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Arduino and Gsm based laser security alert system programming


laser security system


This tutorial is based on the Arduino and GSM sim900A unit Laser Security system. This tutorial demonstrates step by step how to use the Arduino, LDR and sim900A GSM module to build your own GSM-based laser security system. Arduino Uno or Mega will perform the main processing. We will make our own circuit based on LDR’s light resistor for laser detection.’

This project can be easily modified by incorporating other sensor styles such as:

ground sensors

 PIR Sensor 

Magnetic Reed, etc.

The Amazon purchase links are given in the description.

GPS module:
Arduino Uno:
Mega 2560:
lm7805 Voltage Regulator:
330-ohm resistors pack:
female DC power jack socket:
470uf capacitors:
5√ó7 cm Vero board:
female headers:
connection wires:
Super Starter kit for Beginners:
Jumper Wires:
Bread Board:
12v Adaptor:
PCB plate:
Variable Supply:
Digital Multimeter:
Vero Board / stripboard:
Soldering iron kit: ‚Äúbest‚ÄĚ You guys should definitely purchase this:
Solder wire:
Wire Stripper:
PCB small portable drill machine:


Please Note: these are affiliate links. I may make a commission if you buy the components through these links. I would appreciate your support in this way!

SIM900A gsm Module:

laser security system


When the voltage is applied because the GSM sim900A module does not have an integrated voltage regulator as you can see on the monitor. The optimal voltage for this GSM device is 4.7v but you can also link it to a 5v adapter. If you don’t have a 5v adaptor, you can use a lm317 t variable voltage regulator to make your power supply. There¬† are¬† so¬† many¬†pins¬†in¬†the¬†GSM¬†module,¬†as¬†you¬†can¬†see¬†clearly¬†in¬†the¬†picture¬†above,¬†but¬†we¬†use¬†only¬†5,¬†the¬†power¬†supply¬†pins,¬†GND,¬†Rxd¬†5v,¬†and¬†TXD¬†5v.¬†The¬†GND¬†is¬†connected¬†to¬†the¬†Arduino¬†GND,¬†the¬†Arduino¬†pin8¬†is¬†connected¬†to¬†the¬†TXD¬†and¬†the¬†Arduino¬†pin8¬†is¬†connected¬†to¬†the¬†RXD.

laser security system Circuit Diagram:

laser security system


In series, an LDR is connected to a 10k resistor making a circuit for the voltage divider. As you know, an LDR is simply a variable resistor that adjusts its resistance with the amount of light falling on the LDR. Thus a resistance change will result in a voltage change. This voltage shift can be tracked using the Arduino’s analog pin A1.

laser security system Programming:

Watch Video Tutorial

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  1. I need a laser based security system using gsm module, IR sensor and Arduino project { mainly I need Circuit diagram & code}

    1. bro, i already replied to your comment on my Youtube channel, “Electronic clinic”. I have already did this project, it’s available on
      all you need open my other website make a search, you will get all the related projects with circuit diagrams and codes.

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