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.

The hall effect sensors are connected to I2C I/O expander ICs which connect to an Arduino Nano, one for each side of the instrument, which sends out MIDI messages via serial.

In this beautiful, well-documented, cat-assisted hack, [capricorn1] adds visual dimension to his impressive piano skills by using his keyboard’s MIDI output to drive Edison bulbs. He hung the… ...

Oh, and a USB to MIDI converter, and a DMX output connector, and a hub because there aren't enough free USB ports. So... yeah. It worked, though, and let me develop the software.

The OONTZ uses a 3D printed case, a 16 button keypad, an Arduino Leonardo, a monochrome driver, and a few potentiometers. It's actually a pretty simple thing to build yourself provided you can the ...

You are thinking: “yet another MIDI controller with Arduino”. Pedalino is something new from any previous DIY projects and even better of commercial alternatives at a fraction of the cost.

YouTuber Alex Coover, aka Glacial Geyser, has build an awesome Arduino-powered MIDI controller to help with his budding music career. Here's a demo.