correct wind calc & use dht22

Makefile

@@ -3,7 +3,7 @@
 # project subdirectory.
 #
 
-DUMMY_VAR = 2
+DUMMY_VAR = 1
 PROJECT_NAME := meteo
 
 include $(IDF_PATH)/make/project.mk

components/circbuf/CMakeLists.txt

@@ -0,0 +1,5 @@
+set(COMPONENT_ADD_INCLUDEDIRS .)
+
+set(COMPONENT_SRCS "circbuf.c")
+
+register_component()

components/circbuf/circbuf.c

@@ -0,0 +1,260 @@
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+
+#include "circbuf.h"
+
+// --- Circbuf data structure ----
+
+/** Offset in void* buffer */
+#define PV_OFFS(pvBuf, elem_size, index) ((uint8_t*)(pvBuf) + ((elem_size)*(index)))
+
+
+/**
+ * @brief Write data to a CircBuf slot
+ * @param cb     : circbuf
+ * @param index  : slot index
+ * @param source : data source
+ */
+static inline void write_buffer(CircBuf *cb, circbuf_size_t index, const void *source)
+{
+    memcpy(PV_OFFS(cb->buf, cb->elem_size, index), source, cb->elem_size);
+}
+
+
+/**
+ * @brief Copy data from a CircBuf slot to a buffer
+ * @param cb     : circbuf
+ * @param index  : slot index
+ * @param dest   : destination buffer
+ */
+static inline void read_buffer(const CircBuf *cb, circbuf_size_t index, void *dest)
+{
+    memcpy(dest, PV_OFFS(cb->buf, cb->elem_size, index), cb->elem_size);
+}
+
+/** Get index of the front position (for write) */
+static inline circbuf_size_t front_writepos(const CircBuf *cb) {
+    return (cb->back + cb->num_used) % cb->cap;
+}
+
+
+void cbuf_init(CircBuf *cb, void *buf, circbuf_size_t capacity, circbuf_size_t elem_size)
+{
+    // allocate the buffer
+    cb->buf = buf;
+
+    // set capacity, clear state
+    cb->elem_size = elem_size;
+    cb->cap = capacity;
+
+    cbuf_clear(cb);
+}
+
+
+/** Check if cbuf is full */
+bool cbuf_full(const CircBuf *cb)
+{
+    if (cb == NULL) {
+        return false;
+    }
+
+    return cb->num_used == cb->cap;
+}
+
+
+/** Check if cbuf is empty */
+bool cbuf_empty(const CircBuf *cb)
+{
+    if (cb == NULL) {
+        return true;
+    }
+
+    return cb->num_used == 0;
+}
+
+
+/** Get the max capacity of the buffer */
+circbuf_size_t cbuf_capacity(const CircBuf *cb)
+{
+    return cb->cap;
+}
+
+
+/** Get the current number of items in the buffer */
+circbuf_size_t cbuf_count(const CircBuf *cb)
+{
+    return cb->num_used;
+}
+
+
+/** Push one element to the front_writepos */
+bool cbuf_push(CircBuf *cb, const void *source)
+{
+    if (cb == NULL || source == NULL || cb->num_used == cb->cap) {
+        return false;
+    }
+
+    write_buffer(cb, front_writepos(cb), source);
+
+    // increment
+    cb->num_used++;
+
+    return true;
+}
+
+
+/** Pop one element from the front_writepos */
+bool cbuf_pop(CircBuf *cb, void *dest)
+{
+    if (cb == NULL || cb->num_used == 0) {
+        return false;
+    }
+
+    cb->num_used--;
+
+    circbuf_size_t f = front_writepos(cb);
+
+    if (dest != NULL) {
+        read_buffer(cb, f, dest);
+    }
+
+#ifdef CIRCBUF_ZERO_FREE_SLOTS
+    memset(PV_OFFS(cb->buf, cb->elem_size, f), 0, cb->elem_size);
+#endif
+
+    return true;
+}
+
+
+/** Peek at the front_writepos element */
+bool cbuf_peek(const CircBuf *cb, void *dest)
+{
+    if (cb == NULL || dest == NULL || cb->num_used == 0) {
+        return false;
+    }
+
+    circbuf_size_t f = (cb->back + cb->num_used - 1) % cb->cap;
+    read_buffer(cb, f, dest);
+    return true;
+}
+
+
+void * cbuf_ptr(const CircBuf *cb)
+{
+    if (cb == NULL || cb->num_used == 0) {
+        return NULL;
+    }
+
+    circbuf_size_t f = (cb->back + cb->num_used - 1) % cb->cap;
+    return PV_OFFS(cb->buf, cb->elem_size, f);
+}
+
+
+/** Peek at the nth element (counted from back) */
+bool cbuf_nth(const CircBuf *cb, circbuf_size_t num, void *dest)
+{
+    if (cb == NULL || dest == NULL || num > cb->num_used) {
+        return false;
+    }
+
+    circbuf_size_t index = (cb->back + num) % cb->cap;
+    read_buffer(cb, index, dest);
+    return true;
+}
+
+
+void *cbuf_ptr_nth(const CircBuf *cb, circbuf_size_t num)
+{
+    if (cb == NULL || num > cb->num_used) {
+        return NULL;
+    }
+
+    circbuf_size_t index = (cb->back + num) % cb->cap;
+    return PV_OFFS(cb->buf, cb->elem_size, index);
+}
+
+
+/** Push one element to the back */
+bool cbuf_push_back(CircBuf *cb, const void *source)
+{
+    if (cb == NULL || source == NULL || cb->num_used == cb->cap) {
+        return false;
+    }
+
+    // move lr back
+    if (cb->back == 0) {
+        cb->back = cb->cap - 1; // wrap to the end
+    } else {
+        cb->back--;
+    }
+    cb->num_used++;
+
+    write_buffer(cb, cb->back, source);
+
+    return true;
+}
+
+
+/** Pop one element from the back */
+bool cbuf_pop_back(CircBuf *cb, void *dest)
+{
+    if (cb == NULL || cb->num_used == 0) {
+        return false;
+    }
+
+    if (dest != NULL) {
+        read_buffer(cb, cb->back, dest);
+    }
+
+#ifdef CIRCBUF_ZERO_FREE_SLOTS
+    memset(PV_OFFS(cb->buf, cb->elem_size, cb->back), 0, cb->elem_size);
+#endif
+
+    // increment
+    cb->back++;
+    if (cb->back == cb->cap) {
+        cb->back = 0;
+    }
+    cb->num_used--;
+
+    return true;
+}
+
+
+/** Pop one element from the back */
+bool cbuf_peek_back(const CircBuf *cb, void *dest)
+{
+    if (cb == NULL || dest == NULL || cb->num_used == 0) {
+        return false;
+    }
+
+    read_buffer(cb, cb->back, dest);
+    return true;
+}
+
+
+void* cbuf_ptr_back(const CircBuf *cb)
+{
+    if (cb == NULL || cb->num_used == 0) {
+        return NULL;
+    }
+
+    return PV_OFFS(cb->buf, cb->elem_size, cb->back);
+}
+
+
+/** Clear a cbuf */
+void cbuf_clear(CircBuf *cb)
+{
+    if (cb == NULL) {
+        return;
+    }
+
+    cb->num_used = 0;
+    cb->back = 0;
+
+#ifdef CIRCBUF_ZERO_FREE_SLOTS
+    memset(PV_OFFS(cb->buf, cb->elem_size, 0), 0, cb->cap * cb->elem_size);
+#endif
+}

components/circbuf/circbuf.h

@@ -0,0 +1,151 @@
+/**
+ * @file circbuf.h
+ * @author Ondřej Hruška, 2016,2023
+ *
+ * Circular buffer / queue / stack.
+ * Slots are pre-allocated, values are copied into the buffer.
+ *
+ * The buffer may be used as a stack, event queue or a simple buffer.
+ *
+ * MIT license
+ */
+
+#ifndef CIRCBUF_H
+#define CIRCBUF_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stdlib.h>
+
+// Enable to zero a freed slots after pop, useful for debugging
+#define CIRCBUF_ZERO_FREE_SLOTS
+
+// size_t can be replaced by a more suitable type for circbuf, e.g. uint8_t for tiny buffers
+typedef uint32_t circbuf_size_t;
+
+/** Instance structure - public to allow static allocation, but consider the structure internal matter */
+struct circbuf_struct {
+  void *buf;
+  circbuf_size_t num_used;
+  circbuf_size_t elem_size;
+  circbuf_size_t cap;
+  circbuf_size_t back;
+//  circbuf_size_t front;
+};
+
+typedef struct circbuf_struct CircBuf;
+
+/**
+ * @brief Initialize a circular buffer
+ *
+ * @param[in,out] cb - pointer to the buffer to init, can be statically or dynamically allocated
+ * @param buf  : backing buffer, can be statically or dynamically allocated
+ * @param capacity  : buffer capacity
+ * @param elem_size : size of one element
+ */
+void cbuf_init(CircBuf *cb, void *buf, circbuf_size_t capacity, circbuf_size_t elem_size);
+
+
+/** Test for full buffer */
+bool cbuf_full(const CircBuf *cb);
+
+
+/** Test for empty buffer */
+bool cbuf_empty(const CircBuf *cb);
+
+
+/** Get the max capacity of the buffer */
+circbuf_size_t cbuf_capacity(const CircBuf *cb);
+
+
+/** Get the current number of items in the buffer */
+circbuf_size_t cbuf_count(const CircBuf *cb);
+
+
+/** Peek at the nth element (counted from back) */
+bool cbuf_nth(const CircBuf *cb, circbuf_size_t num, void *dest);
+
+
+/** Get a mutable reference to nth element (counted from back) */
+void *cbuf_ptr_nth(const CircBuf *cb, circbuf_size_t num);
+
+
+/** @brief Remove all data from buffer */
+void cbuf_clear(CircBuf *cb);
+
+
+/**
+ * @brief Append a value to the buffer (FIFO)
+ * @param cb     : buffer
+ * @param source : pointer to a value (will be copied)
+ * @return success
+ */
+bool cbuf_push(CircBuf *cb, const void *source);
+
+
+/**
+ * @brief Read a value from the buffer, return susccess.
+ *
+ * @param cb   : buffer
+ * @param dest : read destination. If NULL, value is discarded.
+ * @return success
+ */
+bool cbuf_pop(CircBuf *cb, void *dest);
+
+
+/**
+ * @brief Copy the frontmost element without changing the buffer
+ * @param cb   : buffer
+ * @param dest : read destination
+ * @return success
+ */
+bool cbuf_peek(const CircBuf *cb, void *dest);
+
+
+/**
+ * @brief Get a mutable reference to the front element
+ * @param cb   : buffer
+ * @param dest : read destination
+ * @return reference or NULL
+ */
+void * cbuf_ptr(const CircBuf *cb);
+
+
+/**
+ * @brief Push a value into the circbuf (LIFO).
+ *
+ * @param cb     : buffer
+ * @param source : pointer to a value (will be copied)
+ * @return success
+ */
+bool cbuf_push_back(CircBuf *cb, const void *source);
+
+
+/**
+ * @brief Read a value from the buffer, return susccess.
+ *
+ * @param cb   : buffer
+ * @param dest : read destination. If NULL, value is discarded.
+ * @return success
+ */
+bool cbuf_pop_back(CircBuf *cb, void *dest);
+
+
+/**
+ * @brief Copy the backmost element without changing the buffer
+ * @param cb   : buffer
+ * @param dest : read destination
+ * @return success
+ */
+bool cbuf_peek_back(const CircBuf *cb, void *dest);
+
+
+/**
+ * @brief Get a mutable reference to the backmost element
+ * @param cb   : buffer
+ * @param dest : read destination
+ * @return reference or NULL
+ */
+void* cbuf_ptr_back(const CircBuf *cb);
+
+#endif // CIRCBUF_H

components/circbuf/component.mk

@@ -0,0 +1,10 @@
+#
+# Component Makefile
+#
+# This Makefile should, at the very least, just include $(SDK_PATH)/Makefile. By default,
+# this will take the sources in the src/ directory, compile them and link them into
+# lib(subdirectory_name).a in the build directory. This behaviour is entirely configurable,
+# please read the SDK documents if you need to do this.
+#
+
+COMPONENT_ADD_INCLUDEDIRS := .

main/meteo_task.c

@@ -11,77 +11,80 @@
 #include "ds18b20.h"
 #include "dht.h"
 #include "driver/gpio.h"
+#include "circbuf.h"
 
-static volatile uint32_t timestamp_ms = 0;
-static volatile uint32_t last_revolution_ts = 0;
+static volatile uint32_t timestamp = 0;
 
-#define RPM_BUFFER_LEN 10
-static volatile uint16_t rpm_buffer[RPM_BUFFER_LEN] = {};
-static volatile int rpm_buffer_next = 0;
-static volatile int num_valid_average = 0;
+#define RPS_BUFFER_LEN (60*10)
+static volatile uint16_t history[RPS_BUFFER_LEN] = {};
+static CircBuf rps_cb;
+
+static volatile float rpm_average = 0;
+static volatile float rpm_gust = 0;
+
+static volatile uint16_t cycle_count = 0;
+
+void calculate_wind();
 
 static void gpio_isr_handler(void *arg)
 {
-    uint32_t ts = timestamp_ms;
-    uint32_t cycle_ms = ts - last_revolution_ts;
-    last_revolution_ts = ts;
-
-    if (cycle_ms > 0xFFFF) {
-        cycle_ms = 0xFFFF;
-    }
-    rpm_buffer[rpm_buffer_next++] = (uint16_t) cycle_ms;
-    if (rpm_buffer_next == RPM_BUFFER_LEN) {
-        rpm_buffer_next = 0;
-    }
-    if (num_valid_average < RPM_BUFFER_LEN) {
-        num_valid_average++;
+    if (cycle_count < 0xFFFF) {
+        cycle_count++;
     }
 }
 
-float get_rpm() {
-    float res;
-    float current = (float)(timestamp_ms - last_revolution_ts);
-
-    if (num_valid_average > 0) {
-        // we write num_valid_average only from here, so its safe to assume it stays nonzero
-        float average = 0;
-        int pos = rpm_buffer_next;
-        for (int i = 0; i < num_valid_average; i++) {
-            average += (float) rpm_buffer[pos];
-            pos--;
-            if (pos < 0) {
-                pos = RPM_BUFFER_LEN - 1;
-            }
-        }
-        average /= (float) (num_valid_average);
-
-        // now we have ms per revolution
-
-        if (current > average * 10.0f) {
-            // if wind stopped, invalidate the averaging buffer and use the current time from the last hall event
-            res = current;
-            num_valid_average = 0; // invalidate average results
-        } else {
-            res = average;
-        }
-    } else {
-        res = current;
-    }
-
-    float rpm = 60000.0f / res;
-    if (rpm < 1) {
-        rpm = 0;
-    }
-    return rpm; // RPM
-}
-
-void hw_timer_callback1(void *arg)
+void hw_timer_callback1s(void *arg)
 {
-    timestamp_ms++;
+    timestamp++;
+
+    // FIXME use a freertos queue and pass this to a thread!
+    if (cbuf_full(&rps_cb)) {
+        cbuf_pop_back(&rps_cb, NULL);
+    }
+    cbuf_push(&rps_cb, (void*) &cycle_count);
+    cycle_count = 0;
+
+    calculate_wind();
 }
 
+void calculate_wind()
+{
+    // Wind speed is average from 10 minutes
+    // Gust is max 3-second average anywhere within the 10 minutes
+
+    float max_gust = 0;
+
+    uint32_t tenmin_sum = 0;
+    uint32_t numsecs = cbuf_count(&rps_cb);
+    uint16_t threesec1 = 0, threesec2 = 0;
+    for(size_t i = 0; i < numsecs; i++) {
+        uint16_t *slot = cbuf_ptr_nth(&rps_cb, i);
+        if (!slot) {
+            continue;
+        }
+
+        uint16_t slotval = *slot;
+        tenmin_sum += (uint32_t) slotval;
+
+        // gust is max avg from 3 seconds within the 10 minutes
+        uint32_t gust_sum = (uint32_t) threesec1 + (uint32_t) threesec2 + (uint32_t) slotval;
+        threesec1 = threesec2;
+        threesec2 = slotval;
+
+        float gust_avg = (float)gust_sum * (float)20.0f;
+        if (gust_avg > max_gust) {
+            max_gust = gust_avg;
+        }
+    }
+    rpm_gust = max_gust;
+    rpm_average = ((float)tenmin_sum / (float)numsecs) * 60.0f;
+}
+
+
 void meteo_task(void* pvParameters)
 {
+    cbuf_init(&rps_cb, (void*)history, RPS_BUFFER_LEN, 2); // uint16 fields
+
     // Try to unfuck GPIOs
     PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTDI_U, FUNC_GPIO12);
     PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTCK_U, FUNC_GPIO13);
@@ -89,8 +92,8 @@ void meteo_task(void* pvParameters)
     PIN_FUNC_SELECT(PERIPHS_IO_MUX_MTDO_U, FUNC_GPIO15);
 
     // start timer used for timebase
-    hw_timer_init(hw_timer_callback1, NULL);
-    hw_timer_alarm_us(1000, true); // 1 ms timer
+    hw_timer_init(hw_timer_callback1s, NULL);
+    hw_timer_alarm_us(1000000, true); // 1s timer
 
     gpio_config_t io_conf;
     io_conf.intr_type = GPIO_INTR_POSEDGE;
@@ -107,11 +110,12 @@ void meteo_task(void* pvParameters)
         // this works ...
         ds_temp = ds18b20_measure_and_read(0, DS18B20_ANY);
 
-        if (!dht_read_float_data(DHT_TYPE_DHT11, 12, &dht_hum, &dht_temp)) {
+        if (!dht_read_float_data(DHT_TYPE_DHT22, 12, &dht_hum, &dht_temp)) {
             dht_hum = dht_temp = NAN;
         }
 
-        printf("Dallas: %.2f °C, DHT %.2f °C, %.1f %%r.H, HALL %.1f RPM\n", ds_temp, dht_temp, dht_hum, get_rpm());
+        printf("Dallas: %.2f °C, DHT %.2f °C, %.1f %%r.H, HALL avg %.1f RPM, gust %.1f RPM\n",
+               ds_temp, dht_temp, dht_hum, rpm_average, rpm_gust);
 
         vTaskDelay(pdMS_TO_TICKS(500));
     }