diff options
| -rw-r--r-- | Makefile | 44 | ||||
| -rw-r--r-- | uart.c | 33 | ||||
| -rw-r--r-- | uart.h | 8 |
3 files changed, 85 insertions, 0 deletions
diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..8762701 --- /dev/null +++ b/Makefile @@ -0,0 +1,44 @@ +CC = avr-gcc +MCU = atmega328p +TARGET = app + +SRC = main.c uart.c +OBJ = $(SRC:.c=.o) + +CFLAGS = -std=gnu99 +CFLAGS += -Os +CFLAGS += -Wall +CFLAGS += -mmcu=$(MCU) +CFLAGS += -DBAUD=115200 +CFLAGS += -DF_CPU=16000000UL +CFLAGS += -ffunction-sections -fdata-sections + +LDFLAGS = -mmcu=$(MCU) +LDFLAGS += -Wl,--gc-sections + +HEX_FLAGS = -O ihex +HEX_FLAGS += -j .text -j .data + +AVRDUDE_FLAGS = -p $(MCU) +AVRDUDE_FLAGS += -c arduino +AVRDUDE_FLAGS += -P /dev/cuaU0 +AVRDUDE_FLAGS += -D -U + +%.o: %.c + $(CC) $(CFLAGS) -c -o $@ $< + +elf: $(OBJ) + $(CC) $(LDFLAGS) $(OBJ) -o $(TARGET).elf + +hex: elf + avr-objcopy $(HEX_FLAGS) $(TARGET).elf $(TARGET).hex + +upload: hex + avrdude $(AVRDUDE_FLAGS) flash:w:$(TARGET).hex:i + +.PHONY: clean + +clean: + rm *.o *.elf *.hex + + @@ -0,0 +1,33 @@ +#include <avr/io.h> +#include <util/setbaud.h> + +#include "uart.h" + +void uart_init(void) +{ + UBRR0H = UBRRH_VALUE; + UBRR0L = UBRRL_VALUE; +#if USE_2X + UCSR0A |= (1 << U2X0); +#else + UCSR0A &= ~(1 << U2X0); +#endif + UCSR0B = (1 << TXEN0) | (1 << RXEN0); + UCSR0C = (1 << UCSZ01) | (1 << UCSZ00); +} + +void uart_write(char c) +{ + while (!(UCSR0A & (1 << UDRE0))) + ; + UDR0 = c; +} + +void uart_write_line(const char *s) +{ + for (; *s; s++) + uart_write(*s); + + uart_write('\r'); + uart_write('\n'); +} @@ -0,0 +1,8 @@ +#ifndef UART_H +#define UART_H + +void uart_init(void); +void uart_write(char c); +void uart_write_line(const char *s); + +#endif /* UART_H */ |