I made a series of ergonomic keyboards called Ergopi that use the Pi Pico as their controller, and run the KMK firmware. I plan to upload the PCB files to Github, as I believe there should be more keyboards that use CircuitPython – SouthPawEngineer.
There are three sizes of Ergopi keyboard – with differences like a number row and outer column. Beside that, all of them use low profile Choc switches, an EC11/EC12 rotary encoder, and the largest board also has a 5-way switch.
The diodes are standard 1N4148 diodes, in either the common through-hole DO-35 package or SOD-123 surface mount package. They all come with some nice extras -– you can add RGB underglow with WS2812B LED’s (5050 package) and a small speaker on the underside of the board.
The three sizes have 60, 48 and 40 keys, respectively. SouthPawEngineer uses them plateless, but you can also flip the controller over, mount it on the underside, and use a plate instead.
In not just the designer's opinion, the RP2040/Pico/KMK workflow is so much easier compared to everything else available for DIY keyboard builders. All you need to change your keymap is editing a simple text file on your device (appearing as a USB drive).
No need of any Github wizardry, bothering with setting up the local development environment, and using AVRDude/Dudess – which, for some reason, hangs for about two minutes before doing its job (on Windows). In addition, you can add new functionality with simple Python code.
I’ve found a lot of joy from being able to change things at will and update my keyboard in less than five seconds. Why use the Raspberry Pi Pico? Because it’s powerful, easy to get a hold of, and very affordable at $4 USD – SouthPawEngineer.