How to use Flame Sensor Module with Arduino

Question

This project demonstrates how to interface a flame sensor module with an Arduino to build a simple fire detection system.

How does the Flame Sensor Module Work?

The flame sensor detects the presence of a fire and activates an alarm to alert the surroundings. The working principle of the flame sensor module is based on the detection of infrared (IR) light emitted by flames. At the core of the sensor is a photodiode that captures IR radiation from hot objects like fire. The sensor also features an LM393 comparator IC, which compares the photodiode's signal against a predefined threshold set by an onboard potentiometer. If the detected IR radiation exceeds this threshold, the module's digital output (DO) changes state to indicate the presence of a flame. Additionally, the module provides an analog output (AO) that reflects the intensity of the detected IR radiation.

The flame sensor module includes several key components. The photodiode serves as the IR detector, while the LM393 comparator processes the signal. A potentiometer allows sensitivity adjustments to suit different environments. Two onboard LEDs provide visual feedback—one lights up when power is supplied, and the other indicates flame detection.

In terms of specifications, the module typically operates at 3.3V to 5V, making it compatible with most microcontrollers like Arduino. It has a detection angle of around 60 degrees and can sense flames within a range of 1 to 2 meters. Its compact design makes it easy to integrate into embedded systems and DIY electronics projects.

Flame Sensor Module Pinout

VCC (Power Supply): Connects to the 3.3V or 5V power supply.

GND (Ground): Connects to the ground (GND) of the Arduino or power source.

DO (Digital Output): Provides a HIGH (1) or LOW (0) digital signal. Output goes LOW when a flame is detected (based on threshold).

AO (Analog Output): Provides a continuous analog signal (0 to 1023 when read by Arduino).