OSHW-DEIMOS/SOFTWARE/A64-TERES/TERES-KBD-RELEASE/Keyboard_firmware/README.md

Factory default firmware. Burn it with AVR-ISP500(-TINY) using avrdude and command:

avrdude -V -pm32u4 -cstk500v2 -P/dev/ttyACM0 -U flash:w:keyboard.hex:a -U hfuse:w:0xD8:m -U efuse:w:0xC7:m -U lock:w:0xCF:m

or any ATmega32U4-compatible programmer tool and software.