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sumic
·Posted in MEMS sensors forum

Questions about abnormal gyro self-calibration results on BMI323

Hello,

I have two BMI323 sensors. I used the official API example for gyro self-calibration from BMI3XY SensorAPI - self_calibration example to calibrate them.

Before calibration, I ensured that the gyroscope was placed horizontally and kept completely still. However, the calibration results seem unusual, and I am not sure where the problem is. I am wondering if this could be caused by chip damage due to soldering or if the results are actually normal.

I am using an ESP32-S3, reading data via I²C. I also ran the selftest example from the same API, and all tests passed, so the sensors appear to be working normally.

My main concerns are:

  1. The gain values seem significantly smaller than expected.

  2. The offset values frequently show numbers like 1023. Is this a valid reading, or does it indicate a fault?

Below are the multiple self-calibration results I obtained for each sensor:

Sensor 1

Self-calibration for sensitivity mode

Self calibration is successfully completed

  • Result of gyro dp offset x(LSB) is 0

  • Result of gyro dp offset y(LSB) is 0

  • Result of gyro dp offset z(LSB) is 0

  • Result of gyro dp gain x(LSB) is 124

  • Result of gyro dp gain y(LSB) is 124

  • Result of gyro dp gain z(LSB) is 7

Self-calibration for offset mode

Self calibration is successfully completed

  • Result of gyro dp offset x(LSB) is 0

  • Result of gyro dp offset y(LSB) is 4

  • Result of gyro dp offset z(LSB) is 1021

  • Result of gyro dp gain x(LSB) is 0

  • Result of gyro dp gain y(LSB) is 0

  • Result of gyro dp gain z(LSB) is 0

Self-calibration for sensitivity and offset mode

Self calibration is successfully completed

  • Result of gyro dp offset x(LSB) is 0

  • Result of gyro dp offset y(LSB) is 4

  • Result of gyro dp offset z(LSB) is 1021

  • Result of gyro dp gain x(LSB) is 123

  • Result of gyro dp gain y(LSB) is 124

  • Result of gyro dp gain z(LSB) is 7

Sensor 2

Self-calibration for sensitivity mode

Self calibration is successfully completed

  • Result of gyro dp offset x(LSB) is 0

  • Result of gyro dp offset y(LSB) is 0

  • Result of gyro dp offset z(LSB) is 0

  • Result of gyro dp gain x(LSB) is 122

  • Result of gyro dp gain y(LSB) is 2

  • Result of gyro dp gain z(LSB) is 6

Self-calibration for offset mode

Self calibration is successfully completed

  • Result of gyro dp offset x(LSB) is 0

  • Result of gyro dp offset y(LSB) is 0

  • Result of gyro dp offset z(LSB) is 1023

  • Result of gyro dp gain x(LSB) is 122

  • Result of gyro dp gain y(LSB) is 2

  • Result of gyro dp gain z(LSB) is 6

Could you please let me know if these calibration results are within the normal range, or if they may indicate hardware damage?

Thank you in advance for your help.

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