3D render of a long thin green PCB with a ball-grid microcontroller, a USB-C port and a row of connector pads

PCB designPart 4 of 4Drawing 16.4 of 47

Version 4

Built around a Touch Bar, split into five boards, with snap-on numpad and trackpad modules.

StatusProduction, 2026. Version two built, version four drawn
Layout75%, 84 keys, hotswap Kailh Choc sockets
Version twoSTM32F072 over USB-C, QMK with VIA, all 84 keys tested
Version threeper-key RGB, moving from wireless to wired
Version fourTouch Bar, five PCBs, trackpad and numpad modules
Softwaremy own Keyboard Editor app for remapping

Sheet 02 of 05/Gen four

Built around a Touch Bar

The fourth keyboard is built around one rule: the Touch Bar must always work. It uses the panel from a MacBook Pro Touch Bar on its own small board above the function row, and the touch side is something I'm reverse engineering myself.

3D render of a small dense green PCB with a silver radio module, two white connectors and many small chips — *PL 09*The main board, 44 by 34 mm, with the Bluetooth module and all of the battery electronics.

Sheet 03 of 05/Five boards

Five boards instead of one

Version four splits into five PCBs. The main board holds the Bluetooth chip and the battery electronics, the keyboard board has its own chip for the keys and lights, and the Touch Bar, trackpad and numpad each get their own board.

3D render of a wide green keyboard PCB with rows of hotswap switch footprints — *PL 10*The keyboard board: 84 switches, 84 diodes and an LED under every key.

3D render of a numpad PCB with seventeen switch footprints in four columns and pogo pin pads on the sides — *PL 11*The 17-key numpad module, the one board that is fully routed with no errors.

Sheet 04 of 05/Modules

Snap-on modules

The numpad and the trackpad snap onto the side with magnets, and each one also works on its own over USB-C. The trackpad is meant to be at least as big as Apple's Magic Trackpad, with a force-sensing click and a haptic motor.

3D render of a large square PCB covered edge to edge in a diamond-pattern capacitive sensor grid — *PL 12*The trackpad module's sensor grid, sized to match Apple's Magic Trackpad.

Sheet 05 of 05/Gen4 status

Where it stands

Nothing for version four is ordered yet. The numpad board is fully routed, and the others still have open connections. The plan is to make the Touch Bar board first and test it before ordering the rest.