Me and my wife are building our ninth escape room. We want to have a real cool riddle for the final puzzle, where the players obtain a gun(a BB gun actually) complete with laser scope.
We want the players to point the laser scope against the lock of a door and fire the gun, the door will then open(as if its lock is shot out).
I was thinking of hiding a LRD in the lock, and have it check for a laser beam. However this would easily be triggered by some flash light or something, so I am looking for tips on something else that would only open with the gun and not anything else.
Most lasers are monochromatic while most flashlights produce white light. If you put colored filters over several photoresistors you can get a rough idea of the light's color and select for only certain colors.
You could try looking for a bandpass filter that complements your laser and photocell. I've used https://www.edmundoptics.com/ for industrial stuff, but it might give you a starting point to work from. You could also try having the laser emit at a given frequency using tone and then measure the incoming photocell lights frequency? I've never tried that though.