An alternative controler for the HHKB designed by hasu.
Keyboard Maintainer: QMK Community
Hardware Supported: HHKB Alternate Controller
Hardware Availability: https://geekhack.org/index.php?topic=12047.0
Make example for this keyboard (after setting up your build environment):
make hhkb:default
See build environment setup then the make instructions for more information.