I have a atmega32u2 that came with a HID based driver that shows up at atmega32u2 and I use dfu-programmer to program it. I just bought a atmega32u4 and it came with a AVR CDC bootloader. I'd like to flash the HID bootlaoder on this one but I can not find the driver. My assumption is I can flash this chip via SPI if I had a hex file. Anyone know where to find it and what fuses I should set (has a 16MHz clock).
I see talk about this but nothing specific about the atmega32u2 or 4
this page explains it a bit https://helentronica.com/2015/07...
this page has a link to both bootloaders http://blog.lincomatic.com/?p=548
but its about a AT90USB1286 with no mention of other chips?
Also it is noted that "the ATmega32U4 comes with a USB DFU bootloader installed." Well great but what is someone over wrote it? Mine was shipped with another BL when I bought the project board.
So I need to buy a new chip?
Interestingly I did try reading the chip and wrote down the fuses but write this to the u4 (same fuses) didnt work. The boot loaderis not off but the new boot loader does not show up when jumping reset to ground. Still a bit fussy on this HWB pin but it looks to be shorted low when reset is held low (two pull button). I did notice the BOOTRST was not enabled on the fuse read but enabling it didn't help. I think I just need to get my fuses right.