I have an OpenMV H7 Plus purchased in Jan 2023 which all worked fine. Coming back to it after a couple of years, now on Win11 and OpenMV IDE 4.7.0, it works fine but asks me to upgrade the firmware. Following the instructions, it fails at the point where it should enumerate the DFU Bootloader. Tried re-installing the IDE, on win10 and win11, and different leads but to no avail. Device manager shows nothing detected after connecting BOOT and RST pins.
I have fixed the issue: Connecting RST and BOOT doesn’t bring the BOOT 0 pin up the 3.3v. So connecting BOOT 0 to a 3.3v source put the device into DFU mode and the upgrade proceeded correctly. The RST pin appears to be floating on my module - maybe someone with more knowledge can explain exactly what is going on!
The instructions for DFU mode are “link the Reset and Boot0 pins” (presumably) to bring BOOT0 high at power up. On my board Reset is high 3.3v and BOOT0 low 0v. When connected they are at 0.6v so not high for DFU mode.
I simply connected BOOT0 to the 3.3v pin via a small resister (1K - maybe unnecessary) and it went into DFU mode.