// Define sensor pins
const int smokeSensorPin = A0; // Analog pin for MQ-2 sensor
const int flameSensorPin = 2;  // Digital pin for flame sensor
const int buzzerPin = 9;       // Buzzer for alarm

// Threshold values for smoke and fire detection
const int smokeThreshold = 300; // Adjust based on your sensor calibration
const int flameThreshold = LOW; // Flame sensor typically outputs LOW when flame is detected

void setup() {
  // Initialize serial communication for debugging
  Serial.begin(9600);
  
  // Set sensor pin modes
  pinMode(smokeSensorPin, INPUT);
  pinMode(flameSensorPin, INPUT);
  pinMode(buzzerPin, OUTPUT);

  // Start with buzzer off
  digitalWrite(buzzerPin, LOW);
}

void loop() {
  // Read sensor values
  int smokeValue = analogRead(smokeSensorPin);
  int flameValue = digitalRead(flameSensorPin);

  // Display sensor values on the serial monitor
  Serial.print("Smoke Level: ");
  Serial.print(smokeValue);
  Serial.print(" | Flame Detected: ");
  Serial.println(flameValue == LOW ? "YES" : "NO");

  // Check if smoke level exceeds the threshold or flame is detected
  if (smokeValue > smokeThreshold || flameValue == flameThreshold) {
    // Trigger the buzzer
    digitalWrite(buzzerPin, HIGH);
    Serial.println("ALERT! Smoke or Fire detected!");
  } else {
    // Turn off the buzzer if no danger
    digitalWrite(buzzerPin, LOW);
  }

  // Add a small delay for stability
  delay(500);
}