How to make a pressure sensor with buzzer on a tennis raquet grip

I'm an avid tennis player and also do a little coaching. As in most sports, when someone is under pressure they tense up causing errors. In tennis, that tension is often in the grip of the raquet. I'd like to create a tennis trainer that could be installed on a raquet that would sense the pressure being applied on the grip and when gripped to tight, would make an audible beeping sound. I don't imagine this could be applied to an individuals raquet but rather to a training raquet that I could provide. The grip pressure sensors would need to be on at least 4 (4 sides) of the 8 bevelled sides of a tennis grip. The sensors would need to be very thin and run the length of the grip (handle). The grip would still need to be usable...meaning the sensors and tape used to apply them could not cover the whole grip making it slippery or unnatural to hold. The buzzer would need to be small enough to be mounted into the throat of the raquet. There is a small triangular area on most raquests that is about 2-3 inches on each side that a small buzzer device could fit in.

I've been searching for sensors but have found nothing that is simple enough for my brain to understand. I have no idea where to get a buzzer that is so small.

I hope this is enough information. I appreaciate any ideas you can share with me.

I would look at strain gauges and force-sensing-resistors (FSR). These come in a vast variety of shapes and sizes, thin films etc. You could try just putting the sensors under that wrapping tape you can buy anywhere, or take the whole grip apart and re-wrap it with the sensors under that. Then you could cut a small groove (or not) in the shaft of the racket to run the wires and put the circuitry in that open area near the head. Small piezo beepers ("benders") are also widely available.

Maybe something from this:

https://www.kobakant.at/DIY/?p=429

https://www.instructables.com/id/Stickytape-Sensors/

"These sensors measure pressure and can also be designed and placed to measure bend. They work on the simple principal that Velostat reacts to pressure with a decrease in electrical resistance. When sandwiched between two conductive layers, this change in resistance can be easily measured and used as an indication of how much pressure is being applied."

I dont play tennis but Novak Djokovic play.

;-)

It is nice to see what effort people put in sports projects like this one. The solution is possible as shown by the ideas above, but the racket will grow in weight and for a player under stressful training I doubt the results would be useful.
To indicate hits for a remote coach I would attach a tiny bell (like those Japanese ladies love attached to their handbags) that would ring by each hit. The loudness can also indicate the grip pressure.

jiripolivka said:

It is nice to see what effort people put in sports projects like this one. The solution is possible as shown by the ideas above, but the racket will grow in weight and for a player under stressful training I doubt the results would be useful.
To indicate hits for a remote coach I would attach a tiny bell (like those Japanese ladies love attached to their handbags) that would ring by each hit. The loudness can also indicate the grip pressure.

Click to expand...

This could be done with minimal weight. The sensor(s) are a thin film, adding just about nothing to the grip. The electronics required could weigh less than an ounce (think flex circuitry).

Could you explain how a bell would indicate grip pressure?

barry said:

This could be done with minimal weight. The sensor(s) are a thin film, adding just about nothing to the grip. The electronics required could weigh less than an ounce (think flex circuitry).

Could you explain how a bell would indicate grip pressure?

Click to expand...

It will not indicate grip pressure, Such sensor and electronics will add to racquet weight an cause an unbalance. The bell can indicate hitting the ball, the force and speed, by its sound. No side effects. Try it and see for yourself. NO electronics!

jiripolivka said:

It will not indicate grip pressure, Such sensor and electronics will add to racquet weight an cause an unbalance. The bell can indicate hitting the ball, the force and speed, by its sound. No side effects. Try it and see for yourself. NO electronics!

Click to expand...

You have solved nothing. The OP has asked for a method to measure grip pressure; you have provided him/her with a cute little bell.