QRotationReading interpretation

[axjensen]

I'm trying to understand the values returned by 'QRotationReading'. I can't figure out how to interpret the angles and the rotation orders. Reading the documentation, it seems like I could use the angles and combine three rotations, z, x and y. I'm uncertain whether to interpret it as an intrinsic or extrinsic rotation, and the order of rotation. Please help.

I'm assuming, that the values are calculated from the accellerometer, so it should be possible to go back from 'QRotationReading' to accellerometer values. It should be possible to rotate an [0 0 1]' vector back to what is read from the accelerometer, but I'm not having any luck with that (unless either the x or y component of the accellerometer is zero).