I’m suddenly having a problem with my APM board giving “Bad Velocity” warning on the prearm checks. I’m also seeing in mission planner that the virtual horizon is steady and level most of the time, but about every 4-5 seconds it jumps by 30degrees before settling back.
I understand bad velocity warnings to be related to accelerometers, so I re calibrated them (first 3 attempts failed - probably because I was doing it by eye in my - not altogether level - flying field 4th was successful).
This seems to have made no difference.
I’m running V3.2.1 of the firmware on a 2.6board with external GPS/compass, on a flamewheel 450, Futaba r3008sb, 3s lipos.
A week ago it was arming with no problems flying normally, and I’ve never crashed it or dropped it etc. No changes have been made to set-up other than I was playing with adding sonar (since removed and all related params reset) and I increased WPNAV_LOIT_Speed from 500 to 1000.
Any ideas how I can diagnose/test the issue?
I am aware that I can diasable the pre-arm checks, but I’m not sure how dangerous this might be given the glitching horizon (which I guess is related)
Unfortunately I have no logs (as it won’t get off the ground!)
Unfortunately I havent got any logs… they are set up to log everything, but as im not getting off the ground im not seeing any logs created…is there a way I can force it to create a log without getting to 20% throttle?
It might be a bit of a long shot but you could check the health of your 3.3 volt voltage regulator, since you are using an APM. You could have blown it messing with the sonar. Have a look at the link below and see if the video sounds anything like your problem:
I also get the same error message of bad velocity prearm from time to time on my APM2.6. I checked the voltage regulator and found the voltage is normal at 3.28 V. But the message went away shortly and I can thus arm.