Arduino punch force sensor

[lazy-slob]

Hi All,

I’m wanting to make a punch power meter reader like funfairs have.

Currently I’ve got an ADXL345 accelerometer connected to Arduino Uno. I’ve run a the following sample sketch that gives me reading on X, Y & Z from the serial monitor to test the device works but I want to be able to measure force.

Arduino Accelerometer using the ADXL345

What I want is to be able to place the sensor in a pad then when hitting it I get a number which increases when hit harder. Ideally have it display onto a digital display.

Optionally if I solve this it would be cool to add other modes like reading reaction time. For example an LED or sound is played and based on how soon you hit it a number shows the response time from serial monitor and led screen.

Can anyone put me in the right direction on where to start?

Regards

Dave

[jremington]

The accelerometer measures only acceleration, which is change in velocity over time.

If you know the mass of the object that is being accelerated, force (in Newtons) = (mass in kg)*(acceleration in m/s^2).

[gilshultz]

You can use a load sensor and you need to add a method to save the peak voltage. There are circuits that do just that, called peak and hold pr peak detector.

This is a link to the circuit complete with explanation: Planet Analog - Peak Detector: A Classic Analog Circuit Still in Wide Use