The HIDUINO project provides firmwares, documentation, and example code for building a class-compliant USB-MIDI device from an Arduino UNO or Mega 2560. HIDUINO does not use middleware software to convert serial messages through a MIDI loopback port (like LoopBe1 on Windows or IAC on OSX). Instead, HIDUINO provides a true USB-MIDI device for plug-and-play compatibility on Windows, OSX, and Linux - just like a commercial MIDI controller.
These firmwares are directly based off of the LUFA framework by Dean Camera, a generic USB/HID library for Atmel’s line of ATmega USB-compatible microcontrollers. The project name refers to a time when it was intended to contain many different USB-HID device types (joystick, mouse, keyboard, etc). The name "mididuino" is in use by an existing project, though it would be a more fitting title for this project.
The project was presented at the New Interfaces for Musical Expression conference on May 31st, 2011 at the University of Oslo. To the side is a recording of the presentation. Notable mentions of HIDUINO include Hackaday, Arduino, and Adafruit.hiduino on github