Preonic Compile Firmware QMK QMK support can be found here Burn Firmware $ dfu-tool list $ dfu-util -v -d 0483:df11 -a 0 -s 0x08000000:leave -D preonic_rev3_grumpycat.bin Layout Layer 0: classic alpha Layer 1: punctuation Layer 2: functions and numbers Layer 3: Misc