In fact, This project work correctly with wire and push button and we can often see that difference time between 2 plauers is less than 2ms but rarely under 1ms. In addition, with the speed requested for this exercice push buttons don't live a longtime!!!!
So ma solution would be a Capacitive Touch Sensor which doesn't risk to be broken and in addition we can customize the size of the surface to touch compare to a push button.
But with the ttp223 in this case the measurement of the time is not enough correct to verify if difference time between 2 touch is under 2ms or not .
CDZ