Hi chaitanyai,
1. Did you use the example code https://github.com/BoschSensortec/BoschSensorHub/blob/master/examples/orientation/orientation.ino and load firmware "Bosch_PCB_7183_di03_BMI160_BMM150-7183_di03.2.1.11696_170103" for your hardware?
2.Accuracy means the calibration status of funsion algorithm, value 3 indicates that the calibration is complete and the algorithm outputs the best data performance. Value 0 indicates that sensor was uncalibrated. Because you have used a geomagnetic sensor, you need to consider whether the surrounding magnetic field environment has changed, causing the calibration state to drop, and you need to recalibrate.
3.What is your sensor placement and target coordinate system like? You could draw a picture to show it.
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