First thing I had to do was get as much space as possible, so to that end, I built a hand-wired keyboard with a raspberry pi pico as the micro controller.

I used this blog post as a guide. Everything went fairly smoothly. The biggest hurdle was that I used solid-core wire for the matrix, thinking it would make positioning the wire easier, and it did, but it also meant I broke a lot of connections as I manhandled the board later on, and had to re-solder a bunch. Also cutting the insulation with a hobby knife was tedious but worth it.

I used low profile gateron switches (which have a non-standard pin layout, but that didn't matter for hand-wiring) and low profile keycaps to get as much space as possible. The plate/keycap assembly is mounted to the board with a strip of velcro on each side, and the wires are kept in place with velcro loops.

Green wire was chosen to fit the theme of bamboo.

Despite getting the pico a little crooked, and having to use keycaps where they fit and not necessarily where the legends match the function, it turned out pretty well, I think. Still tinkering with the layout (which is done with QMK and VIA)

With the velcro mounting, plate, switches, and keycaps, the keyboard takes up about 16 mm, so I have roughly 9 mm of height left to work with in the lid. According to the data sheet, the LCD module is 11mm. Hmm. I'd like the keys to not be pushed in while the lid is on, but that might not be feasible. Also might have to re-think mounting for the main keyboard assembly as the velcro is surprisingly thick when put together (~3mm or so).