Alt Hold Just can't get it!

This flight is short. And I should have tested from higher up!

I have everything working except alt hold. I can't find a combination of gains that work. It always oscilates.

This time, I put it in loiter, it was stable for about 2 seconds, but when it tried to adjust for horizontal position the altitude started to drop, I think it made a small attempt to adjust, and then just dropped.

I cut to stab, but didn't have time to break the fall. It landed flat, but heavily.

Can anybody make sense of the log? I don't seem to have magnetic or vibrational interference.

I have noticeed that the GPS might not be as stable as it should be, I don't get a satellite count, I think my GPS only has the RMC message. I get a 3D fix and wait for about 3 minutes for the GPS to stablize.

2013-10-27 07-59-20.tlog

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  • Nothing, nobody? The actual flying starts at about 80% into the log.

    Is "alt_err" negative, that is, if the craft is too high, alt error is negative?

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