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Graduate
May 30, 2022
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LSM6DSR Gyro sensor angular rate sensitvity and calculation?

  • May 30, 2022
  • 2 replies
  • 2909 views

Dear all,

  1. How to get the Angular rate sensitvity from Full-Scale range of LSM6DSR? what is the formula to get 4.375 mdps/LSB from FS = +/- 125?
    1. My understanding is signed 16-bit max positive value = 32767, FS = +125 dps, then one dps / LSB = 125 / 32767 = 3.8 mdps / LSB, why the datasheet is 4.375 mdps/LSB?
  2. If we get the raw data from register, the actual angular velocity is raw_data x angular rate sensitvity? AngularRate[0] = (int32_t)((float)((float)data_raw.i16bit[0] * sensitivity));

Thanks.

  1. 0693W00000NqqBqQAJ.png
    This topic has been closed for replies.
    Best answer by Eleon BORLINI

    Hi @E-John​ ,

    your calculation is in theory correct, but consider that for avoiding nonlinearities at the edge of the sensor full scale, the actual sensitivity is greater than the "digitally calculated" sensitivity. It also takes into account gain coefficients that are calibrated at production level.

    Please consider the datasheet value as the correct one for the LSB to physical units conversion.

    -Eleon

    2 replies

    ST Employee
    June 3, 2022

    Hi @E-John​ ,

    your calculation is in theory correct, but consider that for avoiding nonlinearities at the edge of the sensor full scale, the actual sensitivity is greater than the "digitally calculated" sensitivity. It also takes into account gain coefficients that are calibrated at production level.

    Please consider the datasheet value as the correct one for the LSB to physical units conversion.

    -Eleon

    E-JohnAuthor
    Graduate
    June 3, 2022

    Hi Eleon,

    Understood. Thanks for your explanations.

    E-John