Support for Alternative Layouts
This is a summary of how alternative layouts have been supported by kits such as Colevrak and Homing. It is not a discussion of alt layout performance and development, but if that interests you I highly recommend starting with Pascal Getreuer’s A guide to alt keyboard layouts (why, how, which one?). It’s a concise and comprehensive overview with links to some great sites that go deeper. He also has a separate Links about keyboards page. The Keyboard layouts doc he recommends explains layout goals and metrics in detail, summarizing the alt layouts discussed here as well as more than one hundred others. Sculpted-profile The majority of custom keycap sets are sculpted-profile (Cherry, SA, MT3, KAT, etc. - more on profiles generally here) so let’s start there. Because each row has a unique keycap shape, alt layouts require a unique keycap for each legend that moves off its QWERTY row. At first there were two The Dvorak layout was patented in 1936 by August Dvorak & William L....
Apr 23, 2024
The multiplexer is a pair of TI pca9555rger connected over I2C for a total of 32 pins.
That's as far as I got. I asked at the GitHub repo for a source for dev boards, no response so far. They provide schematics so in theory you could get some PCBs made in low volumes.
Hope this helps.
http://www.ti.com/lit/ds/symlink/pca9555.pdf
There's two of them, basically you have to scan them sequentially and read the state of the pins specified and put that into the matrix data structure and I think QMK will take care of the rest. This means implementing matrix.c::matrix_scan and calling the i2c code from there which stuffs that array matrix with bits related to key presses.