Hi mmurty, I think it would be important here to specify exactly which bit you are monitoring, as each calibrator is different. The purpose of the calibration save & reload feature is to enable either a faster calibrated state, or enable calibration for devices that we would never make the correct movement in-use (e.g. anything mounted on a vehicle isn't expected to rollover during normal use). So can you please recommend some workaround to avoid frequent recalibration? Unfortunately, BNO055 calibrators are always-on by design, so the calibration will always run in the background, and if it finds better calibration values, it will keep updating the registers. what we notice is, several times when the sensor wakes up from Suspend --> Normal mode, the calibration status bits indicate loss of calibration. Could be several causes for this. For magnetometer, if the environment changed while powered off (e.g. moving from outdoor to indoor, or moving several kilometers, staying off for an extended period of time) then the calibration is no longer valid. The magnetic field really isn't a constant at all. You can take a look at a free magnetic field calculator: https://www.ngdc.noaa.gov/geomag/calculators/magcalc.shtml#igrfwmm This will give you the value of the expected magnetic field outdoor, without the shielding effect from metal around the device or building structure. For gyroscope calibration, very small changes in offset due to temperature or aging will be compensated out by the built-in calibrator, this will be reflected by the status indicator.
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