Homemade Laser Triggered Booby Trap

In this tutorial we will be building a laser triggered booby trap that can be used as a home defense system. This project can be setup in doorways and on doors to catch intruders off guard and give you time to get the jump on them!


  • Laser diode https://amzn.to/2VVBAwP
  • Laser receiver https://amzn.to/2HlSQ6k
  • pnp transistor https://amzn.to/2HkGbjX
  • 3.7 volt battery
  • gearbox motor
  • PCB from PCBWAY

To start off we get the emitter pcb and attach a 3.7 volt battery to it, a switch and the laser diode. The PCB can be ordered from pcbway . At the moment PCBway is also having their I Can Solder competition where you create something with their PCBs and can win up to $800 so be sure to check that out.

Once the emitter is complete we must build the receiver. the receiver consists of the laser detecting module plugged in to the PCB . We also add a battery, motor and PNP transistor to the PCB to complete it.


once the emitter and receiver are complete the project can be tested out. turning the laser on and shinning it at the receiver will cause the motor not to rotate. When the laser breaks connection with the receiver, the motor will start to rotate. Once we have the laser component working we can start to build the booby trap mechanism. For this we glue a few popsicle sticks together and use some office supplies to build a catapult mechanism.

To complete the project we can mount a motor with a Popsicle stick attached to the shaft. Arrange the catapult in a way that the motor’s Popsicle stick blocks it . When the motor starts to rotate the popsicle stick will stop blocking the catapult and allow the payload to be launched at the intruder.


Specially thanks to PCBWay for sponsoring these boards for my project.

Also PCBWAY is having a promotion where PCB assembly fee drops from $88 down  to $30 for SMT prototype orders that quantity is within 20 sets and total number of parts is within 600 pcs.  Check it out here