SonoPad

Devlog #3 Finished modeling the case and customizing the firmware for basic use. For the case I went with 15 degree tilt and simple design to be printed in two parts: base, and plate. Holes inside line up with the PCB’s drilled holes for alignment if needed. The back hole for usb c connection is intentionally left big for this first iteration to allow for better alignment and will be cleaned up later. A knob for the rotary encoder also needs to be made once I have the exact physical measurements I need to ensure there are no collisions. For the firmware I used QMK and customized my own keyboard and keymapings. Right now this is just basic and only accounts for the switches. The oled and rotary encoder will be added in another commit.

Devlog #2

First iteration of the PCB layout is done. I went with a 2x4 layout of keys to allow enough pins for the screen and rotary encoder peripherals.

The plan is for the screen to display some useful information about the sound or some graphic. The rotary encoder should be useful for volume control of different applications. The rest of the keys will likely just be fore shortcuts or pause/play on music.

As for this pcb layout I went with the screen and the xiao overlapping for space with the xiao being mounted on the back of the board. I’m hoping that if I solder headers to raise the xiao and the screen away from the board they wont interfere with one another, but it might be tricky to solder. The copper pour on the back layer makes ground connections really easy and should improve emi but I doubt it would cause much trouble if left out. I’m pretty sure the diodes should fit below the keycaps and not physically interfere but we’ll see

The Place Footprints plugin for Kicad makes placing the button matrix so much easier I would recommend checking it out for this project.

Devlog #1
Finished the Schematic a few days ago but updated to improve readability and pin assignments on the XIAO