_Kind {
-    // Close this scene.
-    // The scene is responsible for cleaning up 'private'.
-    // 'options' and the scene itself will be freed by the GUI engine.
-    SceneEventKind_Close,
-    SceneEventKind_OpenChild,
-    SceneEventKind_RequestRepaint,
-    SceneEventKind_None,
-};
-
-struct SceneEvent {
-    enum SceneEvent_Kind kind;
-    union {
-        struct {
-            // Status code
-            uint32_t status;
-            // Return data on heap
-            void *data;
-        } close;
-        struct {
-            // Scene (initialized, with options loaded in through the constructor)
-            void *scene;
-            // Tag used by parent to identify the open child
-            uint32_t tag;
-        } open;
-    };
-};
-
-struct Scene;
-
-#define SceneEvent_None() ((struct SceneEvent) { \
-    .kind = SceneEventKind_None\
-})
-
-#define SceneEvent_Repaint() ((struct SceneEvent) { \
-    .kind = SceneEventKind_RequestRepaint\
-})
-
-#define SceneEvent_OpenChild(child_, tag_) ((struct SceneEvent) { \
-    .kind = SceneEventKind_OpenChild,\
-    .open = { .scene = (child_), .tag=tag_ }, \
-})
-
-#define SceneEvent_Close(status_, data_) ((struct SceneEvent) { \
-    .kind = SceneEventKind_Close,\
-    .close = { .status = (status_), .data=(data_) }, \
-})
-
-typedef struct SceneEvent (*Scene_onInput_t)(struct Scene *scene, struct InputEvent event);
-typedef struct SceneEvent (*Scene_onChildReturn_t)(struct Scene *scene, uint32_t tag, uint32_t status, void *data);
-typedef struct SceneEvent (*Scene_onTick_t)(struct Scene *scene);
-typedef void (*Scene_repaint_t)(struct Scene *scene);
-
-struct Scene {
-    uint32_t tag;
-    void *options;
-    void *private;
-    /** Handle input */
-    Scene_onInput_t onInput;
-    /** Handle child scene return */
-    Scene_onChildReturn_t onChildReturn;
-    /** Periodic tick */
-    Scene_onTick_t onTick;
-    /** Periodic tick */
-    Scene_repaint_t paint;
-};
-
-/**
- * Allocate scene and the inner private type.
- *
- * Requires <malloc.h>
- *
- * Must be used like:
- *
- * struct Scene *scene = SCENE_SAFE_ALLOC(struct private);
- * scene->onInput = ...
- * return scene;
- */
-#define SCENE_SAFE_ALLOC(private_type) \
-    calloc(1, sizeof(struct Scene)); \
-    if (!scene) return NULL; \
-    scene->private = calloc(1, sizeof(private_type)); \
-    if (!scene->private) return NULL;
-
 /** return 1 if repaint requested */
 bool Liquid_handleInput(struct Liquid *container, struct InputEvent event);
 
 /** return 1 if repaint requested */
-bool Liquid_handleTick(struct Liquid *container);
+bool Liquid_handleTick(struct Liquid *container, uint32_t elapsed_millis);
 
+/** render the active scene */
 void Liquid_paint(struct Liquid *container);
-struct Liquid *Liquid_start();
 
-#endif //REFLOWER_LIQUID_H
+/** Initialize the GUI system with a root scene */
+struct Liquid *Liquid_start(void);
+
+#endif //LIQUID_H

main/liquid/scene_car.c

@@ -1,44 +0,0 @@
-#include "scenes.h"
-#include "liquid.h"
-#include "../nokia.h"
-#include <malloc.h>
-
-struct private {
-    int32_t pos;
-};
-
-static struct SceneEvent Car_onInput(struct Scene *scene, struct InputEvent event) {
-    struct private *priv = scene->private;
-    switch (event.kind) {
-        case InputEventKind_Wheel:
-            priv->pos += event.wheel.delta;
-            if (priv->pos < 0) priv->pos = 0;
-            if (priv->pos > LCD_WIDTH-21) priv->pos = LCD_WIDTH-21;
-            return SceneEvent_Repaint();
-
-        case InputEventKind_Button:
-            if (event.button.state) {
-                return SceneEvent_Close(0, NULL);
-            }
-            // fall through
-        default:
-            return SceneEvent_None();
-    }
-}
-
-static void Car_paint(struct Scene *scene)
-{
-    struct private *priv = scene->private;
-
-    LCD_clearDisplay(0);
-    LCD_setRect(priv->pos, LCD_HEIGHT/2-10, priv->pos+20,LCD_HEIGHT/2+10,0,1);
-    LCD_updateDisplay();
-}
-
-struct Scene *NewScene_Car(void) {
-    struct Scene *scene = SCENE_SAFE_ALLOC(struct private);
-
-    scene->onInput = Car_onInput;
-    scene->paint = Car_paint;
-    return scene;
-}

main/liquid/scene_event.h

@@ -0,0 +1,99 @@
+/**
+ * Scene event structural enum
+ * 
+ * Created on 2020/01/05.
+ */
+
+#ifndef LIQUID_SCENE_EVENT_H
+#define LIQUID_SCENE_EVENT_H
+
+// forward declaration
+struct Scene;
+
+enum SceneEvent_Kind {
+    SceneEventKind_Close,
+    SceneEventKind_OpenChild,
+    SceneEventKind_RequestRepaint,
+    SceneEventKind_None,
+};
+
+/**
+ * Scene event, returned from some scene methods.
+ *
+ * Use the constructor functions to create this struct.
+ */
+struct SceneEvent {
+    /** Event kind enum */
+    enum SceneEvent_Kind kind;
+    union {
+        /* data for Close event kind */
+        struct {
+            // Status code
+            int32_t status;
+            // Return data on heap
+            void *data;
+        } close;
+        /* Data for Open event kind */
+        struct {
+            // Scene (initialized, with options loaded in through the constructor)
+            struct Scene *scene;
+            // Tag used by parent to identify the open child
+            uint32_t tag;
+        } open;
+    };
+};
+
+/**
+ * Create empty (null object) scene event.
+ *
+ * @return event
+ */
+static inline struct SceneEvent SceneEvent_None(void)
+{
+    return (struct SceneEvent) {
+        .kind = SceneEventKind_None,
+    };
+}
+
+/**
+ * Request scene repaint
+ *
+ * @return event
+ */
+static inline struct SceneEvent SceneEvent_Repaint(void)
+{
+    return (struct SceneEvent) {
+        .kind = SceneEventKind_RequestRepaint
+    };
+}
+
+/**
+ * Request a sub-scene to be opened
+ *
+ * @param child - child scene
+ * @param tag - scene tag
+ * @return event
+ */
+static inline struct SceneEvent SceneEvent_OpenChild(struct Scene *child, uint32_t tag) {
+    return (struct SceneEvent) {
+        .kind = SceneEventKind_OpenChild,
+        .open = { .scene = child, .tag=tag },
+    };
+}
+
+/**
+ * Close this scene, returning to parent.
+ *
+ * @param status - status number for the parent
+ * @param data - heap-allocated data for parent, can be NULL; e.g. user input as string.
+ * @return event
+ */
+static inline struct SceneEvent SceneEvent_Close(int32_t status, void *data)
+{
+    return (struct SceneEvent) {
+        .kind = SceneEventKind_Close,
+        .close = {.status = status, .data=data},
+    };
+}
+
+#endif //LIQUID_SCENE_EVENT_H

main/liquid/scene_root.c

@@ -1,85 +0,0 @@
-#include "scenes.h"
-#include "liquid.h"
-#include "../nokia.h"
-#include "../analog.h"
-#include <malloc.h>
-#include <stdio.h>
-
-struct private {
-    int32_t pos;
-    uint32_t timer_phase;
-    uint32_t timer_prescale;
-};
-
-static struct SceneEvent Root_onInput(struct Scene *scene, struct InputEvent event) {
-    struct private *priv = scene->private;
-    switch (event.kind) {
-        case InputEventKind_Wheel:
-            priv->pos += event.wheel.delta;
-            break;
-
-        case InputEventKind_Button:
-            if (event.button.state) {
-                return SceneEvent_OpenChild(NewScene_Car(), 0);
-            }
-            break;
-    }
-
-    return SceneEvent_Repaint();
-}
-
-static struct SceneEvent Root_onTick(struct Scene *scene) {
-    struct private *priv = scene->private;
-    priv->timer_prescale += 1;
-
-    if (priv->timer_prescale == 100) {
-        priv->timer_prescale = 0;
-        priv->timer_phase += 1;
-        priv->timer_phase = priv->timer_phase & 0b11; // 0..3
-
-        return SceneEvent_Repaint();
-    }
-
-    return SceneEvent_None();
-}
-
-static void Root_paint(struct Scene *scene)
-{
-    struct private *priv = scene->private;
-
-    LCD_clearDisplay(0);
-    const char *header = "???";
-    switch (priv->timer_phase) {
-        case 0:
-            header = "ICE";
-            break;
-        case 1:
-            header = " COLD";
-            break;
-        case 2:
-            header = "COCA";
-            break;
-        case 3:
-            header = " COLA";
-            break;
-    }
-
-    LCD_setStr(header, 20, 3, 1);
-
-    LCD_setRect(0, 15, 83, 35, 1, 1);
-    char buf[10];
-    sprintf(buf, "%3d", priv->pos);
-    LCD_setStr(buf, 2, 17, 0);
-    sprintf(buf, "%.0f C", analog_read());
-    LCD_setStr(buf, 2, 26, 0);
-    LCD_updateDisplay();
-}
-
-struct Scene *NewScene_Root(void) {
-    struct Scene *scene = SCENE_SAFE_ALLOC(struct private);
-
-    scene->onInput = Root_onInput;
-    scene->paint = Root_paint;
-    scene->onTick = Root_onTick;
-    return scene;
-}

main/liquid/scene_type.h

@@ -0,0 +1,118 @@
+/**
+ * Scene struct
+ * 
+ * Created on 2020/01/05.
+ */
+
+#ifndef LIQUID_SCENE_TYPE_H
+#define LIQUID_SCENE_TYPE_H
+
+#include <stdint.h>
+
+struct Scene;
+struct InputEvent;
+
+/**
+ * Scene::onInput fp type - handle user input
+ *
+ * @param scene - self
+ * @param event - the input event
+ * @return follow-up scene event, can be SceneEvent_None() if not used.
+ */
+typedef struct SceneEvent (*Scene_onInput_t)(struct Scene *scene, struct InputEvent event);
+
+/**
+ * Scene::onChildReturn fp type
+ *
+ * @param scene - self
+ * @param tag - child's tag
+ * @param status - status code returned from the child
+ * @param data - data returned from the child, must be heap-allocated if not NULL.
+ * @return follow-up scene event, can be SceneEvent_None() if not used.
+ */
+typedef struct SceneEvent (*Scene_onChildReturn_t)(struct Scene *scene, uint32_t tag, int32_t status, void *data);
+
+/**
+ * Scene::onTick fp type
+ *
+ * @param scene - self
+ * @return follow-up scene event, can be SceneEvent_None() if not used.
+ */
+typedef struct SceneEvent (*Scene_onTick_t)(struct Scene *scene, uint32_t millis);
+
+/**
+ * Scene::init fp type
+ *
+ * @param scene - self
+ * @return follow-up scene event, can be SceneEvent_None() if not used.
+ */
+typedef struct SceneEvent (*Scene_init_t)(struct Scene *scene);
+
+/**
+ * Scene::paint fp type
+ *
+ * @param scene - self
+ */
+typedef void (*Scene_paint_t)(struct Scene *scene);
+
+/**
+ * Scene::deinit fp type.
+ * Release internally allocated resources.
+ * This is called by the GUI engine when the scene is closed.
+ *
+ * @param scene - self
+ */
+typedef void (*Scene_deinit_t)(struct Scene *scene);
+
+/**
+ * Scene instance in the framework
+ */
+struct Scene {
+    /**
+     * Tag given to the scene by its parent to identify its close event.
+     */
+    uint32_t tag;
+
+    /**
+     * Init function, called once after the scene has been opened.
+     * Nullable field.
+     */
+    Scene_init_t init;
+
+    /**
+     * Handle input event.
+     * Can return a follow-up scene event, e.g. repaint request.
+     * Nullable field.
+     */
+    Scene_onInput_t onInput;
+
+    /**
+     * Child scene closed, handle its return value and data, if any.
+     * Can return a follow-up scene event.
+     * In any case, the scene will be re-painted, if it stays open and on top.
+     * Nullable field.
+     */
+    Scene_onChildReturn_t onChildReturn;
+
+    /**
+     * Handle a periodic tick (10ms).
+     * Can return a follow-up scene event, e.g. repaint request.
+     * Nullable field.
+     */
+    Scene_onTick_t onTick;
+
+    /**
+     * Draw the scene to the LCD buffer.
+     * DO NOT write to the display yet, it will be done by the GUI engine.
+     * Nullable field.
+     */
+    Scene_paint_t paint;
+
+    /**
+     * Release internally allocated resources, if any. Called on close.
+     * Nullable field.
+     */
+    Scene_deinit_t deinit;
+};
+
+#endif //LIQUID_SCENE_TYPE_H

main/liquid/scenes.h

@@ -1,13 +0,0 @@
-/**
- * TODO file description
- * 
- * Created on 2020/01/03.
- */
-
-#ifndef REFLOWER_SCENES_H
-#define REFLOWER_SCENES_H
-
-struct Scene *NewScene_Root(void);
-struct Scene *NewScene_Car(void);
-
-#endif //REFLOWER_SCENES_H

main/nokia.c

@@ -1,509 +0,0 @@
-#include <driver/gpio.h>
-#include <arch/cc.h>
-#include <driver/spi_master.h>
-#include "nokia.h"
-#include <string.h>
-
-/* Pin definitions:
-Most of these pins can be moved to any digital or analog pin.
-DN(MOSI)and SCLK should be left where they are (SPI pins). The
-LED (backlight) pin should remain on a PWM-capable pin. */
-static const int scePin = 17;   // SCE - Chip select, pin 3 on LCD.
-static const int rstPin = 16;   // RST - Reset, pin 4 on LCD.
-static const int dcPin = 4;    // DC - Data/Command, pin 5 on LCD.
-static const int sdinPin = 15;  // DN(MOSI) - Serial data, pin 6 on LCD.
-static const int sclkPin = 13;  // SCLK - Serial clock, pin 7 on LCD.
-
-/* PCD8544-specific defines: */
-#define LCD_COMMAND  0
-#define LCD_DATA     1
-
-#define DEFAULT_CONTRAST 48
-
-static spi_device_handle_t hSPI;
-
-/* Font table:
-This table contains the hex values that represent pixels for a
-font that is 5 pixels wide and 8 pixels high. Each byte in a row
-represents one, 8-pixel, vertical column of a character. 5 bytes
-per character. */
-static const uint8_t ASCII[][5] = {
-    // First 32 characters (0x00-0x19) are ignored. These are
-    // non-displayable, control characters.
-    {0x00, 0x00, 0x00, 0x00, 0x00}, // 0x20
-    {0x00, 0x00, 0x5f, 0x00, 0x00}, // 0x21 !
-    {0x00, 0x07, 0x00, 0x07, 0x00}, // 0x22 "
-    {0x14, 0x7f, 0x14, 0x7f, 0x14}, // 0x23 #
-    {0x24, 0x2a, 0x7f, 0x2a, 0x12}, // 0x24 $
-    {0x23, 0x13, 0x08, 0x64, 0x62}, // 0x25 %
-    {0x36, 0x49, 0x55, 0x22, 0x50}, // 0x26 &
-    {0x00, 0x05, 0x03, 0x00, 0x00}, // 0x27 '
-    {0x00, 0x1c, 0x22, 0x41, 0x00}, // 0x28 (
-    {0x00, 0x41, 0x22, 0x1c, 0x00}, // 0x29 )
-    {0x14, 0x08, 0x3e, 0x08, 0x14}, // 0x2a *
-    {0x08, 0x08, 0x3e, 0x08, 0x08}, // 0x2b +
-    {0x00, 0x50, 0x30, 0x00, 0x00}, // 0x2c ,
-    {0x08, 0x08, 0x08, 0x08, 0x08}, // 0x2d -
-    {0x00, 0x60, 0x60, 0x00, 0x00}, // 0x2e .
-    {0x20, 0x10, 0x08, 0x04, 0x02}, // 0x2f /
-    {0x3e, 0x51, 0x49, 0x45, 0x3e}, // 0x30 0
-    {0x00, 0x42, 0x7f, 0x40, 0x00}, // 0x31 1
-    {0x42, 0x61, 0x51, 0x49, 0x46}, // 0x32 2
-    {0x21, 0x41, 0x45, 0x4b, 0x31}, // 0x33 3
-    {0x18, 0x14, 0x12, 0x7f, 0x10}, // 0x34 4
-    {0x27, 0x45, 0x45, 0x45, 0x39}, // 0x35 5
-    {0x3c, 0x4a, 0x49, 0x49, 0x30}, // 0x36 6
-    {0x01, 0x71, 0x09, 0x05, 0x03}, // 0x37 7
-    {0x36, 0x49, 0x49, 0x49, 0x36}, // 0x38 8
-    {0x06, 0x49, 0x49, 0x29, 0x1e}, // 0x39 9
-    {0x00, 0x36, 0x36, 0x00, 0x00}, // 0x3a :
-    {0x00, 0x56, 0x36, 0x00, 0x00}, // 0x3b ;
-    {0x08, 0x14, 0x22, 0x41, 0x00}, // 0x3c <
-    {0x14, 0x14, 0x14, 0x14, 0x14}, // 0x3d =
-    {0x00, 0x41, 0x22, 0x14, 0x08}, // 0x3e >
-    {0x02, 0x01, 0x51, 0x09, 0x06}, // 0x3f ?
-    {0x32, 0x49, 0x79, 0x41, 0x3e}, // 0x40 @
-    {0x7e, 0x11, 0x11, 0x11, 0x7e}, // 0x41 A
-    {0x7f, 0x49, 0x49, 0x49, 0x36}, // 0x42 B
-    {0x3e, 0x41, 0x41, 0x41, 0x22}, // 0x43 C
-    {0x7f, 0x41, 0x41, 0x22, 0x1c}, // 0x44 D
-    {0x7f, 0x49, 0x49, 0x49, 0x41}, // 0x45 E
-    {0x7f, 0x09, 0x09, 0x09, 0x01}, // 0x46 F
-    {0x3e, 0x41, 0x49, 0x49, 0x7a}, // 0x47 G
-    {0x7f, 0x08, 0x08, 0x08, 0x7f}, // 0x48 H
-    {0x00, 0x41, 0x7f, 0x41, 0x00}, // 0x49 I
-    {0x20, 0x40, 0x41, 0x3f, 0x01}, // 0x4a J
-    {0x7f, 0x08, 0x14, 0x22, 0x41}, // 0x4b K
-    {0x7f, 0x40, 0x40, 0x40, 0x40}, // 0x4c L
-    {0x7f, 0x02, 0x0c, 0x02, 0x7f}, // 0x4d M
-    {0x7f, 0x04, 0x08, 0x10, 0x7f}, // 0x4e N
-    {0x3e, 0x41, 0x41, 0x41, 0x3e}, // 0x4f O
-    {0x7f, 0x09, 0x09, 0x09, 0x06}, // 0x50 P
-    {0x3e, 0x41, 0x51, 0x21, 0x5e}, // 0x51 Q
-    {0x7f, 0x09, 0x19, 0x29, 0x46}, // 0x52 R
-    {0x46, 0x49, 0x49, 0x49, 0x31}, // 0x53 S
-    {0x01, 0x01, 0x7f, 0x01, 0x01}, // 0x54 T
-    {0x3f, 0x40, 0x40, 0x40, 0x3f}, // 0x55 U
-    {0x1f, 0x20, 0x40, 0x20, 0x1f}, // 0x56 V
-    {0x3f, 0x40, 0x38, 0x40, 0x3f}, // 0x57 W
-    {0x63, 0x14, 0x08, 0x14, 0x63}, // 0x58 X
-    {0x07, 0x08, 0x70, 0x08, 0x07}, // 0x59 Y
-    {0x61, 0x51, 0x49, 0x45, 0x43}, // 0x5a Z
-    {0x00, 0x7f, 0x41, 0x41, 0x00}, // 0x5b [
-    {0x02, 0x04, 0x08, 0x10, 0x20}, // 0x5c \ (keep this to escape the backslash)
-    {0x00, 0x41, 0x41, 0x7f, 0x00}, // 0x5d ]
-    {0x04, 0x02, 0x01, 0x02, 0x04}, // 0x5e ^
-    {0x40, 0x40, 0x40, 0x40, 0x40}, // 0x5f _
-    {0x00, 0x01, 0x02, 0x04, 0x00}, // 0x60 `
-    {0x20, 0x54, 0x54, 0x54, 0x78}, // 0x61 a
-    {0x7f, 0x48, 0x44, 0x44, 0x38}, // 0x62 b
-    {0x38, 0x44, 0x44, 0x44, 0x20}, // 0x63 c
-    {0x38, 0x44, 0x44, 0x48, 0x7f}, // 0x64 d
-    {0x38, 0x54, 0x54, 0x54, 0x18}, // 0x65 e
-    {0x08, 0x7e, 0x09, 0x01, 0x02}, // 0x66 f
-    {0x0c, 0x52, 0x52, 0x52, 0x3e}, // 0x67 g
-    {0x7f, 0x08, 0x04, 0x04, 0x78}, // 0x68 h
-    {0x00, 0x44, 0x7d, 0x40, 0x00}, // 0x69 i
-    {0x20, 0x40, 0x44, 0x3d, 0x00}, // 0x6a j
-    {0x7f, 0x10, 0x28, 0x44, 0x00}, // 0x6b k
-    {0x00, 0x41, 0x7f, 0x40, 0x00}, // 0x6c l
-    {0x7c, 0x04, 0x18, 0x04, 0x78}, // 0x6d m
-    {0x7c, 0x08, 0x04, 0x04, 0x78}, // 0x6e n
-    {0x38, 0x44, 0x44, 0x44, 0x38}, // 0x6f o
-    {0x7c, 0x14, 0x14, 0x14, 0x08}, // 0x70 p
-    {0x08, 0x14, 0x14, 0x18, 0x7c}, // 0x71 q
-    {0x7c, 0x08, 0x04, 0x04, 0x08}, // 0x72 r
-    {0x48, 0x54, 0x54, 0x54, 0x20}, // 0x73 s
-    {0x04, 0x3f, 0x44, 0x40, 0x20}, // 0x74 t
-    {0x3c, 0x40, 0x40, 0x20, 0x7c}, // 0x75 u
-    {0x1c, 0x20, 0x40, 0x20, 0x1c}, // 0x76 v
-    {0x3c, 0x40, 0x30, 0x40, 0x3c}, // 0x77 w
-    {0x44, 0x28, 0x10, 0x28, 0x44}, // 0x78 x
-    {0x0c, 0x50, 0x50, 0x50, 0x3c}, // 0x79 y
-    {0x44, 0x64, 0x54, 0x4c, 0x44}, // 0x7a z
-    {0x00, 0x08, 0x36, 0x41, 0x00}, // 0x7b {
-    {0x00, 0x00, 0x7f, 0x00, 0x00}, // 0x7c |
-    {0x00, 0x41, 0x36, 0x08, 0x00}, // 0x7d }
-    {0x10, 0x08, 0x08, 0x10, 0x08}, // 0x7e ~
-    {0x78, 0x46, 0x41, 0x46, 0x78}, // 0x7f DEL
-};
-
-/* The displayMap variable stores a buffer representation of the
-pixels on our display. There are 504 total bits in this array,
-same as how many pixels there are on a 84 x 48 display.
-
-Each byte in this array covers a 8-pixel vertical block on the
-display. Each successive byte covers the next 8-pixel column over
-until you reach the right-edge of the display and step down 8 rows.
-
-To update the display, we first have to write to this array, then
-call the updateDisplay() function, which sends this whole array
-to the PCD8544.
-
-Because the PCD8544 won't let us write individual pixels at a
-time, this is how we can make targeted changes to the display. */
-static uint8_t displayMap[LCD_WIDTH * LCD_HEIGHT / 8];
-
-// There are two memory banks in the LCD, data/RAM and commands.
-// This function sets the DC pin high or low depending, and then
-// sends the data byte
-static void LCD_SendBytes(bool data_or_command, const uint8_t *data, size_t len)
-{
-    esp_err_t ret;
-    spi_transaction_t t;
-    if (len == 0) return;             //no need to send anything
-    memset(&t, 0, sizeof(t));       //Zero out the transaction
-    t.length = len * 8;                 //Len is in bytes, transaction length is in bits.
-    t.tx_buffer = data;               //Data
-    t.user = (void *) data_or_command;                //D/C
-    ret = spi_device_polling_transmit(hSPI, &t);  //Transmit!
-    assert(ret == ESP_OK);            //Should have had no issues.
-}
-
-// There are two memory banks in the LCD, data/RAM and commands.
-// This function sets the DC pin high or low depending, and then
-// sends the data byte
-static void LCD_SendByte(bool data_or_command, uint8_t data)
-{
-    esp_err_t ret;
-    spi_transaction_t t;
-    memset(&t, 0, sizeof(t));       //Zero out the transaction
-    t.length = 8;                 // transaction length is in bits.
-    t.tx_data[0] = data;               //Data
-    t.flags = SPI_TRANS_USE_TXDATA;
-    t.user = (void *) data_or_command;                //D/C
-    ret = spi_device_polling_transmit(hSPI, &t);  //Transmit!
-    assert(ret == ESP_OK);            //Should have had no issues.
-}
-
-// This function sets a pixel on displayMap to your preferred
-// color. 1=Black, 0= white.
-void LCD_setPixel(int x, int y, bool bw)
-{
-    // First, double check that the coordinate is in range.
-    if ((x >= 0) && (x < LCD_WIDTH) && (y >= 0) && (y < LCD_HEIGHT)) {
-        uint8_t shift = y % 8;
-
-        if (bw) // If black, set the bit.
-            displayMap[x + (y / 8) * LCD_WIDTH] |= 1 << shift;
-        else   // If white clear the bit.
-            displayMap[x + (y / 8) * LCD_WIDTH] &= ~(1 << shift);
-    }
-}
-
-// setLine draws a line from x0,y0 to x1,y1 with the set color.
-// This function was grabbed from the SparkFun ColorLCDShield
-// library.
-void LCD_setLine(int x0, int y0, int x1, int y1, bool bw)
-{
-    int dy = y1 - y0; // Difference between y0 and y1
-    int dx = x1 - x0; // Difference between x0 and x1
-    int stepx, stepy;
-
-    if (dy < 0) {
-        dy = -dy;
-        stepy = -1;
-    }
-    else
-        stepy = 1;
-
-    if (dx < 0) {
-        dx = -dx;
-        stepx = -1;
-    }
-    else
-        stepx = 1;
-
-    dy <<= 1; // dy is now 2*dy
-    dx <<= 1; // dx is now 2*dx
-    LCD_setPixel(x0, y0, bw); // Draw the first pixel.
-
-    if (dx > dy) {
-        int fraction = dy - (dx >> 1);
-        while (x0 != x1) {
-            if (fraction >= 0) {
-                y0 += stepy;
-                fraction -= dx;
-            }
-            x0 += stepx;
-            fraction += dy;
-            LCD_setPixel(x0, y0, bw);
-        }
-    }
-    else {
-        int fraction = dx - (dy >> 1);
-        while (y0 != y1) {
-            if (fraction >= 0) {
-                x0 += stepx;
-                fraction -= dy;
-            }
-            y0 += stepy;
-            fraction += dx;
-            LCD_setPixel(x0, y0, bw);
-        }
-    }
-}
-
-// setRect will draw a rectangle from x0,y0 top-left corner to
-// a x1,y1 bottom-right corner. Can be filled with the fill
-// parameter, and colored with bw.
-// This function was grabbed from the SparkFun ColorLCDShield
-// library.
-void LCD_setRect(int x0, int y0, int x1, int y1, bool fill, bool bw)
-{
-    // check if the rectangle is to be filled
-    if (fill == 1) {
-        int xDiff;
-
-        if (x0 > x1)
-            xDiff = x0 - x1; //Find the difference between the x vars
-        else
-            xDiff = x1 - x0;
-
-        while (xDiff > 0) {
-            LCD_setLine(x0, y0, x0, y1, bw);
-
-            if (x0 > x1)
-                x0--;
-            else
-                x0++;
-
-            xDiff--;
-        }
-    }
-    else {
-        // best way to draw an unfilled rectangle is to draw four lines
-        LCD_setLine(x0, y0, x1, y0, bw);
-        LCD_setLine(x0, y1, x1, y1, bw);
-        LCD_setLine(x0, y0, x0, y1, bw);
-        LCD_setLine(x1, y0, x1, y1, bw);
-    }
-}
-
-// setCircle draws a circle centered around x0,y0 with a defined
-// radius. The circle can be black or white. And have a line
-// thickness ranging from 1 to the radius of the circle.
-// This function was grabbed from the SparkFun ColorLCDShield
-// library.
-void LCD_setCircle(int x0, int y0, int radius, bool bw, int lineThickness)
-{
-    for (int r = 0; r < lineThickness; r++) {
-        int f = 1 - radius;
-        int ddF_x = 0;
-        int ddF_y = -2 * radius;
-        int x = 0;
-        int y = radius;
-
-        LCD_setPixel(x0, y0 + radius, bw);
-        LCD_setPixel(x0, y0 - radius, bw);
-        LCD_setPixel(x0 + radius, y0, bw);
-        LCD_setPixel(x0 - radius, y0, bw);
-
-        while (x < y) {
-            if (f >= 0) {
-                y--;
-                ddF_y += 2;
-                f += ddF_y;
-            }
-            x++;
-            ddF_x += 2;
-            f += ddF_x + 1;
-
-            LCD_setPixel(x0 + x, y0 + y, bw);
-            LCD_setPixel(x0 - x, y0 + y, bw);
-            LCD_setPixel(x0 + x, y0 - y, bw);
-            LCD_setPixel(x0 - x, y0 - y, bw);
-            LCD_setPixel(x0 + y, y0 + x, bw);
-            LCD_setPixel(x0 - y, y0 + x, bw);
-            LCD_setPixel(x0 + y, y0 - x, bw);
-            LCD_setPixel(x0 - y, y0 - x, bw);
-        }
-        radius--;
-    }
-}
-
-// This function will draw a char (defined in the ASCII table
-// near the beginning of this sketch) at a defined x and y).
-// The color can be either black (1) or white (0).
-void LCD_setChar(char character, int x, int y, bool bw)
-{
-    uint8_t column; // temp byte to store character's column bitmap
-    for (int i = 0; i < 5; i++) // 5 columns (x) per character
-    {
-        column = ASCII[character - 0x20][i];
-        for (int j = 0; j < 8; j++) // 8 rows (y) per character
-        {
-            if (column & (0x01 << j)) // test bits to set pixels
-                LCD_setPixel(x + i, y + j, bw);
-            else
-                LCD_setPixel(x + i, y + j, !bw);
-        }
-    }
-}
-
-// setStr draws a string of characters, calling setChar with
-// progressive coordinates until it's done.
-// This function was grabbed from the SparkFun ColorLCDShield
-// library.
-void LCD_setStr(const char *dString, int x, int y, bool bw)
-{
-    while (*dString != 0x00) // loop until null terminator
-    {
-        LCD_setChar(*dString++, x, y, bw);
-        x += 5;
-        for (int i = y; i < y + 8; i++) {
-            LCD_setPixel(x, i, !bw);
-        }
-        x++;
-        if (x > (LCD_WIDTH - 5)) // Enables wrap around
-        {
-            x = 0;
-            y += 8;
-        }
-    }
-}
-
-// This function will draw an array over the screen. (For now) the
-// array must be the same size as the screen, covering the entirety
-// of the display.
-// Also, the array must reside in FLASH and declared with PROGMEM.
-void LCD_setBitmap(const char *bitArray)
-{
-    for (int i = 0; i < (LCD_WIDTH * LCD_HEIGHT / 8); i++) {
-        char c = bitArray[i];
-        displayMap[i] = c;
-    }
-}
-
-// This function clears the entire display either white (0) or
-// black (1).
-// The screen won't actually clear until you call updateDisplay()!
-void LCD_clearDisplay(bool bw)
-{
-    for (int i = 0; i < (LCD_WIDTH * LCD_HEIGHT / 8); i++) {
-        if (bw)
-            displayMap[i] = 0xFF;
-        else
-            displayMap[i] = 0;
-    }
-}
-
-// Helpful function to directly command the LCD to go to a
-// specific x,y coordinate.
-static void gotoXY(int x, int y)
-{
-    const uint8_t cmd[2] = {
-        0x80 | x,
-        0x40 | y,
-    };
-    LCD_SendBytes(LCD_COMMAND, cmd, 2);
-}
-
-// This will actually draw on the display, whatever is currently
-// in the displayMap array.
-void LCD_updateDisplay()
-{
-    spi_device_acquire_bus(hSPI, portMAX_DELAY);
-    gotoXY(0, 0);
-    LCD_SendBytes(LCD_DATA, &displayMap[0], LCD_WIDTH * (LCD_HEIGHT / 8));
-    spi_device_release_bus(hSPI);
-}
-
-// Set contrast can set the LCD Vop to a value between 0 and 127.
-// 40-60 is usually a pretty good range.
-void LCD_setContrast(uint8_t contrast)
-{
-    spi_device_acquire_bus(hSPI, portMAX_DELAY);
-    const uint8_t cmd[3] = {
-        0x21,  //Tell LCD that extended commands follow
-        0x80 | contrast,//Set LCD Vop (Contrast): Try 0xB1(good @ 3.3V) or 0xBF if your display is too dark
-        0x20,//Set display mode
-    };
-    LCD_SendBytes(LCD_COMMAND, cmd, 3);
-    spi_device_release_bus(hSPI);
-}
-
-void LCD_invertDisplay(bool invert)
-{
-    LCD_SendByte(LCD_COMMAND, 0x0C | invert);
-}
-
-void LCD_invertDisplayData()
-{
-    /* Indirect, swap bits in displayMap option: */
-    for (int i = 0; i < (LCD_WIDTH * LCD_HEIGHT / 8); i++) {
-        displayMap[i] ^= 0xFF;
-    }
-}
-
-//This function is called (in irq context!) just before a transmission starts. It will
-//set the D/C line to the value indicated in the user field.
-void lcd_spi_pre_transfer_callback(spi_transaction_t *t)
-{
-    int dc = (int) t->user;
-    gpio_set_level(dcPin, dc);
-}
-
-//This sends the magical commands to the PCD8544
-void LCD_setup(void)
-{
-    // clear the display array
-    LCD_clearDisplay(0);
-
-    gpio_config_t output = {
-        .pin_bit_mask = (1<<scePin) | (1<<rstPin) | (1<<dcPin) | (1<<sdinPin) | (1<<sclkPin),
-        .mode = GPIO_MODE_OUTPUT
-    };
-    gpio_config(&output);
-
-    esp_err_t ret;
-    spi_bus_config_t buscfg = {
-        .miso_io_num=-1,
-        .mosi_io_num=sdinPin,
-        .sclk_io_num=sclkPin,
-        .quadwp_io_num=-1,
-        .quadhd_io_num=-1,
-        .max_transfer_sz=LCD_WIDTH * LCD_HEIGHT, // ??? this doesnt seem to do anything in the driver
-    };
-    spi_device_interface_config_t devcfg = {
-        .clock_speed_hz=4 * 1000 * 1000, // Hz
-        // enable signal lead/lag
-        .cs_ena_pretrans = 0,
-        .cs_ena_posttrans = 0,
-        .mode=0,                            //SPI mode 0
-        .spics_io_num=scePin,               //CS pin
-        .queue_size=1, // we use the polling mode, so this does not matter
-        .pre_cb=lcd_spi_pre_transfer_callback,  //Specify pre-transfer callback to handle D/C line
-    };
-
-    //Initialize the SPI bus
-    ret = spi_bus_initialize(HSPI_HOST, &buscfg, 1);
-    ESP_ERROR_CHECK(ret);
-    //Attach the LCD to the SPI bus
-    ret = spi_bus_add_device(HSPI_HOST, &devcfg, &hSPI);
-    ESP_ERROR_CHECK(ret);
-
-    spi_device_acquire_bus(hSPI, portMAX_DELAY);
-    {
-        //Reset the LCD to a known state
-        gpio_set_level(rstPin, 0);
-        gpio_set_level(rstPin, 1);
-
-        const uint8_t magic[6] = {
-            0x21, // Tell LCD extended commands follow
-            0x80 + DEFAULT_CONTRAST, // Set LCD Vop (Contrast)
-            0x04, // Set Temp coefficent
-            0x14, // LCD bias mode 1:48 (try 0x13)
-            //We must send 0x20 before modifying the display control mode
-            0x20, // Clear extended option
-            0x0C, // Set display control, normal mode.
-        };
-        LCD_SendBytes(LCD_COMMAND, &magic[0], 6);
-    }
-    spi_device_release_bus(hSPI);
-
-    // show the blank screen (display is in indefined state after boot)
-    LCD_updateDisplay();
-}
-
-