DIY Hacks and How Tos

DIY Hacks & How To’s: Laser Tripwire Alarm

DIY Hacks & How To’s: Laser Tripwire Alarm

No security system is complete without lasers. We have all seen movies where the main character has to get past a high tech security system and there is always a room full of lasers somewhere.

So in this project, I show you how to build a laser tripwire alarm. All you need is a cheap laser point, a couple of mirrors, and a few dollars of electrical parts. With this you can cover an entire house with an array of light beams. If any one of them is crossed it sets off your alarm. And unlike in the movies, these lasers are practically invisible.

DIY Hacks & How To’s: Proximity Sensors

DIY Hacks & How To’s: Proximity Sensors

Last week I showed how to use a pressure plate switch to activate special effects. This week, I am going to show you how to make a simple proximity sensor. This is basically just an infrared LED and a phototransistor. When a person stands near the sensor, some of the light from the LED is reflected back to the detector. The output signal of the detector can be monitored by an Arduino and used to activate special effects when the person is close enough.