How To Use Valarm, a Laser Pen, Mirror, and Light Sensor for Intruder Detection
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?
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.
1. Install Valarm Pro on your device.
2. Configure Valarm for the light sensor trigger. 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 (i.e., something is blocking the laser from hitting the sensor) then trigger an alert. The laser will certainly be brighter. Set the maximum lumens all the way to the max, so the laser doesn’t trigger alerts when in its normal ‘on’ mode. After we set the minimum trigger value for the lumens we set up any SMS/text message, email, or Valarm Tools web uploading responses we would like.
3. Now set up your scenario for the alert. Here we’ve used a laser pen from the dollar store, a Yocto-Light, and the mirror from an incredibly expensive outdoor navigation compass to bounce the laser beam and create a laser trip wire in the staircase. We just short-circuited the on-button in the laser pointer. For a long-term system, you’ll want a laser pointer powered by mains, or at least a bigger battery. You also might want to mount it with something better than duct tape (if there is such a thing in existence).
5. Here’s the Valarm scene in action! Intruders beware. (or be equipped with frozen CO2 and hot water to make the laser evident, and be very flexible to sneak through)
6. Try it out in your own scenario and let us know how it goes (ten.mralavnull@ofni)! Or perhaps you want to use the light sensor for your hydroponics, garden, aquaponics, or any other place to know when the lights go on or off or when the light levels go above or below your custom level. See the Valarm blog for other posts such as how to use Valarm for remote home monitoring or water detection and flood alerts.