Our project is to drive a toy car over the platform. Platform is consists of 49 squares , 7 on the edge of the platform. 7x7. Each square is 14x14cm and 3mm thick. They are rougly a couple of grams. Our goal is to use these squares as interactive tiles. Each square(tile) has a neopixel underneath. We are numbering these tiles from 1 to 49. For example, systems selects a tile. It will be lit green. And then toy car try to go over that green lit tile. So we need to know if that car is above that tile. To know that we need to scan and name each tile individualy. We are struggling with the system that detects the car. We are now trying to use buttons under each tile. But buttons are so hard to push that car will not push it while going above the tile. So we need a system that will be easy for car to push it while going above the tile. Also it needs to be cost effective. We considered using LDRs and buttons. We need different ideas.
Edit: We need to use maximum 3-4 digital pins for it. System will include other accessories.