High Clipping with Fast Sample On

I had a thread about switching from an omnibus w/ MPU6000 to Kakute Mini with ICM20689. Vibes were MUCH higher w/ the kakute. I learned this IMU is a lot more sensitive to the vibrations in my copter, and have fixed the issues. That copter is working well now.

Now even with relatively low vibes, I still get tens of thousands of clips with fast sampling on. With fast sample off, the vibes look about the same, but no clipping.

Here’s a graph:

Andy was helping me figure out the problems and did a little test w/ his Kakute Mini, and just blipping the throttle a few times caused thousands of clips on his.:

I wanted to mention this outside of my long kakute thread, just in case it is an issue.
Are other people seeing clipping w/ this IMU?

Is it safe to ignore all those clips?

@wicked1 my suspicon is that this is because in fast sampled mode the accels are unfiltered (whereas they are filtered for the gyros on this chip). I’ll do you a patch that allows you to filter the accels and alos to switch on “low-noise” mode which may also help.

Everything seems completely fine in flight…
Do you think it’s safe to ignore the clipping? Or better to just use fast sampling off? I don’t notice any performance difference, whether it’s enabled or not.

What flight mode? You only care for EKF flight modes …

Hmm, ok.
I usually use stabilize, but would like to know EKF modes are working reliably… Might need RTL one day, etc… I’m not getting EKF errors or anything now. I’ll try flying in loiter and fly a few missions to see what happens.

Stabilize won’t use the accels at all - so you are good. You might hit issues on RTL, but you might hit those anyway - all my small copters confuse the EKF if I have been burning around for a while - it could be accels, the GPS at an angle or a whole bunch of other things.

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Well, no apparent problems with loiter or auto missions even with the clipping. I’ll leave it like this for now.

Andy, thanks a lot for your help. When I’ve made these posts I always intend for them to simply be sharing information that could be helpful to you guys doing the coding, or other people using similar copters. I don’t intend for you to be my personal helpdesk, although that seems to be what happens…I was thinking last night that Ardupilot is the best example of open source collaboration I can think of, and a large part of that has been because of you. Everyone else, too, but you happen to be working on the things that help the copters I’m using. Thanks for all the work you’ve been doing.