Zynthian is an Open Synth Platform based in Raspberry Pi, Linux (Raspbian) and some Open Software Synthesizers.
This repository contains the stuff for building a MIDI-USB controller for the Zynthian Platform. The current design has 8 rotary encoders with led-ring controlled with an Arduino-like board (SparkFun ATmega32U4). The firmware allows to control upto 24 MIDI-CC parameters (3 layers: red, green, blue).
You can learn more about the Zynthian Project reading the blog or visiting the website. Also, you can join the conversation in the forum.