Flame Sensor Module for Arduino and Microcontrollers
= Infrared-Based Fire Detection Sensor =
The flame sensor module is a lowcost, highly sensitive device that detects fire by sensing the infrared spectrum emitted by flames. It uses an infrared receiver (phototransistor) to detect light in the wavelength range of 760nm to 1100nm, making it ideal for fire alarm systems, firefighting robots, and flame-finding projects with Arduino and other microcontrollers .
Dual Output Modes - Provides both analog (AO) and digital (DO) outputs for flexible integration
Adjustable Sensitivity Onboard potentiometer allows finetuning of the digital output threshold
Operating voltage is 3.3V to 5.3V, compatible with most microcontrollers
The sensor module uses an LM393 comparator to provide a clean digital output signal
The digital output is active LOW - it outputs 0V when a flame is detected
The sensor detects infrared radiation and is sensitive to sunlight and other hot objects, which may cause false alarms
= Technical Specifications =
| Parameter | Value |
|---|
| Detectable Wavelength | 760nm - 1100nm |
| Detection Angle | Up to 60 degrees |
| Detection Distance | 20cm to 100cm (varies with flame intensity) |
| Operating Voltage | 3.3V to 5.3V |
| Output Types | Analog (AO) and Digital (DO) |
| Comparator IC | LM393 |
| Operating Temperature | -25°C to +85°C |
= Key Features =
+Infrared Detection - Sensitive to the infrared radiation emitted by flames, particularly around 940nm
+Adjustable Sensitivity - Onboard potentiometer for setting the digital output threshold
+High Response Speed - Response time of approximately 15µs for fast detection
+Comparator Output - LM393 comparator provides clean digital signal with status LED indicator
== Applications ==
- Fire detection and alarm systems
- Fire-fighting robots for finding fire sources
- Flame tracking and fire source localization
- Safety monitoring systems for homes and industries
LowCost Solution Affordable and widely available sensor for fire detection projects
Easy Integration - Simple wiring and compatibility with Arduino, ESP32, and other MCUs
√ Onboard power and signal LEDs for status monitoring
√ Mounting holes for secure installation
√ Potentiometer for adjusting digital output sensitivity
= Connection Guide (Arduino) =
| Sensor Pin | Arduino Pin | Function |
|---|
| VCC | 5V | Power supply |
| GND | GND | Ground |
| DO | Digital Pin | Digital output (LOW when flame detected) |
| AO | Analog Pin | Analog reading (intensity/distance) |
Connect DO to a digital pin to detect flame presence (LOW = flame detected)
Use AO with analogRead() to measure flame intensity or distance
Keep the sensor at a safe distance from flames to avoid damaging the module
= Troubleshooting =
Sensor not detecting flame:
- Adjust the sensitivity potentiometer on the module
- Check that the sensor is facing the flame source
- Ensure the flame is within the detection range (20cm to 100cm)
False triggers:
- Reduce sensitivity by adjusting the potentiometer
- Avoid direct sunlight or strong infrared sources near the sensor
- Use the analog output for more precise intensity measurements
No output:
- Verify 5V power and GND connections
- Check wiring to DO or AO pins
