LSM9DS1 Accelerometer Calibration required?

[djacobs]

Posted on May 01, 2017 at 18:41

We are making roll measurements (atan2(ay,az)) using the LSM9DS1's accelerometer.   We see extremely little error, just fractions of a degree.  Since this is within our required accuracy, we are thinking that we don't need to do any calibration to get our roll measurement.  Is this true?  We are confused by the datasheet which seems to suggest that errors as high as 90 mg are possible.  If a 90 mg error occurred in the Y axis, this alone would generate a 5 degree error in our roll measurement, yet we are seeing almost no error.  Is this calibrated in the factory?  Should we do our own calibration to ensure that we have errors less than 1 degree?  Thanks!

[Miroslav BATEK]

Posted on May 03, 2017 at 12:39

Yes, for accurate tilt measurement you have to to you own calibration for each device.

The mentioned 90mg zero-g level offset in datasheet is typical value, so it can be even worse.

[vladik pri]

Posted on August 17, 2017 at 13:31

How do you suggest to calibrate the accelerometer?

[Miroslav BATEK]

Posted on August 18, 2017 at 16:34

You can use MotionAC library which provides real-time accelerometer calibration. The library is available in

http://www.st.com/content/st_com/en/products/embedded-software/mcus-embedded-software/stm32-embedded-software/stm32cube-expansion-software/x-cube-mems1.html

software package.

Or you can perform 6-point calibration according to for example design tip

http://www.st.com/content/ccc/resource/technical/document/design_tip/group0/28/fa/7d/ed/6a/41/4f/c1/DM00253745/files/DM00253745.pdf/jcr:content/translations/en.DM00253745.pdf

.