After 100+ hours, 3 AIs, many failed attempts, a lot of resoldering, and almost giving up, I finally built my handwired 40% ortholinear Choc keyboard with a ThinkPad TrackPoint module.
I had built three Corne keyboards before, but this was my first fully custom handwired board. At some point I bought a 3D printer and realized I could design and print a keyboard case exactly how I wanted it. I used Flatboard Generator from GitHub to make a compact ortholinear layout, with the Choc switches as close together as possible so the MBK keycaps would fit nicely, while still keeping the case small enough to fit on my printer.
The first version worked as a normal keyboard after a lot of trial and error with the wiring and QMK firmware. I actually used it as my main keyboard for about two weeks. But I still had the itch to build a keyboard with a TrackPoint.
So I bought two used ThinkPad keyboards and salvaged the TrackPoint modules from them. That part was much harder than I expected. The pins are extremely small and close together, and I destroyed the first module while trying to solder to it. For the second one, I used a multimeter and a lot of help to identify the correct pins.
Getting the TrackPoint working was the hardest part of the whole project. I had many failed QMK builds, wrong wiring, unstable behavior, and moments where I thought the module was dead. Things started improving only after adding the right capacitors and resistors, cleaning up the wiring, and testing again and again.
One of my biggest mistakes was the diode wiring. In the first photo, you can see that I wired the diodes incorrectly. I basically made a chain where one diode leg was soldered directly to the next diode leg, instead of having each diode connect properly to a straight row/column wire. I was very close to stopping the project there, but I removed the bad wiring and redid it using a straight copper wire.
The final result is not the cleanest keyboard in the world, but it works. The switches are Choc, the layout is 40% ortholinear, the case is 3D printed, the firmware is QMK, and the TrackPoint actually works.
This project taught me a lot: handwiring, matrix wiring, diode mistakes, QMK debugging, TrackPoint pin identification, soldering tiny pads, and how many times you can redo the same thing before finally getting it right.
It was frustrating, but now I have a small custom keyboard that I designed, printed, wired, flashed, repaired, and modified myself.
Video: https://imgur.com/a/f0MOF6i
Definitely not perfect, but I’m really happy with it.