I’m working on a project that would greatly benefit from being able to load .hex files off of an SD card, and then flash the ATMega chip to essentially run different programs at will.
I’ve browsed the forums for doing this, and the general concensus is that I would need to write a bootloader that reads an SD card to flash. While the Uzebox does this, I’d rather not get into that - way more than I want.
Instead, I was thinking of using two ATMegas - one which is the standard Arduino running the standard bootloader. The other loads .hex files from an SD card and uploads them to the first chip.
Is this feasible? If so, can someone point me to the protocol for serial program uploading? (I essentially want to emulate the Arduino UI upload). I read the app note on the original STK500 protocol, but it wasn’t exactly very clear, and going through the source code for the bootloader is rather confusing as well.