Raptor :gamedev: on Nostr: it's two plastic wheels with slots and light sensors that detect as each slot passes, ...

it's two plastic wheels with slots and light sensors that detect as each slot passes, the ball itself is just a ball that pushes them (usually by smaller rollers geared to the bigger wheels). A pretty simple machine you can build with off the shelf parts. I hated cleaning those things though, the gunk always went inside and it was a pain...