Sorry for the question duplication, but I've spent hours googling, and just have no idea where to start. Just started an iPhone augmented reality application project, and stuck. The accelerometer data provided this way - http://www.tuaw.com/2007/09/10/iphone-coding-using-the-accelerometer/". The other problem is to get the data in 360 degrees. The best would be a site/article/post/anything that explains me the whole problem/solution from the ground up, but if there is any "ready-made" formula with all the trigonometry, would appriciate as well. If there's any advice, please don't hesitate to share with me, thanks in advance.