added examples folder

examples/Makefile

@@ -0,0 +1,137 @@
+## === CPU settings ===
+# CPU type
+MCU	= atmega328p
+# CPU frequency
+F_CPU = 16000000
+# Fuses
+LFUSE = 0xFF
+HFUSE = 0xDE
+EFUSE = 0x05
+
+
+## === Source files ===
+# Main C file
+MAIN = uart_isr.c
+# Extra C files in this folder
+LOCAL_SOURCE =
+
+# Library directory (with C files)
+EXTRA_SOURCE_DIR = lib/
+# C files in the library directory
+EXTRA_SOURCE_FILES = uart.c
+
+
+## === Programmer ===
+PROGRAMMER_TYPE = arduino
+PROGRAMMER_ARGS = -b 57600 -P /dev/ttyUSB0
+
+
+## === C flags ===
+
+CFLAGS = -std=gnu99 -mmcu=$(MCU) -DF_CPU=$(F_CPU)UL -I. -I$(EXTRA_SOURCE_DIR)
+CFLAGS += -funsigned-char -funsigned-bitfields -fpack-struct -fshort-enums
+CFLAGS += -Wall -Wno-main -Wno-strict-prototypes -Wno-comment
+CFLAGS += -g2 -Wextra -Wfatal-errors -Wno-unused-but-set-variable
+CFLAGS += -ffunction-sections -fdata-sections -Wl,--gc-sections -Wl,--relax
+# CFLAGS += -lm  ## Math
+# CFLAGS += -Wl,-u,vfprintf -lprintf_flt -lm  ## for floating-point printf
+# CFLAGS += -Wl,-u,vfprintf -lprintf_min      ## for smaller printf
+CFLAGS_BUILD = $(CFLAGS) -Os
+
+
+# ---------------------------------------------------------------------------
+
+## Defined programs / locations
+CC = avr-gcc
+OBJCOPY = avr-objcopy
+OBJDUMP = avr-objdump
+AVRSIZE = avr-size
+AVRDUDE = avrdude
+
+## === File lists ===
+TARGET = $(strip $(basename $(MAIN)))
+SRC1 = $(TARGET).c
+SRC = $(SRC1)
+EXTRA_SOURCE = $(addprefix $(EXTRA_SOURCE_DIR), $(EXTRA_SOURCE_FILES))
+SRC += $(EXTRA_SOURCE)
+SRC += $(LOCAL_SOURCE)
+
+HEADERS = $(SRC:.c=.h)
+OBJ = $(SRC:.c=.o)
+
+
+## === File generation ===
+all: $(TARGET).hex size
+pre: $(TARGET).pre
+
+%.hex: %.elf
+	$(OBJCOPY) -R .eeprom -O ihex $< $@
+
+%.elf: $(SRC)
+	$(CC) $(CFLAGS_BUILD) $(SRC) --output $@
+
+%.pre: $(SRC1)
+	$(CC) $(CFLAGS) -E $(SRC1) --output $@
+
+%.eeprom: %.elf
+	$(OBJCOPY) -j .eeprom --change-section-lma .eeprom=0 -O ihex $< $@
+
+%.lst: %.elf
+	$(OBJDUMP) -S $< > $@
+
+# Show debug info
+debug:
+	@echo
+	@echo "Source files:"   $(SRC)
+	@echo "MCU, F_CPU, BAUD:"  $(MCU), $(F_CPU), $(BAUD)
+	@echo
+
+
+# Disassemble the ELF
+disassemble: $(TARGET).lst
+dis: disassemble
+lst: disassemble
+
+# Make eeprom file
+eeprom: $(TARGET).eeprom
+
+# Show how big the resulting program is
+size:  $(TARGET).elf
+	$(AVRSIZE) -C --mcu=$(MCU) $(TARGET).elf
+
+# Clean all produced trash
+clean:
+	rm -f $(TARGET).elf $(TARGET).hex $(TARGET).obj \
+	$(TARGET).o $(TARGET).d $(TARGET).eep $(TARGET).lst \
+	$(TARGET).lss $(TARGET).sym $(TARGET).map $(TARGET)~ \
+	$(TARGET).eeprom
+
+# Clean all trash
+purge:
+	rm -f *.elf *.hex *.obj *.o *.d *.eep *.lst *.lss *.sym *.map *~
+
+
+## === avrdude ===
+
+flash: $(TARGET).hex
+	$(AVRDUDE) -c $(PROGRAMMER_TYPE) -p $(MCU) $(PROGRAMMER_ARGS) -U flash:w:$<
+
+flashe: $(TARGET).eeprom
+	$(AVRDUDE) -c $(PROGRAMMER_TYPE) -p $(MCU) $(PROGRAMMER_ARGS) -U eeprom:w:$<
+
+shell:
+	$(AVRDUDE) -c $(PROGRAMMER_TYPE) -p $(MCU) $(PROGRAMMER_ARGS) -nt
+
+
+# === fuses ===
+
+FUSE_STRING = -U lfuse:w:$(LFUSE):m -U hfuse:w:$(HFUSE):m -U efuse:w:$(EFUSE):m
+
+fuses:
+	$(AVRDUDE) -c $(PROGRAMMER_TYPE) -p $(MCU) \
+	           $(PROGRAMMER_ARGS) $(FUSE_STRING)
+show_fuses:
+	$(AVRDUDE) -c $(PROGRAMMER_TYPE) -p $(MCU) $(PROGRAMMER_ARGS) -nv
+
+set_default_fuses:  FUSE_STRING = -U lfuse:w:$(LFUSE):m -U hfuse:w:$(HFUSE):m -U efuse:w:$(EFUSE):m
+set_default_fuses:  fuses

examples/README.md

@@ -0,0 +1,8 @@
+Library usage examples
+======================
+
+Those examples should work, but they are mostly just a reference on how to
+use different parts of the library.
+
+To try to build and flash an example, first change the `MAIN` field in the Makefile
+to it's name.

examples/lib

@@ -0,0 +1 @@
+/home/ondra/elektro/avr-lib/lib

examples/uart_isr.c

@@ -0,0 +1,38 @@
+#include <avr/io.h>
+#include <util/delay.h>
+#include <avr/pgmspace.h>
+#include <avr/interrupt.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "lib/uart.h"
+
+
+// UART receive interrupt vector
+ISR(USART_RX_vect)
+{
+	uint8_t c = uart_rx();
+
+	// print character and it's code
+	uart_putc(c);
+	uart_putc(' ');
+	uart_putu(c);
+	uart_nl();
+}
+
+
+void main()
+{
+	// Set up UART at speed 9600 baud
+	uart_init(9600);
+	// Enable receive ISR
+	uart_isr_rx(1);
+	// Enable interrupts
+	sei();
+
+	// Greeter string
+	uart_puts_pgm(PSTR("UART receiver with ISR\r\n"));
+
+	while(1);
+}

examples/uart_simple.c

@@ -0,0 +1,58 @@
+#include <avr/io.h>
+#include <util/delay.h>
+#include <avr/pgmspace.h>
+#include <avr/interrupt.h>
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "lib/uart.h"
+
+void main()
+{
+	// Enable UART with baud rate 9600
+	uart_init(9600);
+
+
+
+	// --- some examples of printing functions ---
+
+
+	// Printing a string
+	uart_puts("Simple UART example!\r\n");
+
+	// You can put your string literals in the program memory
+	// and use the _pgm variant:
+	uart_puts_pgm(PSTR("Program memory string example\r\n"));
+
+	// print a char. This is an alias for uart_tx
+	uart_putc('a');
+
+	// print a newline
+	uart_nl();
+
+	// Printing numbers is also easy
+	// Look in the library file for more info
+	uart_putn(123);
+	uart_nl();
+
+	// Print int as float (adds decimal point)
+	uart_puti(31415, 4);
+	uart_nl();
+
+
+
+	// --- receive example ---
+
+	// Example of listening for input
+	while(1) {
+		// If something is received
+		if (uart_rx_ready()) {
+			// Get the received byte
+			char c = uart_rx();
+			// Send it back, twice
+			uart_tx(c);
+			uart_tx(c);
+		}
+	}
+}

lib/uart.h

@@ -65,10 +65,10 @@ void uart_puts_pgm(const char* str);
 // Numbers
 
 /** Send unsigned int */
-void uart_putn(const int8_t num);
+void uart_putu(const uint8_t num);
 
 /** Send signed int */
-void uart_putu(const uint8_t num);
+void uart_putn(const int8_t num);
 
 /** Send unsigned int */
 void uart_puti(const int16_t num, const uint8_t places);
@@ -76,12 +76,12 @@ void uart_puti(const int16_t num, const uint8_t places);
 /** Send signed int */
 void uart_putiu(const uint16_t num, const uint8_t places);
 
-/** Send unsigned long */
-void uart_putlu(const uint32_t num, const uint8_t places);
-
 /** Send signed long */
 void uart_putl(const int32_t num, const uint8_t places);
 
+/** Send unsigned long */
+void uart_putlu(const uint32_t num, const uint8_t places);
+
 // Extras
 
 /** Send CRLF */