Here's my situation: I attempted to make a custom card in order to serve as a USB host and perform various other I/O functions. I found out after I had the cards produced that I did not choose the correct microcontroller for being a USB host, but I would still like to salvage these boards, if possible, for some other (non-USB) functionality, e.g. using the 8u2's ports as inputs / outputs.
My initial thought was to maybe treat 8u2 as an ATmega8. I found a bootloader for the ATmega8, burned that into flash, and then tried to download code via the normal FTDI / TX/RX route, setting the COM port to a baud rate of 19200 (which should match the bootloader). That did not work.
From what I've read, I now realize that the ATmega8u2 is very different from what I'm used to (e.g. ATmega328) in terms of bootloaders, how you download code, etc.
My question is this: Is there any way to salvage this hardware and get my boards functioning?
Thank you, Bryan