Grunting Racket


Grunting Racket is a tennis racket that sounds pro tennis player’s grunting when you swing it. You can select one of the four primary active grunters, Serena, Sharapova, Djokovic, and Nadal.

*This project is on going.

Prototype #4

(12/21/2015) Appeared on DIY magazine website ‘Make:’
(1/07/2016) Interviewed by a TV program called ‘Daily Planet’ on Discovery Channel

Tech Notes
– Components are accelerometer, LiPo battery, speaker, Arduino Pro Mini, Adafruit Audio FX Sound board, power button, and player selection button.
– Designed the circuit to house all components in a thin perf board to fit in the racket’s grip.
– Basically when a value from accelerometer excesses a particular threshold, the sound board will play a tone.
– You can switch to other players whose grunting you want to hear by pressing a button on the grip.
– Here’s the link to this Git Hub Repo


Grunting… is a discharge of emotional excitement for gaining one’s win which leads to a miracle shot.


Great! Let’s make a racket that can sound those pro player’s grunting to borrow their power.


Firstly, I opened the grip of my racket to check if there is enough room to house components inside.


Fortunately, it seems Arduino Pro Mini and Adafruit FX Sound Board fits to the width, so I started making prototypes to prove the concept.


スクリーンショット 2015-10-19 16.05.00
To check the input values from accelerometer when swinging a racket, made a simple processing program to monitor those values.


The 1st prototype. Simply used an accelerometer, FX sound board and Arduino Uno connected to PC via USB cable.


The 2nd prototype. Used Arduino Pro Mini + LiPo battery to make it mobile and smaller.


Since I confirmed that this should work and fit in to the grip, started making circuit on a perf board.









This is the 3rd prototype with handmaid circuit board checking the input values from accelerometer.







Then since the board got a short circuit and had gone, I rebuild them again in a little bit sophisticated layout.







Here’s the 4th prototype that proves the concept in a clearer way.

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