Introduction: SMS Fire Alarm

A number of times, a sparking in electrical wire of carelessness in the kitchen converted into fire and due to lack of consciousnesses the fire converted into disaster. Do you want to prevent your house from entering such a disaster, then this project will surely help you. This is just a basic tutorial but you can also make a tough version of it. This is a fire alarm which will notify you that their is a fire in your house through a SMS and buzzer and you should do something to prevent it. Make this project a use it in your house to protect yourself and your family. This project detects fire through a fire detecting bulb and sends a SMS and the buzzer continues to blow until the linkit one board reset button is pushed.

Step 1: Gather Parts

Here are the parts required by you to make this:

  • Linkit one
  • A SIM card
  • Fire detecting bulb
  • A buzzer
  • 10K resistor
  • Breadboard
  • Jump cables

Step 2: Insert the SIM Card

In this fire alarm, when a fire would be detected, the buzzer will blow as well as a SMS will be sent to the number mentioned in the code. This feature will help you to save your house when you out. You can choose any full size SIM card. If you have a micro SIM or nano SIM, then you can use a SIM card cover but it is better to use a full size SIM card. Place your SIM card in your linkit one. It will go inside only when way so don't panic that from which side you have to put your SIM card.

Step 3: Connect the Fire Detecting Bulb

A fire detecting bulb is a simple device made up of glass with two iron or may be steel strips inside it. When it is heated, the strips inside it expands and touch each other making the circuit complete and buzzer starts blowing. Its very cheap and very easily available. Your fire detecting bulb may be different from mine but don't panic, all works the same way. Here are its connection:

  • pin 1---linkit one 5V
  • pin 2---digital pin 4
  • short digital pin 4 and ground through a 10K resistor

Step 4: Connect the Buzzer

As I said before here a buzzer is used to aware the people in the house that their is a fire and they should take action. You can use something big like a speaker or car horn or something which makes a loud noise instead of the buzzer which gives a very faint sound. Connect negative of your buzzer to linkit one gnd and positive of the buzzer to digital pin 11.

Step 5: Upload the Code

Here is the code for the project. To check the project, you can use a matchstick. Don't check it a lot. You would use all your SIM card balance in checking only. Change the number in the code by your 10 digit phone number. Here is the code:

#include <LGSM.h>

int fire=4;

int buzzer=11;

int state=0;

void setup()







Serial.println("SIM ready for work!");


void loop()


if(digitalRead(fire)==HIGH && state=0)




LSMS.beginSMS("0123456789"); //Change your phone number from this number

LSMS.print("Fire was detected at your house!!");


Serial.println("SMS is sent");



Serial.println("SMS is not sent");




Step 6: The End

Fix it at places where you think fire can be there like your kitchen. Hope you like it. For any query or problem or for any consult,comment below. Thank you

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