#include <Arduino.h>
#include <ESP32Servo.h>

const int potPin = A0;         // Connect the potentiometer output to pin A0 on the Arduino Uno
const int buzzerPin = 8;       // Connect the buzzer to pin 8 on the Arduino Uno
const int servoPin = 9;        // Connect the servo to pin 9 on the Arduino Uno
const int gasSensorPin = 1;   // Connect the gas sensor to analog pin 1 on the Arduino Uno

Servo gasDetector;             // Create a servo object

void setup() {
  Serial.begin(9600);          // Initialize serial communication
  pinMode(buzzerPin, OUTPUT);  // Set buzzer pin as output
  gasDetector.attach(servoPin);    // Connect the servo object to the servo pin
}

void loop() {
  int potValue = analogRead(potPin);  // Read value from potentiometer
  Serial.print("Potentiometer Value: ");
  Serial.println(potValue);            // Send potentiometer value via serial communication
  
  int gasValue = analogRead(gasSensorPin); // Read value from gas sensor
  Serial.print("Gas Sensor Value: ");
  Serial.println(gasValue);             // Send gas sensor value via serial communication
  
  // If gas sensor value exceeds a certain threshold, move the servo to turn off the gas regulator
  if (gasValue > 800) { // Change the threshold value according to your gas sensor characteristics
    gasDetector.write(0);   // Move servo to 0 degree position (e.g., to turn off the gas regulator)
    delay(1000);        // Wait for a moment to ensure servo movement
  } else {
    // If no gas leakage, move servo according to potentiometer value
    int angle = map(potValue, 0, 1023, 0, 180); // Map potentiometer value to servo angle
    gasDetector.write(angle);                        // Rotate servo according to potentiometer value
  }
  
  if (Serial.available() > 0) {      // If there is data available on the serial port
    String message = Serial.readStringUntil('\n'); // Read received data from Arduino Uno
    Serial.print("Gas Detected: ");
    Serial.println(message);                    // Print received data from Arduino Uno
  }
  
  Serial.println("Gas Detection!");  // Send "Gas Detection" message from Arduino Uno
  
  // Generate sound on buzzer based on potentiometer value
  tone(buzzerPin, potValue);    // Generate sound with frequency based on potentiometer value
  
  delay(1000); // Delay for 1 second before reading again
}