notes and implementations of some midi interfaces
- main processor on Arduino Uno, ATmega328P, can't speak USB.
- so, a second processor, ATmega16U2, (the square IC between the USB port and Tx/Rx LEDS) is programmed as a USB-Serial translator.
- by default, the ATmega16U2 is flashed with firmware to allow you to load your Arduino Sketches from your laptop.
- since we want out Arduino to be recognized as a USB-MIDI device, we need to re-flash it with new firmware (see below).
dfu-programmer- commandline tool to flash firmware onto a variety of chips (brew install dfu-programmeron OSX)hiduino- contains the new firmware to change our arduino into a USB-MIDI device (git clone git@github.com:ddiakopoulos/hiduino.git)MIDIUSB- Arduino library for MIDI (download via Arduino package manager)
- make sure the arduino is in DFU mode if you need to flash see this pic
- make sure default arduino usbserial firmware is flashed on ATmega16U2
- write sketch
- load sketch onto Arduino
- flash ATmega16U2 with
hiduinofirmware - unplug/replug
- test and repeat
this process is automated in the included cli tool
arduinoctl
- the
hiduinorepo contains the new midi firmwarehiduino/compiled_firmwares/arduino_midi.hex - to reflash the default arduino firmware, clone the Arduino AVR Cores repo and use
/ArduinoCore-avr/firmwares/atmegaxxu2/arduino-usbserial/Arduino-usbserial-uno.hex - since the new midi firmware can't support loading sketches, we need to reflash the default arduino firmware each time we want to load a new sketch.
- remember to always unplug/replug in after flashing
- if you get
dfu-programmer: no device present.you need to set the arduino to DFU mode.