FIFO timing Error

[dsouzahansen]

Posted on December 20, 2011 at 20:27

I am facing timing issue with lis3dh accelerometer in FIFO mode.Currently my ODR=25 Hz and I am reading FIFO on watermark threshold=30.As soon as I get watermark interrupt I read 196 (32*3*2)samples at 5 Mhz.Hence I clear the entire FIFO before the next ODR sample time=0.04seconds(1/25).

However after two minutes I am at an positive offset of one second.Is this due to inaccuracies in the accelerometer timing ?

Our application requires that all the FIFO data to be available at precisely 2 minutes.

Can you please tell us what can we do to achieve correct timed data.

#lis3dh #mems #support #lis3dh

[Fabio]

Posted on January 17, 2012 at 10:46

Please, for specific questions related to MEMS, use the ''ONLINE SUPPORT'' channel, available in  every product page.

LIS3DH:

http://www.st.com/internet/analog/product/250725.jsp

I am facing timing issue with lis3dh accelerometer in FIFO mode.Currently my ODR=25 Hz and I am reading FIFO on watermark threshold=30.As soon as I get watermark interrupt I read 196 (32*3*2)samples at 5 Mhz.Hence I clear the entire FIFO before the next ODR sample time=0.04seconds(1/25).

However after two minutes I am at an positive offset of one second.Is this due to inaccuracies in the accelerometer timing ?

Our application requires that all the FIFO data to be available at precisely 2 minutes.

Can you please tell us what can we do to achieve correct timed data.