H3LIS331 Thresholds

[John Cooper]

Posted on February 21, 2017 at 18:07

Hello,

I am having an issue with the H3LIS331 thresholds. I have all the thresholds setup in high interrupt mode for all axis. The high pass filter is enabled, my range is 400Gs, my sample rate is 100Hz and my communication spi clock is 1Mhz. Sometime when I read a the acceleration values after an interrupt I get value less than my threshold. 

Sometime these values are even all below 1G. I have measured with a O-scope that I am reading the results faster than my sample period, 130uS. It seems like the threshold itself is working because I only get an interrupt when an event occurs but values seem wrong.

Is there some other register setting that I need to do?

Is it possible that the value of the acceleration registers change in less than a sample period from the interrupt? 

We are close to production and this issue has people worried.

Thanks,

John

#h3lis331

[Oliver Beirne]

Posted on February 23, 2017 at 09:19

Hi John

I have moved your question to the

https://community.st.com/community/mems-sensors-community/mems-sensors-forum?sr=search&searchId=5ffa5ade-7a7f-41f7-ac69-3e3de5827a61&searchIndex=1

‌ where someone should be able to help you.

Thanks!

Oli

[Martijn Jonkers]

Posted on March 12, 2018 at 15:24

I Am observing the same thing. I am pretty sure we read the data before the next sample is ready.

Managed to get an answer to this?

[Miroslav BATEK]

Posted on March 19, 2018 at 15:01

Can you share with me the threshold settings and the values which you read at the time the interrupt is triggered?

[Martijn Jonkers]

Posted on March 19, 2018 at 15:05

see

https://community.st.com/0D50X00009XkeVRSAZ