Adafruit Designed an RP2040-Based Development Board Specifically for Custom Keyboards

To many people, computer keyboards are appliances and nothing more — like a toaster or an alarm clock. But there are a lot of us who take our keyboards very seriously. We care about the feel of our key switches and the layout of the keys. To accommodate our tastes, we can either purchase a purpose-built mechanical keyboard or build one ourselves. If you want to go the latter route, then you will need a microcontroller to monitor your keyboard matrix and send key presses to your computer. To make the new RP2040 microcontroller accessible to keyboard builders, Adafruit has designed a new development board with the Arduino Pro Micro form factor.

The RP2040 is the microcontroller found in the new Raspberry Pi Pico development board. It is both powerful and affordable, but the Pico has a unique footprint and pinout. That means that it isn't directly compatible with existing custom keyboard PCBs. This new board from Adafruit, called the KB2040, gives keyboard builders the power of the RP2040 microcontroller in a familiar form factor. Many keyboard PCBs intended for custom builds are designed to accept the Arduino-compatible SparkFun Pro Micro or Elite-C development boards, which share the same pin layout. The KB2040 has that same pin layout, so it is compatible with the same keyboard PCBs.

The KB2040 offers a few advantages over both the Pro Micro and the Elite-C. Those boards utilize the Microchip ATmega32U4 microcontroller, but the RP2040 is far more powerful. And, though it is currently difficult to buy bare RP2040 chips, they will be very affordable once supply catches up to demand. Most importantly, the KB2040 lets you take advantage of Adafruit's fantastic CircuitPython to program the keyboard's behavior. The KB2040 even gives you some nice features like an onboard NeoPixel RGB LED, a boot-select button, and 8MB of QSPI flash memory.

It is unclear if Adafruit will be selling the KB2040 or if they will publish the PCB design files so that users can make their own boards. But they have designed the board to make the latter as easy as possible. The PCB only requires two layers, which keeps costs down. Unfortunately, the capacitors and resistors are 0402 size, so they are difficult to solder. But the ground plane has a lot of coverage and that should negate RF interference. Be sure to follow us here at Hackster and Adafruit's blog if you want to find out as soon as more details about the KB2040 become available.