Magnetometer coordinates differ testing on different devices

hey @marcod,

I'm not a 100% sure on the magnetometer, but the accelerometer also has a different range on older devices (-+2g) compared to newer (-+8g) due to better sensors (http://stackoverflow.com/a/722611). I'm guessing the same is true for the magnetometer- this demo app seems to confirm https://github.com/foundry/MagnetoMeter

Is there a reason your using the magnetometer to look around the inside of your sphere? If you want the orientation of the device you can use the 'device attitude'- and setup with either CMAttitudeReferenceFrameXMagneticNorthZVertical or CMAttitudeReferenceFrameXTrueNorthZVertical. The 'example-camera' shows how to do this.

Good luck.