I made this USB-MIDI motor controller shield with DC barrel jacks to simplify musical robotics and kinetic art projects. It has 12 DC outputs controlled by MIDI note messages. 5 of the 12 DC outputs can control motor speed with continuous controller messages. There are four servo outputs which are also controllable with continuous controller messages. Two separate power inputs make it possible to control devices that work at different voltages from the same board. It also has two 1/4" jack inputs for pedals or knobs.

The source code, schematic, PCB layout, and more information about the project can be found here: http://bryanjacobsmusic.com/phout12.html
I put together some kits to eliminate the complications of sourcing parts. You can pick one up here: https://www.tindie.com/products/15214/

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