Question by Let’s play froggy: How does the motion-sensing technology work for the iPhone?
Can anybody explain how the motion sensing actually works? And what device is actually used for the motion sensing?

Best answer:

Answer by Tex T
The iPhone (and the Wii as well) uses as MEMS (microelectromechanical system) called an accelerometer. The accelerometer supplies the phone with information from all 3 spacial directions making it possible for the iPhone to “figure out” where it is in space.

Since gravity and acceleration (moving the iPhone around) are the same the pull of gravity tells the accelerometer which way the iPhone is pointing.

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