LIS3DSH vector filter

[Manish Shrestha]

Posted on October 12, 2017 at 08:44

Hi, 

I wanted to used internal filter of the accelerometer LIS3DSH, but I couldn't find proper documentation regarding this. Can anyone please help me regarding this. 

[Babip Bipbop]

Posted on October 12, 2017 at 11:38

Hey,

could you give us more details about that? 

In what respect does this application note does not bring enough info ? 

http://www.st.com/resource/en/application_note/cd00290365.pdf

 

Cheers !

[Miroslav BATEK]

Posted on October 13, 2017 at 11:03

The application note is for LIS3DH which is different device.

[Manish Shrestha]

Posted on October 15, 2017 at 08:49

Hi, as Miroslav said the application note is of different IC. The LIS3DSH has internal 7 order FIR filter, I need to implement that filter. I need help regarding this. Any help will be appreciated. 

[Miroslav BATEK]

Posted on October 16, 2017 at 15:32

The application note for LIS3DSH is

http://www.st.com/content/ccc/resource/technical/document/application_note/a6/78/86/f9/88/c0/49/9b/DM00026768.pdf/files/DM00026768.pdf/jcr:content/translations/en.DM00026768.pdf

.

In the application note describes the FIR filter, but I'm afraid it is not useful as you would expect. The FIR filter is used only on a vector value calculated from X,YZ and the output value is used in the state machine and is not available externally.

[Manish Shrestha]

Posted on October 17, 2017 at 06:51

Batek.Miroslav

Thank you for your reply. I have look into the application note. There are couple of things I didn't understand. The filter use 8 input data, so should we mark FIFO to hold upto 8 data? Ordoes it automatically filter the data when we enable it regardless of FIFO? Also in the datasheet, there is a filter coefficient and claims it perform band-pass operation, but, it doesn't say about the cut-off frequencies or sampling rate to get that coefficient. Can you please help me regarding this?