Core Location and Core Motion device heading <p>I've noticed one problem with Coree Motion. When I'm using the</p> <pre><code> [_mMotionManager startDeviceMotionUpdatesUsingReferenceFrame: CMAttitudeReferenceFrameXTrueNorthZVertical toQueue: [[[NSOperationQueue alloc] init] autorelease] withHandler: ^(CMDeviceMotion* motion, NSError* error) { //my code here }]; </code></pre> <p>to get device motion it gives me wrong device heading. I mean if I start processing motion updates holding device towards the north the heading is OK. But if I start not towards the north the bias is very big.</p> <p>Is there any way to get correct values of heading?</p>