I'm working on a project and I've come into a problem that has had me thinking for weeks. I need to find a way to safely detect distance, ~0-3 cm away, without much error. this is a lot to ask, but I'm fine spending 50 dollars on something like a laser if you can help me make sure it can detect distance. also, it can't touch the surface in anyway. if you have any ideas, shoot a message my way!