IMU Mismatch = WARN Large spikes in log graph

I’ve had some problems with an IMU Mismatch = WARN. My vibrations are low and the Hexa flys well in all modes. What I have found are large “spikes” in the ATT yaw graph, in AHR2 yaw and GPS GCrs. But it’s nothing I can see, feel or hear when the copter is in flight.
Different mission log

And I’m wondering if is related to my other problem linked here;
Stopping between WPs

Thanks for your help

Despite the crazy spikes in yaw, there is no weird behavior from the aircraft.

Any ideas?


I have encountered this in the past as a data corruption in downloading the log files.

Have you looked at the log entries in the spreadsheet of these spikes to see the values?

You have not said how you get your log files.
Mine happened with a dodgy USB cable and an earlier version of VMware Fusion to run Mission Planner on a Mac.

Hey Mike thanks for the reply. So I just tried a different usb cable and down loaded the log to different computer and no change, same spikes. Thanks for the thought. I’m downloading the log threw Mavlink and an usb cable

Hi Paul,

Those spikes are very close to 360°, which means that your heading is close to 0° and there’s some expected noise which makes it goes to 360° from time to time. As you know, in heading, 0° is the same as 360°.

If your hexa is flying without problems, I wouldn’t worry about it.



Ah! Of course that’s what it is, thanks Javier.
I couldn’t see the forest through the trees!