Arduino Beginner Series: Project 12: Fire Sensor

Hello everyone!! Welcome to this post on Arduino LED Projects!!
Need a short introduction to what the Arduino is then click on LINK
Check out the breadboard intro right HERE

In this project we’ll build a fire sensor, which sounds off a buzzer and the red LED turns on when the fire sensors senses a fire nearby.


This is how my project turned out:
But this system is a super sensitive because it responds even to a candle flame cause I can’t really light up a huge flame in my house 😅😅 . Though the sensitivity can be adjusted by changing the variable resistance (just turn the gold screw-like thing on the blue box mounted on the module).

Things Required:

  1. Arduino UNO
  2. Breadboard
  3. Jumper Wires
  4. Passive Buzzer Module
  5. Fire Sensor Module
  6. LEDs (1 red and 1 green)
  7. 220 ohm resistor (x2)
  8. Arduino IDE on computer

Functions used:

  1. digitalWrite()
  2. tone()
  3. digitalRead()
  4. pinMode()
  5. delay()

Reference Material:

  1. I actually made this one on my own but here’s a really nice reference video I found for you guys to follow. (LINK). If you guys want I’ll make a video of the version that I made.


View on/ Download from Github: (LINK)

int buzzer = 10;
int redled = 9;
int greenled = 8;
int fire = 11;
int dt = 50;
int fire_state;

void setup() {
  // put your setup code here, to run once:
  pinMode(fire, INPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(redled, OUTPUT);
  pinMode(greenled, OUTPUT);


void loop() {
  // put your main code here, to run repeatedly:
  fire_state = digitalRead(fire);

  if (fire_state == HIGH) {
    digitalWrite(redled, HIGH);
    digitalWrite(greenled, LOW);
    for (int i = 450; i < 550; i++) {
      tone(buzzer, i, 100);

    for (int i = 550; i > 450; i--) {
      tone(buzzer, i, 100);

  }  else {
    digitalWrite(redled, LOW);
    digitalWrite(greenled, HIGH);


Stay Tuned for upcoming posts on Arduino Projects! We’re on the basic newbie projects right now and slowly, gradually move on to those cool, ultra techy projects!! Want to be the first to know when a new and amazing post comes up?? Then feel free to subscribe!

Happy Learning!!

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