I want to make a 4x4 set of cups which have holes in the bottom and lead into a chamber at the bottom of the base. The user will throw a ping pong ball and try to make it into one of the cups. If the ball successfully falls through the cup, it goes into the chamber. In my basic plan, I am planning to connect 16 sensors (1 for each cup) and 16 LEDs (again 1 for each cup) to a raspberry pi which will update a web server on which cup caught the ball and then light up the corresponding cup. My question is, what type of sensor would be the best to recognize whether a ping pong ball fell into a cup or not? Any suggestions would be appreciated, thanks!
No need for individual sensors. Instead, make the bottom transparent; aim a camera at the cup bases. Use opencv running on the Pi to detect the objects and tally them.
For the lights, use an addressable RGB strip. You can singulate the lights physically as needed to mount them next to the the cups.