title: Get values from either Gyroscope or Accelerometer
body: <p>I am trying to build an application wherein I need only the device rotation values. I want the application support to be as low as possible, so my preference would be to read the values from Gyroscope first if the device has its hardware (iPhone 4) or get the values from Accelerometer (iPhone 3G &amp; 3GS).</p>
  
  <p>I would like to write a RotationManager class which would handle interacting with either Gyroscope or Accelerometer, its internal operation will be abstract for the rest of the application. How do I design the RotationManager class? What are the things that should be considered in order to build a good reusable RotationManager instance?</p>
  
  <p>Thanks,</p>
  
  <p>Raj</p>