Alt changing with yaw

ArduCopter Copter 3.4
1

Still 3dr Y6B with Pix Lite, but with new vibration dampening mount.
With 3.4 rc4 new problem: Altitude changes when turning copter. In the log the GPS-Alt seems to be wrong while Baro shows right measurement.
Also tried oneshot 125 - works fine, but it takes more than a minute until all ESCs are armed.

Thanks
Hubertus

2

Update:

Disabled safety switch -> all ESCs arm immidiately. Anyway - this is no permanent solution.

AltHold Problem is gone, perhaps was related to bad compass calibration.

Works great now, will try follow me later.

Thanks
Hubertus

3

Humbertus,

When safety switch was enabled, did your motors twitch after unlocking the switch with oneshot125 ? Are you running mot_pwm_type=2?

Thanks,

4

For anyone using follow-me, of course just make sure you’ve got the latest Tower Beta. You may have seen from previous discussions that Tower was previously sending absolute-altitude requests - we just never noticed until Copter-3.4 came out which includes support for absolute alts and alt-above-terrain.

Re OneShot, yes, Luis and Tridge were discussing something similar this morning.

5

Fernando
yes, the motors twitched while giving the ESC arm signal. But it took about 2 min until the last one armed. Yes, I use mot_pwm_type 2.

Hubertus