Using the iPhone’s Accelerometer

The iPhone was the first mass-market device to use accelerometers for user-interface interaction: switching between Landscape and Portrait modes. The iPhone provides a remarkably easy-to-use API.

How Accelerometers Work

Accelerometers measure the acceleration they experience. For instance, if you’re sitting in a plane that’s taking off, you feel your back pressed into the chair in the direction opposite to the one you’re traveling in. Accelerometers measure this force. If you lie on your back, you’ll also feel your back pushing into the bed. Accelerometers also measure this force.