The world of DIY mechanical keyboards is full of niche devices with unique designs, and more than a few gimmicks. Keybytes, a new project by a modder who goes by notaroomba on GitHub via KBDnews, falls somewhere between the former and the latter, and mostly serves as an interesting proof of concept. Keybytes a modular mechanical keyboard project designed for ultimate customization. The basic idea is to have single mechanical keyboard sockets with full-height MX mechanical switches, aka Keybits, each with their own PCB and magnetic connectors that allow them to snap together, effectively creating an infinitely reconfigurable keyboard.

The whole project hinges on the Keyword, a motherboard of sorts that contains the USB Type-C port, battery charging circuitry, and a STM32WB55 MCU. That motherboard connects to each Keybit, each of which also has its own RISC-V CH592F MCU and some clever tricks that allow the bits to connect in a rotation-agnostic way. There are also alternative PCB options, including one with a 3-axis Hall sensor, which would allow for something like a joystick or Hall effect switch implementation, and there are also spacer Keybits with power passthrough in 1u, 0.75u, and 0.5u units. In the latest design revision, each of the Keybits also has six magnets per side and automatic polarity detection, meaning switches can be arranged in-line or at 25%, 50%, or 75% offsets.

Key features:

• Rearrangeable layout where every key is its own 1u PCB
• CH592F RISC-V microcontroller with BLE and USB on every key
• Cross shaped 2 layer flex PCB that folds up into the case, with FR4 stiffeners
• Magnet contacts on all 4 sides, 6 per side (1x2mm N52) on a 2.38 mm grid
• Any rotation and 0/25/50/75% stagger between keys
• Polarity independent sides, a small FET bridge on each side sorts out VBUS and GND
• WS2812 RGB LED on every key
• Mill-Max 3305 hot swap sockets
• Hall variant with a TMAG3001 3-axis hall sensor, so the same board can be a hall key, a knob or a joystick
• Keyword main board with a CH592F, BLE and USB-C
• Battery charging with the BQ25185 for a small LiPo
• USB-C with ESD protection (USBLC 6)
• Pogo pin flashing of every Keybit from the Keyword, then OTA updates
• Flex spacers (1u, 0.75u and 0.5u) to pass power across gaps