I am working in an typical projector installation. This means variable light. I want to use Arduino to detect the position of multiple people, in a square area that is aprox. 6. x 6. (meters) / 19 x 16 (feet).
I think that IR sensors are out of the questions, since light from the projector will interfere. Upon investigating, I concluded that I probably need ultrasonic sensors, however they can only sense the first obstacle and I'm not sure about their limited radius of reach, specially at closer distances (so I would need 4 for each corner).
The only thing I need is people's location, and a relatively cheap way to achieve so. I already tried with pressure sensitive mats, but it's just too many to conceal.
Any suggestions are welcome. Thanks a lot!