Spiral

This is a demonstration of my Replay Football system. It employs a Nerf football with a 9-axis inertial sensing motion processing module with integrated Bluetooth and a visualization / throw analysis application on an Android platform. The football transmits the real-time motion data via Bluetooth. A Motorola Droid 2 was used for the Android platform. The 9-axis inertial sensing motion processing module an MPU-6000 by http://www.invensense.com

Once a throw/catch pair have been detected, the football graphic turns red and the program enters replay mode. To replay the throw, the user performs a tap motion on the screen to start playback. The throw release speed, time in flight, RPM of spiral and spiral wobble (precession) are all displayed during playback. The 3 graphs ( from top to bottom) display the raw data from the Accelerometer, Gyro, and Magnetometer respectively. A long-press on the screen resets the state back to 'green' to accept a new throw for analysis.

Complete project details are available at: http://www.kokes.net/imufootball/imufootball.htm

EDIT: The guy on the right is a actually a really good athlete. I asked him to throw a poor pass so that the graphic on the phone would wobble around.