At the start(when first powered up), BNO055 sensor reads the angle in a wrong way, then the it is calibrated by rotating, afterwards the problem is gone and angle reading becomes correct in the normal condition(no relatively magnetic distortion).
The problem is that when the BNO055 starts(when first powered up) near the something having the electromagnetic field(on the vehicle), it shows initial position as 0 degree, but in the normal condition, it shows the correct angle at the beginning.
Could wen know some information for your application:
Did you use NDOF mode with BNO055?
Could we know what your product application is?
Where did you place BNO055 on the vehicle?
To make the our process clear, let me tell you the our process from overall perspective.
Our job is to put satellite antenna on the vehicle and point the satellites from our antennas.Therefore, we need to know which angle we are in exactly before the pointing process. For this reason, we are using Gps&Compass modules having BNO055 and these modules are fixed to the vehicles(it is not relocated after the calibration and is located on the top of the vehicles).
For testing, we just bring something, that has magnetic field, closer and calibrate it, after that , power off the module.
After re-powering, BNO055 accepts the starting position as 0 degree no matter which position it is located.
I want to see the correct angles after re-powering the sensor because after first calibration, the vehicle is parked and could not enter the calibration process again and again.
My expectation is to preserve the calibrated angle values after the re-powering , because after the calibration, there is no magnetic field chance (same with before the calibration) .
Thanks for your feedback.
What is the change of calibration state when you put something with magnetic field close to BNO055?
It seems that the intensity of the magnetic field is high, and the calibration state value will become smaller.
No it is just normal vehicle , it is not that something has high magnetic field intensity,
It is quite easy to try in your side.
You can try with putting magnet close to the sensor, after re-powering, that sensor accepts the starting position as 0 degree no matter which position it is located.