int buzzer = 8; 
int LED = 7;  
int flame_sensor = 4; 
int flame_detected;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(buzzer, OUTPUT);
  pinMode(LED, OUTPUT);
  pinMode(flame_sensor, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  flame_detected = digitalRead(flame_sensor);
  if (flame_detected == 1) {
    Serial.println("Phat hien ngon lua...!");
    tone(buzzer, 1000, 500);
    digitalWrite(LED, HIGH);
    delay(200);
    digitalWrite(LED, LOW);
    delay(200);
  }
  else{
    Serial.println("Khong co lua phat hien");
    noTone(buzzer);
    digitalWrite(LED, LOW);
  }
  delay(1000);
}