Bit of a strange one ,but we have a Bluerov with the Topside power unit fitted ,vehicle appears to work fine until we switch the lights on then we loose picture or it freezes ,as soon as the lights get switched off we get picture back .This is running through the power tether and decklead around 300m .If we power it up only on the decklead we have no issues only when the tether is connected .We don’t loose comms and thrusters run fine .Measuring the voltage on the Pi and Pixahawk and also the terminal strips of the main power we get no dip in voltage.We have 2 tethers and get the same fault on both ,we have run this set up with the tether lengths for a while now with no previous issues.Anybody suffered this issue before .Many Thanks Mig
Hi @rovmig, welcome!
From the description, I can remember two things I’ve seen before:
- Interference from a power device (like lights) to signal devices (like the camera or with the Raspberry Pi);
- Camera exposure controls getting crazy due to the change in luminosity;
Against interference, I’d check the voltage in the power source, and the cables/connections and their spatial separation, keeping any power cable far from the Raspberry Pi and its accessories like the camera. Also, it’s a common practice to have each positive-negative pair twisted.
About the exposure scenario, as far as I experimented, rapid changes in lighting conditions can make the camera’s automatic control loop unstable, which can result in:
- a crash in the camera, usually when the rapid light change is done repeatedly. This is reversible only via a power reboot;
- the automatic control loop increasing too much the shutter open time, meaning that the frames take forever, and FPS goes to zero. This should be reversible by resetting the camera controls.
In this case, a suggestion to possibly (not tested) avoid this would be to play with the “Auto Exposure” controls, maybe using it in “Manual” mode, if doable.
Thanks