Coaches Studio

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Throwing Buddy
Sensor Development

Developing a proper pitching technique

IMTC researched various sensing methods to detect the speed and spin of a baseball.


Coaches Studio invented a device for teaching kids how to pitch a baseball. The current device consists of a “windsock-like” net with a captive baseball that firmly attaches to the user’s hand. The user pitches the baseball into the netting. Tell tale ribbons stitched into the device help the user to develop proper pitching technique.

IMTC researched methods to detect the speed and spin of the ball to increase interaction with the user. These sensors add the ability to detect the speed of the thrown ball and track the motion of the throwing hand.

The speed sensor was implemented using two optical proximity sensors built into the sock. The ball is detected as it passes each sensor. The time it takes for the ball to pass from one sensor to the next allows an embedded microcontroller to determine the speed of the ball.

The hand motion acquisition system was implemented with a 9 degrees-of-freedom motion sensor. This sensor acquires motion, rotation, and direction using a solid state accelerometer, gyroscope, and magnetometer.

The embedded controller communicates with a computer or cellphone via a Bluetooth SPP data connection. The raw data is saved to disk for further analysis for development in a pitch technique pattern recognition system. The pitch motion tracking system captures the motion from the movement sensors and streams the information to an attached computer.