Hello, I just get interested in rotating objects without calculating angles, only with direction vectors. And I just found a way to make rotations only with accelerometer (no gyro) and a compass without any calculation of angles. If you find that it's boring and it's something original, please imforme me.
So , to know the three linear angles measuring formula in the 3 axes gyro for an object in 3 dimensional space, I think I can do this using quaternions to my theory.But as I do not know if what I just discovered is original or not, I ask you a little time to make sure (for publication) then I will give you my secret simple and easy if you n 'is in no hurry.
You can look at my first video on https://www.youtube.com/watch?v=roMkL9ANIUU&feature=em-upload_owner#action=share
or type mpu6050 & hmc5883 (NO ANGLE CALCULATION) on youtube