I need help to map a wall


#1

Can someone guide me how can I solve the following problem?

We have a wall with a projection, the projection is divided into grids. The user will hit with a racket a ball that makes impact in one of the projected grids, the system has to detect in which quadrant the ball has made an impact, in order to show another video in the projection.

I can think of different solutions with Arduino but I think they are not optimal, any suggestions?

Thank you!


#2

May be you could share your ideas… are you thinking about some sort of sensor on the wall or are you oriented on a camera and video processing? That would be tough if the wall has some video going on it…

You could use a conductive ball and build a grid of wires on the wall and detect the short between a given row and column, like the old keypads… or a few microphones at the back of the wall to detect vibrations, then calculate the position from the different delays. Whatever the solution it is not going to be a trivial task, I suppose, but looks interesting.

regards
Davide


#3

maybe an IR camera with high framerate and well illuminated along with some CV might get the work done.
the microphone triangulation works quite well too, and it is not hard to build. Just place one piezo sensor on each corner and connect to an arduinos analog input. then run a simple beat detection (just using a threshold) and triangulate the position based on the time difference between the hits detected by each microphone.