MusicRadar

Roland’s Go:Mixer Studio could be the perfect portable mixer and audio/MIDI interface for your iOS devices, and you might be tempted to use it in your studio, too

So now, after a couple of Go:Mixer Pro devices, Roland has introduced its most comprehensive model yet: the Go:Mixer Studio.
GitHub

A simple to build USB midi controller.

Please note that the V2 of this controller can be bought as a complete set with better components, a pre assembled PCB and much more on my tindie: https://www.tindie ...