When I first power up my control board & connect to Mission Planner, the altitude reading is extremely high - often up around 500 to 600 meters, though the model is sitting right here on my desk. Within about a minute the altitude reading adjusts down to somewhere between 0 and 1 meter.
Is this normal behavior or something wrong with my barometer?
I have also noticed that if I don't give the barometer enough time to settle when powered up for flight, the motors will run as soon as I arm the control board, even with the throttle at zero. This has caused a bit of freaking out on my part thinking the 'copter is about to go it's own way, but it never takes off. I have been able to get under it to unplug the battery when this happens. I never have waited long enough to see if the motors would quit after the barometer becomes acclimated, but I now think they are running because the board thinks it is falling from a high altitude. I could be totally wrong... If I give it a minute after powering up it never does this.