Hello!
I’ve been scratching a design for my new keyboard and wanted to try something fun. It’s gonna be a 34-key unibody split, but I thought it would be cool to use the space in the middle for something fun. Many parts like cirque touchpads, roller encoders and such are hard to obtain in my area, so I didn’t bother. Then I found a post by LazaroFilm with a small smartwatch LCD made by WaveShare and thought it would be a fun idea. I browsed their catalogue and noticed that none of the models are ideal for the job. The RP2040 touch LCD lacks GPIO and mounting points, the RP2040 LCD is pretty cool, but not having touch support is a bummer. Finally I thought that maybe it’s better to go with a separate controller like a pico, and an 1.28" Round Touch LCD. It has touch support (duh) and 4 mounting screw posts. Pretty good. My only issue is the 13 pin JST connector used to hook it up to an MCU. It’s gonna be a PCB design, no hand wiring, so I don’t want a mess of cables dangling around. If only I was able to hook up a goldpin connector, or something, it would come together pretty clean. I was toying around with an idea of designing an adapter board, but there’s not much room to play with and the pins are pretty tightly spaced (1.25mm). Also, it would be really great to come up with something that can be easily done without special equipment. All I have is a soldering station. No hot air, no nothing. I’d love to be able to design something that anyone can make at their desk.
I’d be grateful for any clever ideas. Thanks in advance! Cheers!
You could desolder the JST connector and solder on a 13 or 14 pin FFC connector onto it and then use a small FFC jumper to connect it to your board. The cleanest solution if you can't take off the screen and re-design the PCB electronics on your keyboard PCB.
Second idea you could do is use Pogo pins on your PCB, desolder the JST header, then you can use the mounting screws to put a bit of pressure on the Pogo pins for a good connection. You can use SMD or through-hole and put the end of the stem embedded in your non-conductive case (easier for alignment than SMD)