Raspberry Pi Pico Keeps Unicomp Keyboards Clicking

Unicomp Controller Cards
(Image credit: Admiral Shark's Keyboards)

With the discontinuation of a crucial chip in its controller cards, Unicomp's range of Model M keyboards could have been done for. Even the best mechanical keyboards need a good supply of chips. So, in comes the Raspberry Pi Pico to save the day. According to Admiral Shark's Keyboards, via Adafruit, it seems that recent models now feature our favorite microcontroller instead of the discontinued part.

The discontinued part was a Cypress CY8C24493-24 programmable embedded system-on-chip used in Unicomp's Ruffian and AP1 controller cards. Discontinuing this functional chip forced Unicomp to redesign all its USB controllers, but this time using the Raspberry Pi Pico. It was a mix of affordability and availability which sealed the deal. But also the ability to reprogram and mod your Model M with new RP2040 powered controller cards, Aristides (replacing Ruffian) and Justify/Mike Smith (replacing AP1).

The older controller cards, sporting the Cypress CY8C24493-24, never received custom firmware. There were no open-source toolchains, no built-in USB bootloader and QMK did not support Cypress chips. Purdea Andrei has ported Vial-QMK to the new Unicomp controller cards running the Raspberry Pi Pico. With this port, one can reconfigure their keyboard in real-time using a GUI or a JSON configuration file. The user can create layers that change the functionality of a keyboard (from standard typing to enhanced function keys), and create macros and combos to automate monotonous tasks.

If you purchased a Unicomp Model M from June 2023 onwards, chances are you have a Raspberry Pi Pico working under the keys. If you have an older keyboard, replacing the controller with a Raspberry Pi Pico-powered alternative is possible. But you will need to do your homework. Handily, Admiral Shark's Keyboards has a list of models that should be compatible.

As of today, all Unicomp keyboards (except for EnduraPro) should come with an Aristides controller card. Mini M models destined for the United States are shipping with Justify/Mike Smith controller cards.

If you are unsure, you can open up your keyboard and take a peek at the controller. There is no mistaking the Raspberry Pi Pico. If you don't fancy cracking the case, follow this guide to determine the controller.

Adafruit notes in its blog post that it would be interesting to see models running the Raspberry Pi Pico W running custom firmware for Bluetooth connectivity. We agree and would love to see Bluetooth Model M keyboards on our best wireless keyboards page.

Les Pounder

Les Pounder is an associate editor at Tom's Hardware. He is a creative technologist and for seven years has created projects to educate and inspire minds both young and old. He has worked with the Raspberry Pi Foundation to write and deliver their teacher training program "Picademy".