Arduino Flame Sensor Fire Alarm Using KY-026 Sensor

 1. Introduction

Fire accidents can cause serious damage if not detected early. So, it is important to build a system that can detect fire quickly.

In this project, we are building an Arduino Flame Sensor Fire Alarm using the KY-026 sensor. This sensor detects infrared light emitted by flames.

When fire is detected, a buzzer sounds and an LED glows, giving an immediate alert.

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2. Components Required

• Arduino Uno

• KY-026 Flame Sensor Module

• Buzzer

• LED

• 220Ω Resistor

• Breadboard

• Jumper Wires

• USB Cable

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3. Circuit and Connections

Flame Sensor (KY-026)

• VCC → 5V (Arduino)

• GND → GND (Arduino)

• DO → Pin 2

Buzzer

• Positive → Pin 8

• Negative → GND

LED

• Anode (+) → Pin 13

• Cathode (–) → Resistor → GND

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4. Working Principle

The flame sensor detects infrared light from fire.

• No Flame

  • Sensor output HIGH

  • Buzzer OFF

  • LED OFF

• Flame Detected

  • Sensor output LOW

  • Buzzer ON

  • LED ON

This gives a quick alert when fire is present.

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5. Arduino Code

int flameSensor = 2;
int buzzer = 8;
int led = 13;

void setup()
{
  pinMode(flameSensor, INPUT);
  pinMode(buzzer, OUTPUT);
  pinMode(led, OUTPUT);
}

void loop()
{
  int flame = digitalRead(flameSensor);

  if(flame == LOW)
  {
    digitalWrite(buzzer, HIGH);
    digitalWrite(led, HIGH);
  }
  else
  {
    digitalWrite(buzzer, LOW);
    digitalWrite(led, LOW);
  }
}

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6. Code Explanation

The Arduino continuously reads the flame sensor.

• If flame is detected → buzzer and LED turn ON

• If no flame → both remain OFF

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7. Tips

• Adjust sensitivity using the potentiometer

• Avoid sunlight interference

• Keep sensor facing fire source

• Test using candle carefully

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8. Applications

• Fire alarm systems

• Home safety

• Industrial monitoring

• Automation projects

• Student experiments

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9. Conclusion

This project demonstrates a simple and effective fire detection system using Arduino.

It is easy to build and useful for learning sensor-based safety systems.