GSM Based Fire Alert System with Text Message & Buzzer Indication

Share This

Hello friends! Welcome back to ElectroDuino. This blog is based on GSM Based Fire Alert System using Arduino and SIM800 GSM Module. Here we will discuss Introduction to GSM Based Fire Alert System, Project Concept, Block Diagram, Components Required, Circuit diagram, Working Principle, and Arduino Code.


Every day, we hear of fire accidents happening somewhere. It takes the lives of many people and damages huge property. Most of the damages in fire accidents occur due to a lack of early fire detection, it is a very big problem. So, here we will try to solve this problem with the help of smart technology. In this project, we will learn how to make a GSM Based Smart Fire Alert System, which alerts us when the fire started. This system alerts us by sending a text message/SMS to a specific user’s Mobile number and generates sound to warn the people who are present at the accident spot. This system can save many lives and protect from property damage. We can use this system at the office, building, bank, school, factory, shopping mall, etc. places.

Project Concept of GSM Based Fire Alert System

This GSM Based Fire Alert System project concept is very simple and it’s very easy to build. The main components of this project are the LM35 Temperature Sensor, Arduino, SIM800L GSM Module, LCD Display, LED, and Buzzer.

The LM35 is a Temperature Sensor IC, its output voltage change according to the change of temperature around it. Here it is used to measure the temperature of surroundings. When a fire accident occurs, then it detects high temperature and provides a high output voltage. This output voltage goes to the Arduino. Here we will use Arduino NANO which is the main microcontroller of this project, it controls the whole system. The Arduino calculates the temperature using the sensor output. When the Arduino detects more than normal temperature, then it sends commands to the GSM module for sending a Text Message/SMS to a specific user’s Mobile number. The LED and Buzzer are working as a fire indicators. We can see the temperature on the LCD Display.

Block Diagram of GSM Based Fire Alert System

Block Diagram GSM Based Fire Alert/ Alarm/Detector System with Text Message & Buzzer & LED indication using Arduino, LM35 Temperature Sensor, SIM800L GSM Module
Block Diagram of GSM Based Fire Alert System using Arduino

Components Required 

Components NameQuantity
Arduino Nano1
LM35 Temperature Sensor1
SIM800L GSM Module1
16×2 LCD Display Module1
Red LED (D1)1
Green LED (D1)1
Buzzer (B1)1
1000µf 50V Capacitor1
Slide Switch (SW1)1
9V Battery with Battery connector1
4.1 v Power Supply1
PCB Zero board1
Connecting wiresAs required in the circuit diagram


Tools Required

Tools NameQuantity
Soldering Iron1
Soldering wire1
Soldering flux1
Soldering stand1
Desoldering pump1

Circuit Diagram of GSM Based Fire Alert System


Note: SIM800L GSM Module operate on 3.7v-4.4v Power supply. 5v power supply can be destroy the module. So here we are using an 4.1v 2A power supply, which ideal for the module.


For more details: SIM800l GSM Module

Working Principle of GSM Based Fire Alert System

After connecting all components according to the circuit diagram and uploading the code to the Arduino board, now turn on the circuit power supply. Then the Arduino starts working step by step according to the code.

In the beginning, the Arduino makes the connection to the Network through the SIM800L GSM Module. At the same time, the LM35 temperature sensor starts to sense the temperature around it and generates analog output voltage. Its output voltage change according to the change of temperature. The Arduino read this voltage and calculates the temperature in Degrees Celsius (°C) by the following formula which is used in Arduino code.

Temperature = [{(output voltage * 5.0) / 1024}*100.0] °C

When a fire accident occurs, then the room temperature is also increased. Due to this, the output voltage of the LM35 Temperature sensor is also increasing. The Arduino reads this output voltage and calculates the room temperature.

When the room temperature is cross 55°C then the Arduino sends a “Fire Alert!!” message to a particular phone number through the GSM module (you can change the message text and phone number in Arduino code). At the same time, the Red LED and buzzer also turn on, these warn people inside the room and the fire alert message also print on the LCD Display.

During the normal condition the room temperature is less than 50°C then the Arduino detects there is no fire. This time the Green LED will be turned on and the “No Fire! Safe Now” message print on the LCD Display.

Arduino Code


Share This

Leave a Reply

Your email address will not be published.