Arduino UNO and custom ATMEGA 8U2

Hello Arduino world,

One conceptual question of feasibility here : I want to be sure that I perfectly understand the very detailed article about reprogramming the 8U2 chip on the UNO board :

Does it mean that I can, without using anything else than my UNO board and USB cable :

  • Program the 8U2 with MocoLUFA firmware to have my Arduino board identified as a MIDI device

  • Program the 8U2 back to the Arduino loader

This as many times as I want !

Thanks for the clarification,


How many Unos do you have? You need an external device to reprogram the 8U2 chip. Another Uno could be such a device. You can't do what you describe with a single Uno and nothing else.

Thank you for the reply. Unfortunately I only have one UNO.

Does this mean that step 1 is feasible(bootloader->Midi), but in order to burn back the Arduino bootloader I shall use the 6 pin SPI programming tool?

I'd forgotten about the flip programmer thing. Possibly that will work both ways, I haven't tried it.

It is (as far as I know) a bootloader on the 8U2 chip, so it should be possible to keep reprogramming it.