How to choose the right acquisition time in the FFT setting for ism330dhcx vibration sensor (6667Hz)

JTam.1 · ‎2021-08-11

Hi, in the ST BLE App, how to choose the right acquisition time in the FFT setting for ism330dhcx vibration sensor? Please advise. Thanks!

TBomb.1 · ‎2021-08-12

Hi, it depends on your application, but it seems that the ST BLE App is limited to 1024 samples, so you can configure the 6667Hz ODR but you have a limitation on the sample rate. SO maybe 3333Hz are enough to exploit all the FFT band.

Tom

JTam.1 · ‎2021-08-12

Hi, any guideline of choosing the right acquisition time in the FFT setting? Any supportive reasons? Thanks!

TBomb.1 · ‎2021-08-18

Hi @JTam.1 ,

you might refer to this white paper, that explains a bit how to choose FFT parameters in general.

https://www.st.com/content/ccc/resource/technical/document/white_paper/group0/c0/30/46/2f/00/24/42/1c/Capacitive_MEMS_accelerometer_for_condition_monitoring/files/MEMS_Condition_monitoring.pdf/jcr:content/translations/en.MEMS_Condition_monitoring.pdf

Tom