The Arduino MIDI controller can be seen in action in the video below and full instructions have been published to the Imgur website which is accessible via the link below.

Nootropic Design has modified the Arduino platform to offer not only TV-out, but also a built-in game controller, as well as support for external controllers (including Bluetooth-based Wiimotes).

In need of a MIDI controller, Reddit user [Earthwin] built an Arduino powered one to control his Boss DD500 Looper pedal and the result is great looking.

New Arduino Esplora Provides A Ready-For-Gaming, Customizable, Open Source Video Game Controller Darrell Etherington 5:59 AM PST · December 10, 2012 ...

[Shantea] needed a DJ controller. While there are commercial controllers out there, none of them fit what he was looking for. He solved the problem by building the Tannin DIY MIDI controller. Tanni… ...

After purchasing the Qu4tro electric skateboard and finding the controller wasn’t quite as good as the skateboard, Timo Brinschein decided to build his very own using a little Arduino hardware ...

Electronics maker Adafruit Industries has developed its own Arduino-compatible boards, including one called the Flora--and a few craft projects to go with them.

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.

Modder TommyB has created a DIY Steam Controller 2 that splits into two, created using parts from the handheld gaming PC and a 3D printer.