# Arduino Nano with ATmega328P programming script
# detailed configuration on http://arduino.cc/en/uploads/Main/boards.txt
# required packages: avrdude gcc-avr avr-libc

# the output firmware name
TARGET=scale
# to compile
CC=avr-gcc
OBJDUMP=avr-objdump
OBJCOPY=avr-objcopy
SIZE=avr-size
CFLAGS=-g -Wall -Werror -O3 -std=c99
# for this project we need float capable printf
LDFLAGS=-lm -Wl,-u,vfprintf -lprintf_flt
# the target (arduino nano)
DEVICE=atmega328p
F_CPU=16000000UL
# the flasher
PROGRAMMER=arduino
PORT=/dev/ttyUSB0
# to flash
# use the aduino bootlaoder, with a baudrate of 57600
# reset the device to start bootlaoder
FLASHER=avrdude -p $(DEVICE) -c $(PROGRAMMER) -P $(PORT) -b 57600 -D
# source files to compile
SRC = $(wildcard *.c)
# header files.
HEADER = $(SRC:.c=.h)
# object files.
OBJ = $(SRC:.c=.o)
# listing files.
LST = $(SRC:.c=.lst)

all: compile $(TARGET).lst flash
	echo "EEPROM has to be programmed separately"

debug: CFLAGS += -DDEBUG
debug: all

# reset board by setting DTR
# the capacitor on DTR with create a pulse on RESET
# after reset the bootloader is start
# the bootloader can be used to reflash the device
reset:
	stty 57600 raw ignbrk hup < $(PORT)

# flash the device using the internal bootloader
flash: $(TARGET).hex reset
	$(FLASHER) -U flash:w:$(TARGET).hex:i

# write EEPROM on the device
eeprom: $(TARGET)_eeprom.hex reset
	$(FLASHER) -U eeprom:w:$(TARGET)_eeprom.hex:i

# write bootloader and fuses
bootloader:
	wget http://code.google.com/p/arduino/source/browse/trunk/hardware/arduino/bootloaders/atmega/ATmegaBOOT_168_atmega328.hex
	avrdude -p $(DEVICE) -c usbtiny	-U lfuse:w:0xff:m -U hfuse:w:0xda:m -U efuse:w:0x05:m -U flash:w:ATmegaBOOT_168_atmega328.hex:i
	rm ATmegaBOOT_168_atmega328.hex

# create main target firmware
compile: $(TARGET).elf
	$(SIZE) --format=avr --mcu=$(DEVICE) $(TARGET).elf

# compile source files
%.o: %.c %.h
	$(CC) $(CFLAGS) -I. -mmcu=$(DEVICE) -DF_CPU=$(F_CPU) -c -o $@ $<

# link compiled files
%.elf: $(OBJ)
	$(CC) $(LDFLAGS) -I. -mmcu=$(DEVICE) -DF_CPU=$(F_CPU) -Wl,-Map=$(TARGET).map,--cref -o $@ $(OBJ)

# create extended listing for additional information
%.lst: %.elf
	$(OBJDUMP) --section-headers --source $< > $@

# create flashable ihex from firmware
%.hex: %.elf
	$(OBJCOPY) --only-section .text --only-section .data --output-target ihex $< $@

%_eeprom.hex: %.elf
	$(OBJCOPY) --only-section .eeprom --change-section-lma .eeprom=0 --output-target ihex $< $@

clean:
	rm -f $(TARGET) $(TARGET).hex $(TARGET).elf $(TARGET).lst $(TARGET).map $(LST) $(OBJ)