Turn an old mixer into a MIDI input fader with Arduino

Using an Arduino as an HID, Evan Kale turned a “gently used” analog mixer into a computer interface.
Older audio equipment may not have the interfaces that you need to make totally electronic music, but they can be very well-built, so are perhaps worth salvaging. In the video below, Kale salvages potentiometers from an old mixer, then hooks them up to a Pro Micro. This allows the Arduino to take these 12 inputs, and output them as a USB MIDI signal.
Along the way, Kale points out a few very important hacking tricks, including that the library may have a printer ready for you to use, and that analog slider pots many times are logarithmic (or close to it) and need to be calibrated. Also, around 5:25 he introduces viewers to analog multiplexers which can give you eight analog inputs at the cost of three digital and one analog pin.
You can check out more of Kale’s Arduino-based hacks on his YouTube channel here!





fair amount of patience so you can solder all the 36 LEDs, switches, transistors, and resistors but in the end, you’ll end up with a brand new computer to play with. In 1975, an assembled Altair 8800 Computer was selling for $621 and $439 for an unassembled version. Sourced right, your clone would be under 50 bucks. Not bad.