- Install
avr-gcc
(version 9.4.0 used during development) andavrdude
. - Compile code:
$ make
-
Put keyboarder into DFU mode:
- Disconnect keyboarder from usb.
- Press and hold shrug key.
- Connect keyboarder to usb while holding shrug key.
New USB device named
ATm32U4DFU
should appear. -
Flash code to keyboarder:
$ make flash
Official AVR USB DFU bootloader in "Embedded Software" section.