Assembly instructions
To assemble the device, start by 3d printing the shell, which can be found at /case/case.stl in this repository. I would reccomend doing this with some kind of high precision setting on your printer - my first print used the Draft quality with layer height of 0.2mm, but my second used 0.08mm and it looked a lot better. I just printed this on my school’s Bambu Lab P1S printer. Here’s how it looks, printed in white on this 0.08mm setting.
Next, you’ll need to solder the buttons to the PCB that you’ve got printed and assembled. Get 6 generic push button push to make switches, and solder them into the holes on the pcb. Get the battery (no smaller than 500mAh), strip the JST connector off it if it has one, and solder the positive and negative lines to the copper pads of the board as indicated below:
Key: Battery as indicated, positive to J4, negative to J3. Make sure these lines do not touch.
Switches: solder legs to tht holes for SW2-SW7, as highlighted in yellow.
Next, get your screen and solder it to the screen connector at the top of the PCB. The leftmost pin, from the front of the board, is the BL pin, with GND on the far right. This means that I had to mount the specific display I bought from aliexpress upside down, and flip all the coordinates in software.
Once you’ve done that, the device is pretty much ready to go. Slot the whole contraption into the 3d printed case - the case is designed so that the battery goes behind the screen and then the wires for the battery come down and snake through the little notch to the left of the battery compartment. There are four posts on the lower section of the case, which you can use to hold the PCB in place through the circular holes on each corner of the PCB.
If you leave it like that, it will work, but depending on the sizes of all your components, everything will probably rattle and tilt and slide around a ton. I solved this problem by liberally applying small bits of furniture skates, double sided tape, and foam to hold everything in place. This is something that I can probably improve on in version two of the system.
From there, all you’ll need to do is to load the code onto the thing. Plug it in via USB C to your computer, and drag the compiled UF2 file from the compilation instructions below onto the drive that shows up on your file explorer. It’ll reboot into the menu, and you’re ready to go.