Recovering files from Arduino Mega 2560 via USB port


I am not sure if this is a programming or technical problem. So please move this thread if this is the wrong section. I am actually a bit to confused where to start looking for help since google research didn't give me anything that is even in the same ballpark as my problem.

Long story short: I am using an Arduino Mega 2560 to operate my 3D printer. I haven't touched my printer in about a year do to a new job and other stuff that keept me busy. In the meantime I had to reset my computer about three times, meaning that I have lost all previous files.

Since I have got a Frankenstein printer (custom silicon heatbead, custom thermisters, nozzle ... etc.) it would be a real pain to call every single company I have bought stuff from and gather all information again and adjust all the scripts to my needs.

So my question is: Is it somehow possible to recover the data I have loaded up to my Arduino Mega and kind of "download" the files from it?

Certainly, you can use avrdude to grab the executable code off your board.

Well, that was indeed a push in to the right direction, but I am afraid that there is not enough documentation for that program out there to help an untrained guy like me to even get that programm running. And yes, I mean it. I had to fight my way through the unsorted dowload section, just to see that programm not being willing to run.

What would you do with the hex file, if you were able to recover it? It will look nothing like C++ code.

I know this is no help at all - but how about going back to your 'backups' from 12 months ago... I deal with similar problems on a weekly basis. Unfortunately, there is no substitute for discipline.