Arduino Newbie - Tripwire

Hi everyone, I am same as this guy, except I am a kid, and have almost no experience (unlike the other noob) I have a kit that makes a laser drive a small output pulse when broken.... Is there anyway I can connect this to arduino, have it turn the signal into something like a piezo on or led or LCD.... The kit powers itself on 9v. Sorry for intruding on this but I don't know how to make a new topic. Thanks...

Hi, what are you going to use this tripwire for? Who or what will be detected and what will happen after the piezo/led/lcd is activated?


I’m assuming we’re talking a light-beam type tripwire, not an actual wire strung across the floor.

What does the tripwire you’re trying to adapt to this currently do when triggered? It’s not clear to me from your description.

I think in the case of anything except a relay (which would be trivial to use - run ground to NO, and an IO pin to COM, set pin mode to input_pullup, and you’re pretty much good to go in terms of reading the tripwire), what you’d do is connect ground of tripwire kit to ground of the arduino, and then find a pin on the tripwire kit that changed state relative to ground when the tripwire was tripped - that’s the input to the arduino. Make sure the pin doesn’t go above 5v though - if it does, divide the voltage with a pair of resistors (ie, pin-on-kit----///—(to arduino)—////—GND so the Arduino never sees a voltage over 5v.

It’d certainly be easier if it’s output is a relay! (I know they make kits like that, since I use one)

You’ll need a volt/ohm meter for this (you should have one anyway, but it’s not even a little bit optional when you’re trying to repurpose or modify anything)