LSM6DSL gyroscope high-pass filter reset

[flaufer]

Hi all,

I have a question regarding the LSM6DSL's gyroscope high-pass filter configuration.

For LSM6DS3, there is an option to reset the high-pass with HP_G_RST = 1. This way, the DC component of the angular velocity is immediately removed, c.f. https://community.st.com/ysqtg83639/attachments/ysqtg83639/mems-sensors-forum/21052/2/AN4650.PDF, figure 5, page 26.

How can I achieve the same with the LSM6DSL? According to the datasheet and application notes (https://www.st.com/resource/en/application_note/an5040-lsm6dsl-alwayson-3d-accelerometer-and-3d-gyroscope-stmicroelectronics.pdf) there is no such option here. I just tried setting the same bit of CTRL7_G to 1 but without the desired effect. Unfortunately, I can't wait for the filter to fully settle down for several seconds to minutes at its lowest cutoff frequency. Are there any workarounds?

Kind regards

Felix

[Federica Bossi]

Hi @flaufer ,

Welcome to ST Community!

Unfortunately, that functionality is not still available on devices newer than LSM6DS3.

What you could try is to implement an algorithm to subtract the DC component from the gyroscope output.

[flaufer]

Hi @Federica Bossi ,

thanks for clarification.

Yes, I could basically implement the high-pass myself in software. I wanted to avoid that since it would be most certainly less effective than on the device (at least for small cutoff frequencies << 1 Hz at 208Hz sampling). But probably I will do that just for the very initial phase until the LSM6DSL's HP has settled.

Do you maybe have some more information about the LSM6DSL's HP such as the filter type and order?