BNO055 Inconsistent Quternions

[M08]

We run the the IMU in the NDOF-Mode. 

Several measurment cycles are done with the IMU placed at the same initial position on an even surface (every time in the same enviroment) with the z-axis up in the air.

However the initial  quaternions show different values in each cycle, even though the initial position is always exactly the same. In a measurment cycle the IMU is moved and rotated.

E.g.

Cycle 1:  q=(16381, -143, -278, 0)

Cycle 2: q=(-15826, 89, 292, -4227)

Cylce 3: q=(-16343, 217, 377, -1080)

...

What are we doing wrong?

Thanks in Advance!

[BSTRobin]

Hello M08,

I mean the calibration status value when you start to do the measurement.

[M08]

Hello BSTRobin,

My apologizies for the misunderstanding!

Our calibration status for all values is 3.

[BSTRobin]

Hello M08,

See it from your test data, euler angle showed different values when you place sensor at the same initial position.

As you used NDOF mode, what was the test environment of your product? Such as magnetic field environment.
What are the components on your PCB that will cause changes in the magnetic field?

By the way, have you compared the test data of NODF mode and IMU mode?