GSM Based Fire Alarm System

GSM, Microcontroller Based Fire detection and SMS Alert system, it uses LM35 Temperature Sensor and MQ2 for Smoke sensing and 16x2 LCD is used to display temperature and Smoke Level, Over limit set points are set inside the program you can modify it as per your requirements, It Sends SMS when set limits are crossed through GSM modem that is attached to Serial Rxd and Txd  Pins, Set your mobile number inside the code in SendSMS subroutine. It generates Sound When Fire is detected for alerting.

Features:
1. Disconnects Electrical Supply as soon as Fire is detected
2. Sends Fire Alert SMS with Temperature and Smoke Level to Given number.
3. Makes Loud Sound using buzzer to alert about fire.
4. Uses Standard MQ2 Smoke Sensor and LM35 Temperature Sensor 
5. Low Cost

This project is very useful for Monitoring of temperature, smoke level, It gives SMS Alert as soon as fire is detected.

In this project GSM Modem, MQ-2, LM35 are main parts. You can try this project using Protius simulation. Circuit diagram, Layout is provided with code. Download respective files.

Simulation View:

Step 1: Components Required
1. Atmega 8 Microcontroller
2. LM35 Temprature Sensor

3. MQ2 Smoke Sensor
4. 16x2 LCD
5. BC548
6. 1K Ohm Resistors
7. GSM Modem (SIM300 or SIM900)

8. Buzzer

Step 2: Circuit Design and PCB Manufacturing
Download Requires Files
1. Try Simulation Click Here to Download Protius Simulation File
2. Download pdf Complete Circuit Diagram

3. Download pdf PCB Layout

4. Download pdf Component Placement Diagram
5. Assemble components using above files.

Step 3: Programming the controller
Download Hex File (You need to change phone number in code to get SMS)
AVR Studio C Code

//=================================================================
/* Fire Detection and SMS Alert System      */
/* 2nd Dec 2005                             */
/* Copyright 2005 Circuits4You.com          */ 
/* WWW - http://www.circuits4you.com        */
/* Email - info@circuits4you.com            */
//=================================================================
#include <avr/io.h>
#include <string.h>

#define E   PD7
#define RS   PB0

void display(char string[16], char LineNo);
void displaybyte(char D);
void dispinit(void);
void epulse(void);
void delay_ms(unsigned int de);

void USART_Transmit(char data );
void senddata(char string[16]);
void USART_Init();
void USART_Receive();
void sendSMS();

 char mystr[6];
 int Temperature,setpoint,Smoke,SmokeSet;
 unsigned char u8_data;
//=================================================================
//        Main Function
//=================================================================
int main(void)
{
 setpoint=60;  //Temprature Limit For detection of Fire
 SmokeSet=100; //Smoke Setpoint
 char Flag;

 DDRB = 0xF1;  //Set LCD Port Direction   
 DDRD = 0xE0;
 PORTB = 0x06; //Pull up for switches

  delay_ms(500);  //Initiaize LCD
  dispinit();
  delay_ms(200);

 USART_Init();  //9600 Baud rate at internal ocillator Clock 1MHz

 display("Temperature:32 C",1);
 display("Smoke:55 PPM    ",2);
  while(1)
  {
    //Measure Temprature and Display
    ADMUX=0xE5;
    ADCSRA=0xC7;  //Internal Referance 2.56V
    while (!(ADCSRA & (1<<ADIF)));
    Temperature=ADCH;
    ADCSRA |= 1<<4;
    sprintf(mystr, "%03d", Temperature);
    display("Temperature:",1);
    displaybyte(mystr[1]);
    displaybyte(mystr[2]);
    displaybyte(0xDF);
    displaybyte('C');
    displaybyte(0x20);

    ADMUX=0xE4;   //Smoke Sensor
    ADCSRA=0xC7;  //Internal Referance 2.56V
    while (!(ADCSRA & (1<<ADIF)));
    Smoke=ADCH;   //Do some math here for calibration
    ADCSRA |= 1<<4;
    sprintf(mystr, "%03d", Smoke);
    display("Smoke:",2);
    displaybyte(mystr[0]);
    displaybyte(mystr[1]);
    displaybyte(mystr[2]);
    displaybyte('P');
    displaybyte('P');
    displaybyte('M');
    displaybyte(0x20);

  //Compare with Set Points and Send SMS
  if(Temperature>setpoint || Smoke>SmokeSet) 
  {
   //Over Temprature SMS
     if(Flag==0)
     {
    sendSMS();
    Flag=1;
    PORTB &=~(1<<PB5);  //Turn of  Electrical Supply
    PORTB |=(1<<PB4);  //Turn on buzzer 
     }
  }
  else
  { 
   Flag=0;
   PORTB |=(1<<PB5);   //Keep on Electrical Supply
   PORTB &=~(1<<PB4);   //Turn off buzzer 
  }
  }
}

//=================================================================
//        LCD Display Initialization Function
//=================================================================
void dispinit(void)
{
 int count;
 char init[]={0x43,0x03,0x03,0x02,0x28,0x01,0x0C,0x06,0x02,0x02};
  
 PORTB &= ~(1<<RS);           // RS=0
 for (count = 0; count <= 9; count++)
  {
 displaybyte(init[count]);
  }
 PORTB |= 1<<RS;    //RS=1
}


//=================================================================
//        Enable Pulse Function
//=================================================================
void epulse(void)
{
 PORTD |= 1<<E;
  delay_ms(1); //Adjust delay if required
 PORTD &= ~(1<<E);
 delay_ms(1); //Adjust delay if required
}


//=================================================================
//        Send Single Byte to LCD Display Function
//=================================================================
void displaybyte(char D)
{
//D4=PD6
//D5=PD5
//D6=PB7
//D7=PB6
 //data is in Temp Register
  char K1;
  K1=D;
  K1=K1 & 0xF0;
  K1=K1 >> 4;  //Send MSB
  
  PORTD &= 0x9F;  //Clear data pins 
  PORTB &= 0x3F;
  
  if((K1 & 0x01)==0x01){PORTD |= (1<<PD6);}
  if((K1 & 0x02)==0x02){PORTD |= (1<<PD5);}
  if((K1 & 0x04)==0x04){PORTB |= (1<<PB7);}
  if((K1 & 0x08)==0x08){PORTB |= (1<<PB6);}

 epulse();

  K1=D;
  K1=K1 & 0x0F;  //Send LSB
  PORTD &= 0x9F;  //Clear data pins 
  PORTB &= 0x3F;

  if((K1 & 0x01)==0x01){PORTD |= (1<<PD6);}
  if((K1 & 0x02)==0x02){PORTD |= (1<<PD5);}
  if((K1 & 0x04)==0x04){PORTB |= (1<<PB7);}
  if((K1 & 0x08)==0x08){PORTB |= (1<<PB6);}
 epulse();
}

//=================================================================
//        Display Line on LCD at desired location Function
//=================================================================
void display(char string[16], char LineNo)
{
 int len,count;

 PORTB &= ~(1<<RS);           // RS=0 Command Mode

 if(LineNo==1)
 {
  displaybyte(0x80);  //Move Coursor to Line 1
 }
 else
 { 
  displaybyte(0xC0);  //Move Coursor to Line 2
 }
 PORTB |= (1<<RS);           // RS=1 Data Mode



  len = strlen(string);

   for (count=0;count<len;count++)
  {
    displaybyte(string[count]);
 }
}


//=================================================================
//        Delay Function
//=================================================================
void delay_ms(unsigned int de)
{
unsigned int rr,rr1;
   for (rr=0;rr<de;rr++)
   {
  
  for(rr1=0;rr1<30;rr1++)   //395
  {
   asm("nop");
  }
   
   }
}


void USART_Transmit(char data )
{
 UDR = data;
 /* Wait for empty transmit buffer */
 while ( !( UCSRA & (1<<UDRE)) )
 ;
 /* Put data into buffer, sends the data */
 
}


void senddata(char string[16])
{
  int len,count;
  len = strlen(string);

   for (count=0;count<len;count++)
  {
    USART_Transmit(string[count]);
 }
}

void USART_Init()
{
/* Set baud rate */
 UBRRH = 0x00;  //12, 9600 Baud At 1MHz
 UBRRL =12; 
//Set double speed enabled 
  UCSRA |= (1<<U2X);
/* Enable receiver and transmitter */
 UCSRB = (1<<RXEN)|(1<<TXEN);
/* Set frame format: 8data, 2stop bit */
 UCSRC = (1<<URSEL)|(1<<USBS)|(3<<UCSZ0);
//Set interrupt on RX
//  UCSRB |= (1<<RXCIE);
}

void USART_Receive()
{
/* Wait for data to be received */
while ( !(UCSRA & (1<<RXC)) )
;
/* Get and return received data from buffer */
u8_data=UDR;
} 

void sendSMS()
{
     senddata("AT+CMGD=1");
     USART_Transmit(13);
     USART_Transmit(10);
     delay_ms(1000);
          
     senddata("AT+CMGF=1");
     USART_Transmit(13);
     USART_Transmit(10);
     delay_ms(1000);
     
     senddata("AT+CMGW=");
     USART_Transmit(34);
     senddata("+91xxxxxxxxxx");  //Enter Your Mobile number
     USART_Transmit(34);
     USART_Transmit(13);
     USART_Transmit(10);
     delay_ms(1000);
     
     senddata("Alert: Fire Detected");
     USART_Transmit(13);
     USART_Transmit(10);
     delay_ms(1000);
     senddata("Temperature:");
     
     ADMUX=0xE5;
     ADCSRA=0xC7;  //Internal Referance 2.56V
     while (!(ADCSRA & (1<<ADIF)));
     Temperature=ADCH;
     ADCSRA |= 1<<4;

     sprintf(mystr, "%03d", Temperature);
     USART_Transmit(mystr[1]);
     USART_Transmit(mystr[2]);
     USART_Transmit('C');
     USART_Transmit(13);
     USART_Transmit(10);

     senddata("Smoke Level:");
     ADMUX=0xE4;   //Smoke Sensor
     ADCSRA=0xC7;  //Internal Referance 2.56V
     while (!(ADCSRA & (1<<ADIF)));
     Smoke=ADCH;   //Do some math here for calibration
     ADCSRA |= 1<<4;
     sprintf(mystr, "%03d", Smoke);
     USART_Transmit(mystr[0]);
     USART_Transmit(mystr[1]);
     USART_Transmit(mystr[2]);
     USART_Transmit('P');
     USART_Transmit('P');
     USART_Transmit('M');
     USART_Transmit(13);
     USART_Transmit(10);


     delay_ms(1000);
     USART_Transmit(26); //Cntrl+Z
     delay_ms(1000);
     delay_ms(1000);

     senddata("AT+CMSS=1");
     USART_Transmit(13);
     USART_Transmit(10);
     delay_ms(1000);
}

Step 4: Test the code and Hardware
1. Change temperature and Smoke level and observe the relay on/off, Buzzer operation.
2. LCD display Should show the message as shown in simulation results.
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4. You Did it Yourself
5. Refer Tutorials from this site for more understanding of code and Circuits