Re:SofleKeyboard – A split keyboard based on Lily58, Crkbd a...
by tzarc on Monday July 22, 2024 @08:35PM
(#41041345)
https://wiki.ai03.com/ is what a lot of people use. Though it's probably easier nowadays to use an RP2040-based ProMicro form factor daughterboard so you only need to handle key placement.
Firmware... QMK: https://github.com/qmk/qmk_firmware/ || https://docs.qmk.fm/porting_your_keyboard_to_qmk
Disclaimer: I'm a QMK Maintainer.