What is it?

It's a printed circuit board, which can be used to build a portable computer keyboard.

It's black and 1.6mm thick, with a minimal set of markings to help with assembly and testing.

All parts are through-hole mounted, so it's easy and great practice for anyone new to soldering.

You'll need the following additional parts:

• Raspberry Pi Pico (or Pico W if you want to try adding bluetooth support -- I haven't tried this)

• Header pins to connect the Pico to the board

• 48x keyswitches, with Cherry MX footprint

• 48x keycaps for your keyswitches

• 48x diodes (regular small kind such as 1N4148) so that each key can be detected individually

• Optional LED and resistor for indicator in front of Pico board

• Optional LED and resistor for hardwired power indicator (beneath Pico board)

• Some kind of base to go under the board. I'd recommend using a dense packaging foam.

Why did you make it?

I wanted a board design that was ergonomic enough to use all day, but compact enough to fit in a regular sized rucksack for use on the go. It sits quite well on top of a laptop's built-in keyboard to serve as a replacement.

At the time I was having pretty serious wrist pain from bad habits twisting around to use the arrow keys on the laptop. This has solved that problem and I've since developed a strong preference for this kind of minimal 48-key design.

What makes it special?

It's based on a Raspberry Pi Pico, so it can be programmed in CircuitPython instead of customizing QMK. (I think this is fun and good, but others might disagree.)

Note that the first similar board that I built years ago (looking around online for something like this) was a PCB from Troy Fletcher, and all my keyboards since (including this one) have been personalized attempts to perfect the implementation (from my perspective) while maintaining the same vibe and concept. You may prefer his designs, and they are certainly less expensive to ship if you're in America!

In this design, I've included his idea of multiple possible switch positions in each column, so that the keyboard can be customized to fit your finger lengths.