Introduction: Flame Detector With Arduino

About: Hello, my name is Carlos. I have a YouTube channel where I share my projects in

In this project we will create a fire or flame detector with arduino and the sensor ky-26, this optical flame sensor, allows to detect the existence of combustion by the light emitted by fire.

It is called fire to the group of particles or incandescent molecules of combustible matter, capable of emitting visible light, product of a chemical reaction of violent oxidation. The flames are the parts of the fire that emit visible light.

Step 1: Dangers

Fire involves a set of dangers, the first and most obvious are burns. Also others such as smoke inhalation poisoning.

This project tries to create an economic device that helps to prevent fires or their early detection to try to save lives and economic goods, such as building structures, merchandise, documents, etc.

Step 2: About the Flame Detector Module

  • This module is sensitive to a flame and its radiation. It can also detect ordinary light source in the range of a wavelength from 760 nm to 1100 nm.
  • The flame sensor can emit digital or analog signal.
  • It can be used as a fire alarm. Detection of an angle of about 60 degrees, particularly sensitive to the spectrum of the flame.
  • Adjustable sensitivity (in blue adjustment of the digital potentiometer).
  • The comparator output, clean signal, good wave, driving capacity, more than 15mA.
  • Operating voltage of 3.3 V-5 V. The output form: digital switching outputs (0 and 1) and analog voltage output AO.
  • Fixed bolt holes for easy installation.
  • Small PCB boards Size: 3.2cm x 1.4cm.
  • Use an LM393 amplifier as a voltage comparator

Step 3: Use of the Module

  • A small output interface board can be connected directly to the microcontroller
  • The sensor and the flame have to maintain a certain distance, in order not to damage the sensor by temperature
  • The flame of a lighter has been tested at a distance of 80 cm.
  • Small analog output boards and with an AD conversion processor, you can get higher accuracy.

Step 4: Spectrum of a Flame

The emission spectrum of a flame depends on the elements involved in the reaction. In the case of combustion of products with carbon in the presence of oxygen, we have two characteristic peaks in ultraviolet at wavelengths of 185nm-260nm and in infrared at wavelengths 4400-4600nm.

Step 5:

Flame sensors are widely used in the industry. Many machines execute processes that can generate flames, such as machining or EDM processes. Frequently they are made in the presence of combustible elements such as oil or shavings.

For this reason, call sensors are incorporated as a safety device, allowing the process to be stopped in case of detecting any indication of combustion. These devices adjust to the wavelengths characteristic of the appearance of the flame and usually combine the ultraviolet and infrared signals.


Flame detector

Step 7: Arduino Uno

Step 8: Buzzer

Step 9: Dupont Wire

Step 10: CIRCUIT


int buzzer = 11; //select the pin for the buzzer

int valorSensor = 0; // variable to store the value coming from the sensor

void setup() {

//Setting the serial port speed


// declare buzzer as a output

pinMode(buzzer, OUTPUT);

} void loop() {

//Read the sensor value:

valorSensor = analogRead(A0);


//activate the buzzer

if (valorSensor < 500){

digitalWrite(buzzer, HIGH);


// Desactiva el buzzer

digitalWrite(buzzer, LOW);

delay(50); }



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Step 13:

Arduino Contest 2017

Participated in the
Arduino Contest 2017