If possible, please test out our new bootloader and let us know if you have any problems with it. You can do this by downloading the latest version of OpenMV IDE, and then using the Tools->Run Bootloader option to install the latest DFU firmware on your OpenMV Cam. You can grab the latest firmware here. For the OpenMV Cam M4 please select the OMV2/openmv.dfu file.
Once you’ve updated the firmware on your OpenMV Cam via DFU you should be able to use the regular bootloader in the IDE without issues to update your OpenMV Cam. To do this plug your OpenMV Cam into your computer, connect to it in the IDE, and then click on the firmware version label. The IDE will tell you your firmware is up to date, after which it will ask if you want to upgrade anyway. Say yes and the IDE will try to flash the latest firmware onto your OpenMV Cam.
Anyway, please let me know if you have any problems with this. In particular, the bootloader wasn’t able to connect to the IDE fast enough before because we had too small of a timeout. We’ve made the bootloader smarter now and it waits a lot longer for the IDE to connect if it detects that it’s connected to a computer. So far, in my own testing I can get it to work on Ubuntu VMs. So, I think everything is fixed.
(WARNING: If you need to use your OpenMV Cam for some task in the near future don’t do this right now. While I believe you shouldn’t have any issues… It would not be wise to invite problems for yourself if you can’t afford to have any).