The **HW-R** series typically refers to a family of **Infrared (IR) Flame Sensor Modules** commonly used in Arduino and robotics projects to detect fire or light sources within the 760nm to 1100nm wavelength range. Below is an explanation of the electronic components and technical specifications for these modules. --- ### 1. Key Electronic Components The module functions by converting light energy into an electrical signal. Here are the primary parts found on the PCB: | Component | Function | | :--- | :--- | | **Infrared Receiver (Photodiode)** | The black LED-like component. it is sensitive to infrared light (flame) and changes its conductivity based on light intensity. | | **LM393 Comparator** | An integrated circuit (IC) that compares the voltage from the photodiode against a reference voltage to provide a clean digital output. | | **Potentiometer (Trimmer)** | A small blue knob used to adjust the sensitivity threshold of the sensor. | | **Status LEDs** | Usually two: one for power (Power LED) and one that lights up when a flame is detected (Digital Output LED). | | **Resistors/Capacitors** | Passive components used for current limiting and signal filtering to ensure stability. | --- ### 2. Pinout Configuration Most HW-R flame sensors have a 3-pin or 4-pin interface: 1. **VCC:** Power supply (typically 3.3V to 5V). 2. **GND:** Ground connection. 3. **DO (Digital Output):** Outputs a HIGH or LOW signal (TTL logic) based on whether a flame is detected. 4. **AO (Analog Output):** (On 4-pin versions) Outputs a real-time voltage value representing the intensity of the infrared light. --- ### 3. Technical Specifications | Parameter | Value | | :--- | :--- | | **Detection Angle** | Approximately 60 degrees | | **Spectrum Range** | 760nm ~ 1100nm | | **Operating Voltage** | 3.3V - 5V DC | | **Output Type** | Digital (0 and 1) and Analog | | **PCB Size** | ~3.2cm x 1.4cm | --- ### 4. Basic Connection Example (Arduino) To read the digital state of the sensor, you can use the following logic: ```cpp int flamePin = 2; // Digital pin connected to DO int val = 0; void setup() { pinMode(flamePin, INPUT); Serial.begin(9600); } void loop() { val = digitalRead(flamePin); if (val == LOW) { // Usually LOW when flame is detected Serial.println("FLAME DETECTED!"); } delay(100); } ``` ---