What is it?

Pico Keys is an open-source multitrack polyphonic MIDI sequencer and synthesizer kit for the Raspberry Pi Pico. Raspberry Pi Pico not provided in the kit!

The digital synthesizer is based on Mutable Instruments' Braids code, which means plenty of different sounds available. There are 3 synthesis tracks available, the first one has 3 voices polyphony, the other two are monophonic.

You can also control the synthesizer from external MIDI gear, or control external gear with the internal sequencers and arpeggiators.

This is with the stock firmware, but Pico Keys is also a hacking machine that you can for instance program with CircuitPython to make a sampler.

Why did you make it?

My first goal was to make a powerful MIDI keyboard using mechanical switches like the Kailh Choc. MIDI keyboards on the market offer either a sequencer or an arpeggiator, sometime both but not usable at the same time. I wanted a keyboard that would provide multiple sequencers and arpeggiators to create "complex" parts from a single device. This was the version 1 of the Pico Keys.

I then realized that digital audio synthesis was possible without adding too much complexity to the hardware design. And here we are with version 2.

Kit content

The kit contains:

• A pre-assembled Pico Keys PCB
• Brown Kailh Choc switches
• Clear switches caps

An optional enclosure is available.

Assembly

The only assembly required is to solder a Raspberry Pi Pico (not included) to the back of the PCB.

Install the Pico Keys software

1. Get the picoprobe .uf2 binary from our release here

2. Hold the BOOTSEL button on the Pico, then connect to your computer using a micro USB cable.

3. Drag and drop the UF2 file on to the RPI-RP2 drive.

4. You should be good to go.

Enclosure

A 3D printed resin enclosure is available as an option. When exposed to sunlight the resin will yellow, for this reason we recommend painting the enclosure.