The Interactive Geometry Software Cinderella

Using the sudden motion sensor as gravity hardware

Starting with version 2.1, Cinderella.2 will support the sudden motion sensor hardware on Apple laptops. It can be used as "gravity hardware" in physics simulations and also in CindyScript.

The latest beta version, available from includes this code already, and we invite all Apple users to test this.

We made the Java library for reading the sensor available at

Download the beta version from (it is no problem to have both the current release version and the beta on the same machine). Choose the CindyLab toolbar using File/Choose Toolbars and create a physics simulation. Open the Inspector and select the global physics settings tab. Set the global gravity and friction to a reasonable value. Check the checkbox next to Use gravity hardware (if this is not available, and you are using an Apple laptop that includes a sudden motion sensor, please file a bug). Start the simulation and tilt your laptop...

We prepared a movie that shows all steps, and another video that shows the simulation in action:

Have Fun!

last modification: Monday 15 of January, 2007 [21:04:08 UTC]