Data Sheet

all: $(TARGET).hex

clean:

rm -f *.o *.hex *.obj *.hex

%.hex: %.obj

avr-objcopy -R .eeprom -O ihex $< $@

%.obj: $(OBJECT_FILES)

$(CC) $(CFLAGS) $(OBJECT_FILES) $(LDFLAGS) -o $@

program: $(TARGET).hex

avrdude -p $(MCU) -c avr109 -P $(PORT) -U flash:w:$(TARGET).hex

Make sure that the PORT variable in the Makefile is set to the name of the A-Star’s virtual serial port. In Windows,

\\\\.\\USBSER000 should work if the A-Star is the only USB device connected that is using the usbser.sys driver, but

you can change it to be the actual name of the COM port (e.g. COM13).

In a command prompt, navigate to the directory with the Makefile and main.c. If you run the command make, the code

should get compiled and produce a file named “main.hex”.

Programming

To program the A-Star, you will need to get it into bootloader mode first. One way to do this is to reset the AVR twice

within 750 ms. The A-Star 32U4 Mini boards have a reset button that can be used to reset the board. On any A-Star

board, a pushbutton can be connected between the GND and RST pins to serve as a reset button, or you can use a

wire. Once the A-Star is in bootloader mode, quickly run the command make program to program the A-Star. If you

wait longer than 8 seconds, the A-Star bootloader will exit and the AVR will go back to running the user program.

6. Getting started Page 37 of 47