I have been trying to flash firmware (following the instructions on https://www.ardusub.com/developers/developers.html) for a few hours now. I started out on Ubuntu on a VirtualBox machine. It was not working so I tried it on windows using WSL. I can compile no problem, but once I try to upload it to the PixHawk It just get stuck at
Loaded firmware for 9,0, size: 1044400 bytes, waiting for the bootloader…
If the board does not respond within 1-2 seconds, unplug and re-plug the USB connector.
I have tried unplugging and plugging back in, no change. I have tried multiple USB cables, no change. I can flash stock firmware just fine using QGC. I tried flashing a binary of the firmware using QGC, but that just made is so the pixhawk would no longer talk to QGC. I have not changed the firmware I cloned from github, so it should be the same as the QGC firmware (although that is V 3.5.4 and the online instructions tell you to use tag 3.6).
Any help would be greatly appreciated as I need to be able to flash custom firmware in order to use a custom frame.