To setup the project and upload the Arduino usbserial application firmware to an ATmega16U2 using the Arduino USB DFU bootloader: unpack the source into LUFA's Projects directory set ARDUINO_MODEL_PID ...

The LUFA version is 100807, as in the hardware-pinoccio repository. This version is required for both DFU and USB serial firmware. The arduino-usbdfu directory contains the DFU bootloader on the 16U2 ...

[Damian] used the lowly ATmega16u2 to generate the video timing. The 16u2 is normally used as the Arduino Uno’s USB interface. The only external hardware needed is a single 120 ohm resistor.