Show HN: A Truly Modular Keyboard

A truly modular keyboard with rearrangeable keys, magnetic cases and Bluetooth!

Key Features • Video Demo • PCB • Case • Credits • License

keybytes-demo.mp4

Key Features

Rearrangeable layout where every key is its own 1u PCB

CH32V003 RISC-V microcontroller on every key

STM32WB55RGV6 main board with Bluetooth and USB

Pogo pins on all 4 sides of every key for power and I2C

Magnetic cases to hold the modules together

Key programming from the main board over pogo pins

2MB QSPI flash (W25Q16JV) to store the key firmware

Battery charging with the BQ25895 and solder pads for a 1S LiPo

Buck-Boost converter (TPS631000)

RGB status LED

USB-C with ESD protection

Ceramic Bluetooth antenna

PCB

Designed in KiCad! There are two boards, the Keybit and the Keyword, and both are 1u (19.05mm x 19.05mm).

A single key with a Cherry MX switch and a CH32V003. Every side has pogo pins for 3.3V, GND and I2C so it can connect to the keyword or to other keybits, and the pads on the corners are for programming.

The main board that the keybits connect to. It is split into two PCBs that stack on top of each other. The top one has the STM32WB55RGV6, the antenna and the flash, and the bottom one has the USB-C, the charger and the buck-boost converter. The 3 pogo pins on the top are for programming the keybits.

Custom designed cases in Onshape, the STEP files are in the cad folder.

Ember - A USB-C powered reflow hotplate with Bluetooth

Cyberboard - A Raspberry Pi Pico-sized STM32 development board with Bluetooth

Trace - A comprehensive PCB ruler with reference footprints

Linea - An EMR tablet

License

MIT