DIY Midi Controller v1

For this revision I included more encoders, all with pushbuttons and RGB LED’s. The enclosure was sketched in DesignSpark and 3D printed in biodegradable PLA plastic.

The circuit board was drawn in KiCad and printed through OSHPARK. The knobs’ LED pins are wired to WS2811 chips, turning the 18 led cathodes into 6 addressable “neopixels”. From that point the 6 encoders lights can be controlled individually from one port on the Teensy 3.2. The ws2811 chips are also fantastic as they are easily controlled through various neopixel libraries.

The code involved was very similar to the code used in the first revision, slightly optimized to read all of the encoders quickly.

I got the box sending nice and smooth relative signed bit midi CCs to ableton and MAX/MSP, but the light controls still aren’t working. My initial circuit board has too small a footprint for the ws2811 chips I have… A crushing oversight but part of the design process I am told.

Without the ws2811′s in place I got the box functioning nicely as a midi controller alongside a generative synthesis max patch. I showcased this at another Lab open house and really enjoyed seeing people twist away. Scaling the values that were spat out and restricting them to musically interesting ranges made it possible for children and non musicians to explore synthesis with no previous knowledge or conception of how it should work.

The ‘black box’ synthesizer concept is becoming more intriguing to me. I can see this being developed further into a self contained digital synthesizer that is endlessly generative and allows users to sculpt the sound without labels or instructions. From an artists point of view it’s an exciting collaboration between my sonic preferences and a non-musician’s actions and preferences.

Before that happens I need to order a revised circuit board…

Project files are available here under a creative commons 3.0 license:

https://github.com/qjarvisholland/rgb-rotary-to-midi

Special thanks to Paul @ PJRC, PCC interactive lab, Jesse Mejia, Lady Ada, and Darcy Neal