I created a pair of gloves to help people keep their handshakes at a low enough pressure not to hurt people. there is a small pressure sensor in the right glove between the thumb and forefinger. The left glove has a dual color LED and a small motor which vibrates. As the pressure increases on the right hand, the motor vibration increases on the left hand proportionally. Once the pressure goes over the amount which is considered too high, the motor vibration hits the max.
The LED is used to show the state over time of the person’s handshakes. It will be green if more than half of the last 6 handshakes have been “good” (not too strong). It will be red if half or more of the last handshakes have been “bad” (too strong).
In making the pressure sensor, I ended up having to use a timer to delay measuring the pressure when the person started and stopped squeezing. This was because the pressure sensor was noisy and would jump back and forth across the threshold I had setup, resulting in multiple “handshakes” being recorded even though only one had actually occurred.