Ultimaker 2 mainboard USB damaged

[conny_g 251]

Hi there,

a while ago I did some hacking & measuring with the Ultimaker 2 mainboard and likely due to some sort of USB ground loop between laptop / oscilloscope, and the laptop USB connection to the Ultimaker I destroyed the USB port of the UM mainboard (v2.1.4).

At least since then the USB connection to the board does not work any more.

Back then I have replaced the board with a new one and the printer works. But I would like to salvage the old board and repair it, if possible.

I researched the board schema and obviously the USB connection is built with a Atmega16U2.

My assumption would be that the Atmega or it's USB pins are damaged and I would like to exchange the Atmega and reflash it with the firmware. (There is a fuse before the Atmega, but it seems to be ok, unfortunately - it would be easier to change the fuse.)

Where can I find the firmware of this Atmega16U2?

I know where to find the Marlin firmware (customized that already), but could not find the USB firmware yet?

Regards,

Conny

[conny_g 251]

Found the answer:

As the Ultimaker 2 main board bases on the Arduino Mega2560 this part is simply identical.

The schematics here are almost the same:

https://www.arduino.cc/en/uploads/Main/arduino-mega2560_R3-sch.pdf

https://github.com/Ultimaker/Ultimaker2/blob/master/1091_Main_board_v2.1.1_(x1)/Main%20Board%20V2.1.1.pdf

And for that the firmware is simply the Arduino one for the Atmega16u2 that builds the USB to serial bridge on the Atmega2560:

https://www.arduino.cc/en/Hacking/DFUProgramming8U2