Cheapino
Probably one of the cheapest split keyboards you can build.
This is the result of really enjoying building keyboards, but not wanting to spend that much money on it. The pcb is reversible, connected using rj45, and utilizes a japanese duplex matrix, so only one mcu is needed(in fact it only uses 7 of the rj45 wires to support 18 switches and an encoder on the right side).
Checkout the build guide for more details and pictures.
If you just want to flash Miryoku on your Cheapino, download the uf2 file from the release section, put the rp2040-zero in dfu mode by holding boot while pressing reset, then return, then you should get a new usb drive which you can just copy the uf2 file to.
A qmk branch with support is located here: https://github.com/tompi/qmk_firmware/tree/cheapino
If you are wondering if this is actually usable, Im writing this on it, and Im pretty happy with it. My son is also using his at his work and claims its very usable.
These are a few other people that built it:
https://www.reddit.com/r/ErgoMechKeyboards/comments/12xg4u7/built_the_cheapino/
https://www.reddit.com/r/ErgoMechKeyboards/comments/13c274r/cheapino_build/
https://discuss.tchncs.de/post/410101
https://discuss.tchncs.de/post/852362
https://lemmy.world/post/2080485
https://lemmy.world/post/2832967
https://lemmy.world/post/2480447
Printable file for the case here: https://www.printables.com/model/541536-cheapino-case-with-basic-tenting
@keyboard-magpie made a plate which will help position the switches: plate.stl
Drawbacks:
- Without a plate, its pretty difficult to solder swithes straight. I made a small helper "fork" to hold each column in place when soldering.
- RJ45 cables are a bit rigid, so they do not lay down on the table nicely like audio cables.
- There is no official qmk support, you need to compile from my branch manually... Keymap can be edited in qmk configurator though.
