Optical flow only works on boot from USB

Since I updated to AC3.5 (and 3.6dev), the optical flow module will only boot right if I power up via USB before connecting the battery. This is quite annoying, since th lidar lite I have connected will only boot right from the battery due to current draw. These complications have me in a dead lock, rebooting multiple times to get to the ‘sweet spot’ of plugging the done in just right.

I’m running the old drivers recommended in the wiki, and the FC is a HKPilot32.

Any ideas? Is there any logging I can turn on here?

I’ve responded to this somewhere else but in any case I’ve tested Optical Flow with AC3.5-rc5 and master and it seems to be functioning. At least it’s sending back the opt_m_x and opt_m_y values whether it’s powered by USB or battery.

I suspect this is a problem with how the optical flow sensor is being powered. Perhaps there are too many peripherals (radios, receiver, etc) being powered from the flight controller. I recommend powering the optical flow separately and/or checking the board voltage.

Another idea is to go back to AC3.4.6 (stable) to make sure the issue is new.