LSM6DS3 gyro data is off by about 15% of what I expect

wild · ‎2016-02-25

Posted on February 25, 2016 at 19:26

Greetings.

I am trying to get accurate gyro data out of the LSM6DS3, but my results are about 15% off of what I expect.

My test setup is a PASCO scientific Rotary Motion Sensor (RMS) with a LSM6DS3 mounted on top of it.

I configured the LSM6DS3 such that full scale +/-32767 is mapped to +/- 1000 dps.

I then rotated the RMS and LSM6DS3 at 366 dps (as measured from the RMS) and the LSM6DS3 gyro reported a z-axis rotational value of 10173.

My calculated gyro z-axis rotational velocity for this value is

10173 counts * (1000 dps / 32767 counts) = 310 dps.

Why is the gyro reporting 310 dps when it is being rotated at 366 dps?

What is the guaranteed accuracy of the gyro?

Thank you

Scott Wild

oyvind2 · ‎2016-03-17

Posted on March 17, 2016 at 15:19

Hi Scott,

The actual value of one ADC count at your setting is 35 mdps, according to the datasheet. If you use this value, you will get a much closer result. I suppose they call the full scale +-1000dps just to give it a round number. The actual full scale would be 0.035*32768 = 1147 dps.