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Fire Alarm System

Detect flames and sound an alarm with a red LED.

beginner25 min

Components Needed

Arduino UNO

Flame sensor module

Buzzer

Red LED + 220Ω

Circuit Diagram & Wiring

Add your circuit diagram image here.

Flame sensor DO → pin 2, VCC → 5V, GND → GND.
Buzzer → pin 8.
LED → pin 9 via 220Ω.

Arduino Sketch (.ino)

fire-alarm.ino

const int FLAME = <span style="color:#79b8ff">2span>, BUZ = <span style="color:#79b8ff">8span>, LED = <span style="color:#79b8ff">9span>;

void setup() {
  pinMode(FLAME, INPUT);
  pinMode(BUZ, OUTPUT);
  pinMode(LED, OUTPUT);
  Serial.begin(<span style="color:#79b8ff">9600span>);
}

void loop() {
  bool fire = digitalRead(FLAME) == LOW;
  digitalWrite(LED, fire);
  if (fire) {
    tone(BUZ, <span style="color:#79b8ff">1200span>, <span style="color:#79b8ff">200span>);
    Serial.println(<span style="color:<span style="color:#f97583">#9ecbffspan>">&quot;FIRE!&quot;span>);
  } else {
    noTone(BUZ);
  }
  delay(<span style="color:#79b8ff">100span>);
}