Keybytes Modular Keyboard: RISC-V Chip in Every Key

Most "modular" keyboards let you swap keycaps or switches. Keybytes goes much further. In this open-source project, every single key is its own tiny circuit board with its own RISC-V microcontroller, and the keys snap together magnetically in any layout you like. The project, built by MIT student Nathan Alspaugh and covered by The Register on October 26, 2026, is a delightful example of how cheap microcontrollers are changing what hobbyists can build.

• Per-key brains: each 1u key (19.05 x 19.05 mm) carries a Cherry MX switch and a WCH CH32V003 RISC-V microcontroller
• Connections: pogo pins on all four sides carry 3.3V power, ground and I2C between keys, held together by magnetic cases
• Controller: an STM32WB55RGV6 "Keyword" board adds Bluetooth, USB-C, a LiPo charger and 2MB of flash for key firmware
• License and cost: MIT-licensed on GitHub; a full-size board would cost around $900 with factory assembly, according to The Register

How Does the Keybytes Keyboard Work?

The design splits into two board types, both the size of a standard key. The "Keybit" is a single key: a Cherry MX switch on top of a CH32V003, a low-cost 32-bit RISC-V MCU. Every edge has pogo pins, so a Keybit can connect to the controller or to its neighbors, and corner pads handle programming.

The "Keyword" is the brain. It is two stacked PCBs: the top layer holds the STM32WB55RGV6 with its ceramic Bluetooth antenna and a W25Q16JV 2MB QSPI flash chip that stores firmware for the keys, while the bottom layer carries USB-C with ESD protection, a BQ25895 battery charger with pads for a single-cell LiPo, and a TPS631000 buck-boost converter. Three pogo pins on top let the controller program each Keybit directly, so you never have to hook up a separate programmer to rearrange your layout.

Magnetic 3D-printed cases, designed in Onshape with STEP files in the repository, hold everything together. Pull a key off, move it somewhere else, and the I2C bus carries on.

What Does It Cost to Build One?

The Register reviewed the shopping cart in Alspaugh's project journal. Individual Keybit boards cost only a couple of dollars each, while Keyword controller boards run about $30 apiece. Factory assembly added $69 for the Keybits and $203 for the Keywords. Scaling that to a full-size layout lands around $900, which is why Alspaugh notes he would hand-solder a full build himself.

He told The Register he has spent around 100 hours on the project, and that anyone with the components could probably assemble one in a few days, not counting PCB shipping. He is also considering selling kits once the design is finalized, possibly with new key types such as a fingerprint-sensor module.

Why This Maker Project Matters

Keybytes shows how far the CH32V003 has pushed down the cost of embedding a real processor anywhere, a trend we have followed through WCH's growing lineup, including the CH32V467 RISC-V MCU with Ethernet. When a microcontroller costs less than the switch it sits under, giving every key its own intelligence stops being absurd and starts being a platform. Alspaugh credits Hack Club's Forge program among the project's tools, and all of the KiCad files are public, so others can learn from the design or build their own.

The full repository, including schematics, layouts and the case files, is on GitHub now. For more open hardware and single-board builds, explore our mini computers section.

Sources: Keybytes on GitHub — accessed October 27, 2026; The Register — October 26, 2026; Tom's Hardware — October 27, 2026.