3.1 GPS problems, when activated just flies away


upgrade to 3.1 and autotune worked great! I just manually lowered the Stabilze P values to fly “smoother” and recently also the Rate P values due to strong decent wobble. Awesome now.

BUT: I have a problem since upgrade to 3.1 / (after autotuning?) with my GPS:

First I got GPS error messages not being able to arm- that just happened once- but this is gone now.
Flies great BUT

I am not able to LOITER (did not try other GPS modes)- copter just flies away in some (random) direction.
Calibration of compass is perfect- vibration levels really low, Alt hold also great. (at least from my understanding)

I already tried changing the PID settings for loiter- no difference (more aggressive fly away behavior but still no holding position AT ALL) I looked at the logs- no idea- just low sat count (8) and hdop could be better.

PLEASE, please have a look at my logs (have more but too big to upload here) because I am stuck and one big reason for arducopter is GPS…
I am not planning to rely on it but would feel MUCH better to have it working on that expensive quad “just in case…”

I have no idea what might cause the issue, so any help would really be appreciated!



I think they have GEO Fence enabled, please disable.
then the error could be corrected.

Looks to me like it knows its flying away, as the WP distance is increasing. My guess would be that its compass related - I see you’re using throttle-based compassmot. Try re-doing the compassmot setup to see if that helps at all.


thinking about it helped- also did Rickp s reply: when the APM knows it flies away it has to be compass related?
Aaaaand- it accelerated doing so…

Why- easy- it “thought” if flies towards the correct point, error increased, it accelerated…
The external compass I used was EXACTLY 180 deg Yaw off- this explains why just going straight and increasing banking with distance!

So did I the correct 180 deg Yaw setting and now it works sooooo nice! We have a little wind today but still it held position within a meter or so!!

Will test the GeoFence feature soon but expect it to work as good as the rest does!

If the glitch protection also works I guess this is a huge safety improvement for those long range FPV flight nobody does :wink:

Kind regards and thanks a lot!