Arduino GSM Project: Security Alert message to multiple numbers

(Last Updated On: July 17, 2019)

Arduino GSM Project

Description:

Arduino GSM Project: Security Alert message to multiple numbers-

In this tutorial, you will learn how to make an Advanced security system and send the Security Alert message to multiple numbers using Arduino and A GSM Sim900A Module. For the demonstration purposes, I will be using an LDR, which makes this project as the laser security system, but if you want you can also replace the LDR with a PIR sensor or Magnetic reed switch Sensor or a limit switch and so on. You can also use multiple sensors.

This is basically the 2nd version of the GSM laser security system in which I used the LDR sensor for the intruder detection and I used the same GSM sim900A module. in this project, the security alert message is only sent to one number. If you want to watch this Tutorial Click Here

But in many situations, we need to send the same security alert message to multiple numbers. So this tutorial is all about how to write a very simple program and how to connect all the components together to make the advanced security system. In this tutorial, we will cover

  1. GSM SIM900A module Pinout explanation
  2. Complete Circuit Diagram
  3. Programming and finally number
  4. Testing

For the step by step explanation watch Video tutorial Click Here


The components and tools used in this project can be purchased from Amazon; the components purchase links are given in the description.

Arduino Uno: https://amzn.to/2tVz1vu

Mega 2560: https://amzn.to/2ze1kdu

GPS module: https://amzn.to/2LqzyPO

Sim900A: https://amzn.to/2Nv70TI

5V regulated power supply/Adaptor for GSM sim900A: https://amzn.to/2u10V9a

Super Starter kit for Beginners https://amzn.to/2KJvmKG

Jumper Wires: https://amzn.to/2KMoVXs

Bread Board: https://amzn.to/2MS4q8X

12v Adaptor: https://amzn.to/2Ntr6h1

PCB plate: https://amzn.to/2IUwpCt

Variable Supply: https://amzn.to/2MT4Qfj

Digital Multimeter: https://amzn.to/2Nvft9i

Vero Board / stripboard: https://amzn.to/2MTf9jD

Soldering iron kit:  “best”  You guys should definitely purchase this

https://amzn.to/2zfoNuJ

Solder wire: https://amzn.to/2ufUMWf

Wire Stripper: https://amzn.to/2KOqxfU

wirecutter: https://amzn.to/2ucIq14

PCB small portable drill machine: https://amzn.to/2Nu62XF

GSM SIM900A module pinout:

Arduino GSM Project: Security Alert message to multiple numbers

Arduino GSM Project

This is the GSM sim900A module, in the market, we have different types of GSM modules, the one I will be using today is sim900A if you want you can also use any other gsm module, like for example sim900D. I have also tested the same programming using sim900D but with a different baud rate, the rest of the program remains the same.


If you are from Pakistan, Bangladesh or India make sure you double-check the GSM module and purchase the unlocked version of the sim900A module. This GSM sim900A module as you can see on the screen has no Onboard voltage regulator, so be careful while applying the voltage. Ideal voltage for this GSM module is 4.7v but you can also connect it with a 5v adaptor. If you don’t have a 5v adaptor then you can make your power supply using an lm317t adjustable variable voltage regulator, I have a very detailed tutorial on lm317t explaining everything Click Here” If in case you want to watch this tutorial.

As you can see clearly in the picture above this module has so many pins which are clearly labeled, but we will be using only 5 of these pins, the power supply pins, GND, Rxd 5v, and TXD 5v. The GND will be connected with the Arduino’s GND, TXD will be connected with the Arduino’s pin number 7 and RXD will be connected with the  Arduino’s pin number 8.


Arduino GSM Project – Circuit Diagram:

Arduino GSM Project

This schematic is designed in Cadesoft eagle 9.1.0 version, if you want to learn how to make schematics and PCB’s then you watch my tutorial Click Here

Tx of the sim900A is connected with pin number 7 of the Arduino, the Rx pin of the sim900A module is connected with pin number 8 of Arduino and GND is connected with the Arduino’s ground. a power supply is connected with the sim900A module ideal voltage is 4.7v to 5v as already explained.

An LDR is connected in series with a 10k resistor which makes a voltage divider circuit. As you know an LDR is basically a variable resistor, whose resistance changes with the amount of light falling on the LDR. So a change in resistance will result in a change in voltage. This change in voltage can be monitored using the analog pin A1 of the Arduino.


Interfacing:

Arduino GSM Project

All the components are interfaced as per the circuit diagram, this is the LDR circuit, as you can see an LDR is connected in series with a 10k resistor. A wire from the middle of the LDR and 10k resistor is connected with the analog pin A1 of the Arduino.

The GSM sim900A module Txd and Rxd pins are connected with the Arduino pin number 7 and pin number 8, and make sure you connected the ground of the gsm module with the ground of the Arduino. This GSM module will be powered up using this Regulated 5v power supply. Now let’s discuss the Arduino Programming.

Programming:

Arduino GSM Project: Security Alert message to multiple numbers

For the step by step program explanation watch video tutorial Click Here

Watch Video Tutorial:

Arduino GSM Project: How to send Security Alert message to multiple numbers using gsm module

 

Other GSM-based Projects:

How to use GSM and Bluetooth Together To monitor Any Sensors wirelessly using Arduino

 

RFID & GSM based student Attendance Alert message to parents

 

Request Temperature Data Using GSM and Arduino

 

Arduino and Gsm based laser security system

 

Car accident location tracking using GSM, GPS, and Arduino

 

GSM Alarm System Using Arduino and a PIR Sensor

 

Arduino Gas leakage detection and SMS alert MQ-2 sensor

 

RFID based students attendance system with message Alert

 

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About the Author: Engr Fahad

My name is Shahzada Fahad and I am an Electrical Engineer. I have been doing Job in UAE as a site engineer in an Electrical Construction Company. Currently, I am running my own YouTube channel "Electronic Clinic", and managing this Website. My Hobbies are * Watching Movies * Music * Martial Arts * Photography * Travelling * Make Sketches and so on...

1 Comment

  1. Hello 🙂
    I need Your help.
    I saw Your code about multiple sms send and I created this program code:

    #define sensor 7

    #include <SoftwareSerial.h>
    SoftwareSerial SIM800(11, 12); // gsm module connected here
    String textForSMS;

    // cell numbers to which you want to send the security alert message
    String f1001 = “+48694377xxx”;
    String f1002 = “+48509168xxx”;

    void setup() {

    randomSeed(analogRead(0));
    Serial.begin(9600);
    SIM800.begin(9600); // original 19200. while enter 9600 for sim900A
    Serial.println(” logging time completed!”);
    pinMode(sensor, INPUT_PULLUP);
    delay(5000); // wait for 5 seconds

    }

    void loop() {

    {
    textForSMS = “\nIntruder detected”;
    //sendSMS(textForSMS);
    sendsms(textForSMS, f1001); // you can use a variable of the type String
    Serial.println(textForSMS);
    Serial.println(“message sent.”);
    delay(5000);

    sendsms(“Intruder Detected!!!!!!!!!”, f1002); // you can also write any message that you want to send.
    Serial.println(textForSMS);
    Serial.println(“message sent.”);
    delay(5000);

    }
    }

    But it’s not working, please tell my why? I use module SIM800L: https://robu.in/wp-content/uploads/2017/09/GSM-MODULE-SIM800-5V.jpg
    On serial port monitor I see every command from program arduion.

    Please help me with this, and answer for email 🙂
    Thank You very much.

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