Finished Firmware, Organized Project, git init

Finished first draft right side firmware for keyboard.

Organized all files for good organization purposes. Uploaded full project to GitHub, updated README. Put together BoM and found links to purchase materials, organized in a separate Google Doc.

I think I'm done!!!

KMK Firmware for Left Side

Maybe finished firmware for left side? Adapting to right side should be light work (to be done later)

Added reactive key rgb effects to key matrix using a subclass of Key class (I hope it works and timer.sleep doesn't pause the entire main loop will fix later). Set up split keyboard and specified Bluetooth connection (Still don't know how this works).

Skipped adding voltage checker for now.

Added picture of subclass and maybe the great errors I have made will be exposed.

Finished the Case

Lowkey not very sure if forgoing mounting screws on the PCB is the smartest idea. I figure that since there is more surface area, the stress should be spread out a little more? I'm worried about damaging traces, but I'm pretty sure the edges are mostly clear.

Screws added for case.

Designed the Case

Tried to make a case that doesn't screw into the PCB, instead clamping it between two 3d printed pieces that are screwed together. Still need to add screws.

Began Case Design

Began designing the case for the PCB. Decided to make a plateless case and order keyswitches with pins. Will make one side of the case and then mirror it.

PCB Adjustments

Created silkscreen images and added them to the PCB. Name of product, XIAO HERE, etc.

Reformatted edge cuts to match the 5mm mouse bites.

Tried to leave places on the PCB free of traces to later add mounting holes. The next step is to design the case in CAD using Fusion360.

Finished Traces for the Right Side of the PCB

Almost identical process to the left side of the PCB. Went much faster this time once I knew which traces to prioritize and which ones to abuse vias on.

Used Design Rules Checker to make sure all correct pads are connected. Make sure that the ground pour doesn't have any isolated copper islands.

The next step is to add funny silkscreen images.

Created Traces for the Left Side of the PCB

Connected all the traces for the left side of the PCB. Wondering if they can be mirrored for the right side, it was a lot of moving stuff around.

Used ground fill, placed many random vias to make sure front and back and all the little copper islands are connected. Might need more.

Defined edge cuts and checked that everything looks about right in KiCAD 3D viewer. Hooray!

Kinda awkward but there was one keyswitch guy backwards when checking 3d viewer. I fixed the jit, and Design Rules Checker would probably have caught it, but remember to be careful out there.

Placed Footprints of the PCB

Switched footprints of LED to reverse mounted SK6812. Now there are 44 LEDs, one for each key.

Placed all the footprints in the PCB manually. Looking back, should have just flipped one side but alas.

Next comes routing all the traces.

Designed Schematics of PCB

Designed the Schematic of the PCB

• XIAO-nRF52840-SMD
• 44 keys total on key matrix, 22 each side
  • Kailh Hotswap CPG151101S11, compactible with MX-style switches
• 42 leds, SK6182 "Neopixels", 21 each side
  • Lowkey not sure if the NFC pins can serve as general purpose pins
• Battery voltage sensor using resistors
  • 806k and 2M ohm resistors

Mouse came in very handy, abuse copy and paste as much as possible. Labels are super busted still.

Leaving mounting holes for screws off the schematic for now. Will see about adding them in once PCB placements are more refined and the foldable case is CADed.