Instructables

Build Your Own Laser Trip Wire

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- Ever wanted to catch an intruder when they trip a laser beam?

- Want to know how many times your pet (or anything else) is going in and out of your house?

- Someone sneaking into a place they shouldn’t be?


- Like to play with lasers and dry ice?

This instructable teaches you how to use a laser pen, mirror, light sensor, and app to detect intruders! You can get alerts via SMS / text message, email, and the web.

Using Valarm with a Yoctopuce “Yocto-Knob” allows you to DIY a powerful, internet + SMS connected, home alarm system, by connecting your Valarm-equipped Android device to switches on windows and doors. And adding a Yocto-Light lets you take your DIY burglar alarm to a whole new level. In this How-To document we show you how to whip up an intruder alert system with a Valarm-equipped Android device, a cheap laser pen, mirror, and a Yoctopuce Yocto-Light external USB sensor.
 
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Step 1: Install and Configure

Picture of Install and Configure
This intruder alert system uses an app that can be run on small, inexpensive devices like the Sony ST25.

Install Valarm Pro on your device. Configure Valarm for the light sensor trigger by going to All Settings -> Yoctopuce -> Yocto-Meteo and Light  in Valarm Pro.

Here we’ve tested out the lumens values that the light sensor reports (use the Scan All button) and decided that if there are less than 4000 lumens (meaning something is blocking the laser from hitting the sensor) then trigger an alert. The laser will certainly be brighter 4000 lumens. Set the maximum lumens all the way to the max, so the laser doesn’t trigger alerts when in its normal ‘on’ mode. After you set the minimum trigger value for the lumens, set up any SMS/text message, email, or Valarm Tools web trigger responses you would like.
Raphango10 months ago
wow! Great one! =D
Definetely gonna do it someday! ;)
edward_Valarm (author)  Raphango10 months ago
Thank you Raphango! :) Don't hesitate to ask any questions you may have.