Hi all,

I've been out of the game for a few months and just got round to installing 3.0.1. Testing it out today in the back yard it seemed to work fine until I switched to Alt-Hold. In Alt-Hold mode the just kept wanting to climb until I switched it back to stabilise.

I've attached logs from two of the flights where this has occurred. Below is a graph showing the behaviour (taken from 2013-08-10 00-16 1.log). For some reason the WPAlt keeps increasing while Alt-Hold is engaged, but I can't figure out why.


I am running an APM 2.5 enclosed in the 3DR case (complete with foam covering the baro). My sonar is mounted as far from the ESCs and BEC as I can put it, and has powerline filtering.

I have the APM mounted on squares of anti vibration foam at each corner. I believe the vibrations are within what is acceptable (IMU logging is turned on - see for yourself). Finally, not that I think it affects Alt-Hold, I get around 40% interference when running the compassmot test.

If someone could take a look and let me know what's going on here it would be much appreciated.



2013-08-10 00-16 1.log

2013-08-10 00-43 2.log

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  • have you set THR_MID? if your THR_IN is graphed with the axis on the right, then it looks to be higher than the default 500. That would cause the copter to climb in alt hold

  • Tried without the sonar?

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