Fire Alarm with arduino

Flame Sensor

A flame detector is a sensor designed to detect and respond to the presence of a flame or fire. Responses to a detected flame depend on the installation but can include sounding an alarm, deactivating a fuel line (such as a propane or a natural gas line), and activating a fire suppression system. The IR Flame sensor used in this project is shown below, these sensors are also called Fire sensor modules or flame detector sensors sometimes.

There are different types of flame detection methods. Some of them are Ultraviolet detector, near IR array detector, infrared (IR) detector, Infrared thermal cameras, UV/IR detector, etc.

When fire burns it emits a small amount of Infra-red light, this light will be received by the Photodiode (IR receiver) on the sensor module. Then we use an Op-Amp to check for a change in voltage across the IR Receiver, so that if a fire is detected the output pin (DO) will give 0V(LOW), and if the is no fire the output pin will be 5V(HIGH).

In this project, we are using an IR-based flame sensor. It is based on the YG1006 sensor which is a high speed and high sensitive NPN silicon phototransistor. It can detect infrared light with a wavelength ranging from 700nm to 1000nm and its detection angle is about 60°.  The flame sensor module consists of a photodiode (IR receiver), resistor, capacitor, potentiometer, and LM393 comparator in an integrated circuit. The sensitivity can be adjusted by varying the onboard potentiometer. Working voltage is between 3.3v and 5v DC, with a digital output. A logic high on the output indicates the presence of flame or fire. A logic low on output indicates the absence of flame or fire.

Below is the Pin Description of the Flame sensor Module:

Pin	Description
Vcc	3.3 – 5V power supply
GND	Ground
Dout	Digital output

Circuit Diagram

CODE

int buzzer = 8;

int LED = 7;

int flame_sensor = 4;

int flame_detected;

void setup()

{

  Serial.begin(9600);

  pinMode(buzzer, OUTPUT);

  pinMode(LED, OUTPUT);

  pinMode(flame_sensor, INPUT);

}

void loop()

{

  flame_detected = digitalRead(flame_sensor);

  if (flame_detected == 1)

  {

    Serial.println("Flame detected...! take action immediately.");

    digitalWrite(buzzer, HIGH);

    digitalWrite(LED, HIGH);

    delay(200);

    digitalWrite(LED, LOW);

    delay(200);

  }

  else

  {

    Serial.println("No flame detected. stay cool");

    digitalWrite(buzzer, LOW);

    digitalWrite(LED, LOW);

  }

  delay(1000);

}