I have the IIS3DWB configured in single Axis mode and I keep seeing a clear peak in the spectrum at 9.5kHz even when the sensor is stationary. I'm not sure why this is happening given that i have also configured LP2 to ODR/4.

DOlud.1 · ‎2021-10-13

Please see attached a screenshot of the spectrum and a snippet of my code. thanks

Eleon BORLINI · ‎2021-10-14

Hi @DOlud.1 ,

I'm not sure to be able to see well that peak, but it looks like a "Dirac delta" on a linear scale, so my guess it that is not due to a mechanical issue.

For sure, this is not the IIS3DWB MEMS, since its 3db cutoff frequency is around 7kHz. I'm pretty sure also that it is not the ASIC, since there are no electrical reasons for this behavior.

Might it be the main SPI / I2C communication frequency you are using in your application processor? Did you test the code on other parts?

And are you seeing this peak configuring the device in 3-axis mode?

By the way, if you are not interested in it you can simply low-pass filter that peak, at leas in post processing.

-Eleon

View solution in original post

Eleon BORLINI · ‎2021-10-14

Hi @DOlud.1 ,

I'm not sure to be able to see well that peak, but it looks like a "Dirac delta" on a linear scale, so my guess it that is not due to a mechanical issue.

For sure, this is not the IIS3DWB MEMS, since its 3db cutoff frequency is around 7kHz. I'm pretty sure also that it is not the ASIC, since there are no electrical reasons for this behavior.

Might it be the main SPI / I2C communication frequency you are using in your application processor? Did you test the code on other parts?

And are you seeing this peak configuring the device in 3-axis mode?

By the way, if you are not interested in it you can simply low-pass filter that peak, at leas in post processing.

-Eleon

Eleon BORLINI · ‎2021-10-21

Hi @DOlud.1 ,

any feedback about your issue?

-Eleon