Gas leakage circuit diagram and code

 Arduino code:

/*

  code started

  gsm lpg leakage project

  #defibe sensor = 2;

  code created by technical ideas yt

  https://youtube.com/c/TechnicalidEas07

 */

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,20,4);

int state = 0;

const int pin = 2;

void setup()

{

 lcd.init();                      

  lcd.init();

      lcd.backlight();

  lcd.begin(16,2);

 lcd.setCursor(0, 0);

 lcd.print("Hey");

 lcd.setCursor(0, 1);

 lcd.print("Innovative Army");

 delay(3000);

 lcd.clear();

  Serial.begin(9600);

 

}

void loop()

{

  if (digitalRead(pin) == HIGH && state == 0) {

    Serial.print("\r");

    delay(1000);

    Serial.print("AT+CMGF=1\r");

    delay(1000);

    //Replace XXXXXXXXXX to 10 digit mobile number

    Serial.print("AT+CMGS=\"+91XXXXXXXXXX\"\r");

    delay(1000);

    //The text of the message to be sent.

    Serial.print("Gas leakage detected");

      lcd.setCursor(0, 0);

   lcd.print(" Gas Leakage");

   lcd.setCursor(0, 1);

   lcd.print("  Detected ");

   delay(3000);

   lcd.clear();

    delay(1000);

    Serial.write(0x1A);

    delay(1000);

    state = 1;

  }

 if (digitalRead(pin) == LOW && state == 1) {

    state = 0;

  }

}