Sudden Motion Sensor

© Amit Singh. All Rights Reserved. Written in Februrary 2005

Core Articles

The Sudden Motion Sensor describes the original applications that use the orientation data retrieved from the built-in motion sensor in Apple's notebook computers.

The Sudden Motion Sensor As A Human Interface Device describes how to use the motion sensor as a general purpose input device.

SMS Software

Caveats

At some point, axes y and z were "switched" beginning with a certain hardware model. Motion sensor applications that depend on the original relationship of the axes will not work as expected on such hardware, until I can get around to updating them.

Moreover, on the new hardware, for the same range of motion, more discrete values are retrieved (that is, the "sensitivity" is higher). Therefore, programs that rely on the magnitude and/or sign of these values will have to be recalibrated.