FFT analysing in log does not look like the FFT in wiki


This is my log: https://drive.google.com/file/d/1-ywN02faqGy-eojEAYSV9jMKr8v5WIwB/view?usp=sharing
I am trying plot some information (following this wiki https://ardupilot.org/copter/docs/common-imu-fft.html) FTN1.BwAvg, FTN2[N].PkX, FTN2[N].PkY, FTN2[N].PkZ… but they are nothing but the flat line like this, except the FTN1.PkAvg

Could anyone please have a look and let me know if I did something wrong?

That’s really strange. Looks like you have done everything right. Maybe a logging issue? Check your bitmask and card speed. I also note a couple parameters listed twice which also seems really strange.

This is my LOG_ anf FFT_ parameters:


pardon me, what do you mean by “card speed”, It is new to me.

How fast your sdcard is

My test tool said around 8Mb/s - 10Mb/s (Read by cheap PC SD card reader). This is the original SD card coming with Cube Orange.

Hello Vu Nguyen

Did you find the source of the issue?..I have the same result, right now.


Hi, I have not checked it from that time, will do it in the next tests.

@sofamio I have checked today and it still remains there. I am not sure someone could have some time to give it a check?