I reprogrammed the Atmega32u4 on my Arduino Uno Wifi Rev2 in order to use it as a human interface device, but I am now having difficulty programming the 4809 (through the 32u4 over UPDI) with the Arduino software. I have tried reprogramming the 32u4 with medbg_updi.hex from Atmel Studio and also Xplained Yourself Firmware from https://hackaday.io/project/162372-xplained-yourself.
I have had some success writing some smaller applications to the 4809 but when I try to program larger applications (which used to work before I fiddled with the 32u4), I now get verification error saying that there is a mismatch.
avrdude: verifying ... avrdude: verification error, first mismatch at byte 0x0200 0x08 != 0x0c avrdude: verification error; content mismatch avrdude: jtag3_edbg_signoff(): unexpected response 0x03, 0x80
When cross referencing with other working Uno Wifi Rev2 boards, they have
ICE firmware version: 1.19 (rel. 57)
while I now apparently have
ICE firmware version: 1.13 (rel. 43)
I do not see any place to find the updated/original firmware which came with my arduino. My thought is that the firmware is not available for direct download because it may be licensed from Microchip (Atmel) and not distributed/proprietary...
Please assist me if possible in restoring the full functionality of my Arduino Uno Wifi Rev2. Any insights would be appreciated.