The **F-R02** is a widely used **Photoelectric Flame Sensor Module**. It is designed to detect the presence of fire or light sources with wavelengths ranging from 760nm to 1100nm. It is commonly integrated into fire-fighting robots, alarm systems, and safety monitoring devices. --- ### 1. Key Electronic Components The F-R02 module consists of several critical electronic parts that work together to convert light energy into a measurable electrical signal. | Component | Function | | :--- | :--- | | **Infrared (IR) Receiver** | A high-sensitivity photodiode that reacts to the infrared radiation emitted by a flame. | | **LM393 Comparator** | An integrated circuit (IC) that compares the sensor voltage against a reference voltage to provide a clean digital output. | | **Potentiometer** | A variable resistor (blue trim-pot) used to adjust the sensitivity threshold of the sensor. | | **Status LEDs** | Two LEDs: One for "Power" (indicating the board is on) and one for "Digital Output" (lighting up when a flame is detected). | | **Resistors & Capacitors** | Passive components used for signal conditioning and noise reduction. | --- ### 2. Technical Specifications Understanding the electrical limits is essential for connecting the F-R02 to a microcontroller like Arduino or Raspberry Pi. | Feature | Specification | | :--- | :--- | | **Operating Voltage** | 3.3V to 5V DC | | **Detection Angle** | Approximately 60 degrees | | **Spectral Range** | 760nm ~ 1100nm | | **Output Type** | Dual Output (Analog and Digital) | | **Current Consumption** | ~15mA | --- ### 3. Pinout Configuration The F-R02 typically features 4 pins for easy interfacing: 1. **VCC**: Power input (3.3V - 5V). 2. **GND**: Ground connection. 3. **DO (Digital Output)**: Outputs a **High** signal when no flame is detected and a **Low** signal when a flame is detected (logic depends on the specific module revision). 4. **AO (Analog Output)**: Provides a real-time voltage signal proportional to the intensity of the flame/IR light. --- ### 4. How it Works 1. **Sensing:** The photodiode captures infrared light. Flames emit a significant amount of IR radiation in the 760-1100nm band. 2. **Processing:** The signal goes to the **LM393**. If the signal exceeds the threshold set by the **Potentiometer**, the Digital Output (DO) flips state. 3. **Integration:** The **Analog Output (AO)** can be connected to an ADC (Analog-to-Digital Converter) to measure the distance or size of the flame based on intensity. ---