export CC = avr-gcc
  
  export MCU = atmega328p
  export TARGET_ARCH = -mmcu=$(MCU)
  
  export CFLAGS =  -Wall -I. -DF_CPU=16000000 -Os #-g
  export LDFLAGS = -g $(TARGET_ARCH) -lm -Wl,--gc-sections #	-Os
  
  TARGET = usb
  TERM = /dev/ttyACM0
  CPPFLAGS = -mmcu=$(MCU)
  PGMERISP = -c stk500v1 -b 115200 -P $(TERM)
  ARVDUDECONF= -C /usr/local/arduino/arduino-0022/hardware/tools/avrdude.conf
  export DUDE = /usr/bin/avrdude -F -v -p $(MCU) $(AVRDUDECONF)
  
  C_SRC = $(wildcard *.c)
  OBJS = $(C_SRC:.c=.o)
  
  all: $(TARGET).hex
  
  clean:
  	rm -f *.o *.hex *.elf
  
  %.o:%.c
  	$(CC) -c $(CPPFLAGS) $(CFLAGS) $< -o $@
  
  $(TARGET).elf: $(OBJS)
  	$(CC) $(LDFLAGS) -o $@ $(OBJS)
  
  $(TARGET).hex: $(TARGET).elf
  	avr-objcopy -j .text -j .data -O ihex $(TARGET).elf $(TARGET).hex
  	avr-objcopy -j .eeprom --set-section-flags=.eeprom="alloc,load" --change-section-lma .eeprom=0 -O ihex $(TARGET).elf eeprom.hex
  
  upload: $(TARGET).hex
  	stty -F $(TERM) hupcl # reset
  	$(DUDE) $(PGMERISP) -U flash:w:$(TARGET).hex

  	make clean