Gas leakage detector using Arduino with SMS alert | Gas Detecting Alarm ...

Code:-

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x3F, 16, 2); 

int temp=0,i,pos ;

String stringVal = "";

const char offMessage[] = "Alarm off";

const char activeMessage[][16] = {"Gas Detected", "Please evacuate"};

const int piezo = 10;

const int gasSensor = A0;

int gas;

void setup(){

    pinMode(piezo, OUTPUT);

    pinMode(A0,INPUT);  

  Serial.begin(9600);

   lcd.begin();

  lcd.backlight();

  lcd.print("Gas Leakage DTctr");

  lcd.setCursor(0,1);

  lcd.print(" with SMS Alert ");

// lcd.scrollDisplayLeft();    //scrolls display left by two positions

   delay(4000);

  gsm_init();

  lcd.clear();  

  Serial.println("AT+CNMI=2,2,0,0,0");

  delay(300);

   lcd.print("System Ready");

  temp=0;

}

void loop()

{ 

  int gas_level=readSensors();

  lcd.clear();

       if(gas_level>60)

       {

        setActive();

        init_sms();

        send_sms();

        lcd_status();

       }

       else

       {

        setOff();

       }

}

void gsm_init()

{

  lcd.clear();

  lcd.print("Finding Module..");

  boolean at_flag=1;

  while(at_flag)

  {

    Serial.println("AT");

    delay(1);

    while(Serial.available()>0)

    {

      if(Serial.find("OK"))

      at_flag=0;

    }

    

    delay(1000);

  }

  lcd.clear();

  lcd.print("Module Connected..");

  delay(1000);

  lcd.clear();

  at_flag=1;

  while(at_flag)

  {

    Serial.println("AT+CMGF=1");

    delay(1);

    while(Serial.available()>0)

    {

      if(Serial.find("OK"))

      at_flag=0;

    }

    

    delay(1000);

  }

  lcd.clear();

  lcd.print("TEXT MODE..");

  delay(1000);

  lcd.clear();

  lcd.print("Disabling ECHO");

  boolean echo_flag=1;

  while(echo_flag)

  {

    Serial.println("ATE0");

    while(Serial.available()>0)

    {

      if(Serial.find("OK"))

      echo_flag=0;

    }

    delay(1000);

  }

  lcd.clear();

  lcd.print("Echo OFF");

  delay(1000);

  lcd.clear();

  lcd.print("Finding Network..");

  boolean net_flag=1;

  while(net_flag)

  {

    Serial.println("AT+CPIN?");

    while(Serial.available()>0)

    {

      if(Serial.find("+CPIN: READY"))

      net_flag=0;

    }

    delay(1000);

  }

  lcd.clear();

  lcd.print("Network Found..");

  delay(1000);

  lcd.clear();

}

void init_sms()

{

  Serial.println("AT+CMGF=1");

  delay(400);

  Serial.println("AT+CMGS=\"mobile number\"");   // use your 10 digit cell no. here

  delay(400);

}

void send_sms()

{

  Serial.println("Gas leakage found");   // use your 10 digit cell no. here

  Serial.print("Leakage level : ");

  Serial.println(gas);

  Serial.write('%');

  Serial.println(activeMessage[1]);

  delay(400);

  Serial.write(26);

}

void lcd_status()

{

  lcd.clear();

  lcd.print("Message Sent");

  delay(2000);

  lcd.clear();

  lcd.print("System Ready");

  return;

}

int readSensors()

{

  int q = analogRead(gasSensor);

 gas = map(q, 10, 1023, 1, 100);

  return gas;

}

void setActive()

{

 tone(piezo, 750);

 lcd.setCursor(0, 0);

 lcd.print(activeMessage[0]);

 lcd.setCursor(0, 1);

 lcd.print(activeMessage[1]);

 delay(2500);

}

void setOff() {

 noTone(piezo);

 lcd.setCursor(2, 0);

 lcd.print(offMessage); 

 lcd.setCursor(2, 1);

 lcd.print("GAS LVL : ");  

 lcd.print(gas);

 lcd.write('%');

 delay(500);

}