Raspberry Pi & Pd Synth

Pi Synth

This is a DIY synthesizer that uses a Raspberry Pi 4 computer with 8 GB of RAM, Python 3, and Pure Data along with various potentiometers, buttons, and an LCD. The synth uses Pd patches as the sound source and provides a menu on startup for a player to select which Pd patch to load for performance. This is an upgraded version of an original synth I built in 2015 using a Raspberry Pi 2 computer.

I like that this is a relatively inexpensive instrument that makes us of open source technology and software. It is simple in its design and purpose. The lack of fancy controls and the limitations created by running on a less powerful computing platform are perks to me as a computer musician / improviser. The instrument’s limitations posit a sound world that is unique and different from a world using my MacBook Pro and a more CPU hungry patch. I like when there are limitations and fewer possibilities in scale considering the almost limitless sound possibilities available in most commercial software.

All of the components inside the box were soldered by hand and the circuits to transduce the knobs and buttons are very simple. Even so, the inside of the box is still a bit of a wired mess. If I ever find the time to continue down what I call the Pi Wormhole (TM) my thought is to print simple PCBs and make a basic kit. We’ll see . . .

UPDATE – November 11th 2022!

I recently updated the Pi Synth to make use of Cycling74’s RNBO objects and compiler. I can now use Max/MSP patches to create sounds and pieces on the Pi Synth which opens up a simpler, and more broad sound world from that of Pd. Switching to RNBO provided an option for me to update the Python script that handles the buttons, knobs, and LCD on the synth and now the Python code is more efficient and accurate.

Here is a short improvisation using the synth and a recording of a harpsichord:

Below is a basic overview of using RNBO and a brief demo of a RNBO granulator patch.

Pure Data Videos (older)