As the ultimate anti-theft alarm device in sci-fi movies, laser alarm device has its invisible infrared ray available for experience and utilization, allowing you to catch the thief easily… Actually, it can be also used in this way.

Step 1:

Your pet at home may be disobedient or go to a prohibited place. Why not making a laser anti-theft alarm emitter if you have no time to guard it?

Step 2:

Today, I will introduce a simple laser alarm device model to you.

Principle: A laser emitter sends a light beam and another laser receiver receives the laser beam. When the connection is established, the alarm will be triggered if any object blocks the laser beam.


DFRduino UNO R3(similar as Arduino UNO R3

Gravity:Digital RED LED Light Module

Gravity: Digital Buzzer For Arduino

Laser Transmitter

Toggle Switches

9V battery

Jumper Wires


Step 3:

Measure relevant dimensions of laser emitter and receiver with vernier caliper and record such dimensions for using during user modeling.

Step 4:

Support of laser reception terminal

Step 5:

Base of laser reception terminal

Step 6:

Finished installation of reception terminal

Step 7:

Installation of receiver

Step 8:

Support of laser emission terminal

Step 9:

Support base of laser emission terminal

Step 10:

Support and support base

Step 11:

Switch installation

Step 12:


Step 13:

Insertion of support into the support base

Step 14:

Completion of emitter terminal

Step 15:


If you think one is not enough, you may make multiple alarm devices!

Step 16: