title: How to use gyro z axis on the iPhone?
body: <p>I'm using the gyro (does accelerometer and gyro the same on iPhone?) and the X axis and Y axis are working great.</p>
  
  <p>The Z axis is called YAW, but I just can't understand it. It should change its value to 0 when iPhone on its sides and -1 to 1 when face up and down.</p>
  
  <ol>
  <li>In reality , every move on the X/Y axis , change also the Z ...</li>
  <li>The definition of Z is answer also on the definition of X axis anyway (same?) because Z is not discrete .</li>
  </ol>
  
  <p>I just can't understand the Z axis thing and if there is another way of getting data of current position from iPhone except from this.</p>