The **KADS-HC-R** is an infrared (PIR) motion sensor module designed for automatic lighting and security systems. It is essentially a variant of the popular HC-SR501 PIR sensor, optimized for reliability and low power consumption. Below is a breakdown of its electronic components, specifications, and pin configuration. --- ## 1. Core Electronic Components The module operates by detecting changes in infrared radiation emitted by objects (like humans). The following parts are critical to its operation: | Component | Function | | :--- | :--- | | **PIR Sensor Element** | A pyroelectric sensor (usually protected by a metal can) that detects IR radiation levels. | | **BISS0001 IC** | The "brain" of the module. It is a high-performance sensor signal processing integrated circuit. | | **Fresnel Lens** | The white plastic dome that focuses infrared energy onto the PIR element and expands the detection angle. | | **Potentiometers** | Two adjustable resistors (trimmers) used to control **Sensitivity** and **Time Delay**. | | **Voltage Regulator** | Typically a 3.3V LDO regulator that allows the module to be powered by higher voltages (e.g., 5V-20V). | --- ## 2. Technical Specifications These specifications define the electrical limits of the KADS-HC-R: * **Operating Voltage:** DC 4.5V to 20V * **Static Current:** < 50µA (Very low power consumption) * **Output Level:** High (3.3V) / Low (0V) * **Trigger Modes:** * **L (Non-repeatable):** Output stays high for the duration and then goes low, regardless of movement. * **H (Repeatable):** Output stays high as long as movement is detected within the delay period. * **Detection Angle:** < 100° cone angle * **Detection Range:** 3 to 7 meters (adjustable) --- ## 3. Pinout & Interface The module utilizes a standard 3-pin interface compatible with Arduino, ESP32, and Raspberry Pi. | Pin Name | Description | Connection | | :--- | :--- | :--- | | **VCC** | Power Supply | 5V - 20V DC | | **OUT** | Digital Signal | Connect to Microcontroller GPIO (3.3V High) | | **GND** | Ground | Common Ground | --- ## 4. Control Adjustments The back of the PCB features two orange potentiometers: 1. **Sensitivity Adjustment (Sx):** * Clockwise: Increases detection distance (up to ~7m). * Counter-clockwise: Decreases detection distance (down to ~3m). 2. **Time Delay Adjustment (Tx):** * Clockwise: Increases delay (up to ~300s). * Counter-clockwise: Decreases delay (down to ~5s). --- ## 5. Sample Wiring Logic ```cpp // Basic Arduino Logic for KADS-HC-R int pirPin = 2; // Output pin of KADS-HC-R int ledPin = 13; // Built-in LED void setup() { pinMode(pirPin, INPUT); pinMode(ledPin, OUTPUT); } void loop() { int motion = digitalRead(pirPin); if (motion == HIGH) { digitalWrite(ledPin, HIGH); // Motion Detected } else { digitalWrite(ledPin, LOW); // No Motion } } ```