Thank you all for your answers!
To summarize quickly our project, we have a campus model. When the player put his piece in a square near a building, we wanted that a video starts (on the computer) without our intervention. (the player can go to differents buildings, but each time another video starts).
So, we were thinking to use magnetic sensors to detect when and where the piece is put near a building. The magnetic sensors would be connected to a Arduino board, and the Arduino board to a laptop.
Our main problem is the installation: which components? How to connect them?
Thanks!