We’re always amazed at the restless minds of makers in the Raspberry Pi community and today we’re sharing a super cool — and dare we say groovy — synthesizer mod from Blitz City DIY. In a recent post shared to Twitter, she shared a musical demo of a MIDI synth that relies on the tiniest RP2040 powered we've seen, Adafruit's QT Py RP2040.
In this project, keyboard input is handled by an Oskiton Scout synth—a 17-key synth kit intended for Arduino compatibility. Instead of using an Arduino, MIDI output is transmitted to a QT Py RP2040 running CircuitPython via UART.
According to Blitz City DIY, the QT Py RP2040 is using CircuitPython to interpret the MIDI input from the Oskiton Scout and sends the data over to a Raspberry Pi 3 B+ via USB. CircuitPython has a dedicated library for working with MIDI, and when used with the tiny $10 QT Py RP2040 we have an exceptionally simple means to add MIDI to any computer.
The code for the project mixes MIDI notes, a numerical value which represents the musical note, with a duration to play a note for a set time. Looking further into the code we can see that each note is also represented by a color, shone from the NeoPixel found in the Oskiton Scout synth. So play a note, and watch the synth "play a color". To get a closer look at the code used in this project, check out the official Blitz City DIY page at GitHub.
This isn’t the first Raspberry Pi project we’ve covered that dabbles in the world of MIDI-based input. In the past, we’ve seen a Raspberry Pi Pico-powered MIDI converter for guitar and a full-sized Pi used to add MIDI support to a Korg Monotron synth.
If you don't already know MIDI (Musical Instrument Digital Interface) is a means for computers and instruments to communicate between each other. MIDI was made popular in the 1980s and 90s by musicians wishing to experiment with the rising home computer scene. An example of which is the Atari ST, a 16-bit computer with built in MIDI that could change the sound of instruments and issue a complex series of instructions to a sequencer.
Check out the original thread shared to Twitter for a demo video of the MIDI synth in action and be sure to follow Blitz City DIY for more cool Pi projects.