I am using the DMP engine in the MPU9250 part to output quarternions using the eMD library. I use a dmo fifo rate of 20 Hz (default).
I notice that after power on and in stationary state the value of the quaternions being outputted is not (1,0,0,0) - (indicating zero rotation).
The initial values instead show an non trivial existing rotation eg: (0.81,0.62,0,0)
Can you explain why this is the case?
Also when quaternion data is read from the fifo, what is the order of the coordinates? I am seeing the order as: x,w,z,y
Is this the expected order?
thanks,
ben