The **P-R11** is an industrial-grade, ultra-compact **Passive Infrared (PIR) Motion Sensor** manufactured by Panasonic (specifically within the **PaPIRs** series). It is designed for high-density, wide-area detection in smart buildings and automation systems. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Series** | PaPIRs (Panasonic PIR) | | **Detection Distance** | Up to 12 meters (standard) | | **Operating Voltage** | 3.0V to 6.0V DC | | **Current Consumption** | ~170µA (Standard) / ~1µA (Low Power) | | **Output Type** | Digital (High/Low) or Analog | | **Detection Area** | Wide-angle (approx. 90° - 110°) | --- ### 2. Electronic Architecture The P-R11 integrates several critical components into a single, TO-5 metal can package to ensure signal integrity and ease of use: #### A. Pyroelectric Element At the core is a ceramic pyroelectric material that generates an electric charge when exposed to infrared radiation (heat) from a human body. The P-R11 uses a **quad-type element** design, which improves sensitivity and reduces false triggers from small animals or sunlight. #### B. The Optical Lens (Fresnel Lens) The sensor is covered by a specialized polyethylene lens. This lens: * Collects IR rays from the environment. * Focuses them onto the internal sensors. * Determines the "zones" of detection (the P-R11 is optimized for wide-area coverage). #### C. Built-in Amplifier and Comparator Unlike older analog PIR sensors that required external Op-Amps, the P-R11 contains: * **ASIC (Application Specific Integrated Circuit):** Processes the raw micro-voltage from the pyroelectric element. * **Voltage Regulator:** Ensures stable operation even if the power supply fluctuates. * **Noise Filter:** Protects the signal from electromagnetic interference (EMI) and radio frequency interference (RFI). --- ### 3. Pin Configuration The sensor typically features three pins for straightforward integration: 1. **VDD (Power):** Connects to the positive supply (3V-6V). 2. **GND (Ground):** Connects to the system ground. 3. **OUT (Signal):** A digital output that goes "High" when motion is detected. --- ### 4. Implementation Example To interface the P-R11 with a microcontroller (like an Arduino or ESP32), you can use the following logic: ```cpp const int sensorPin = 2; // Connected to P-R11 OUT pin void setup() { pinMode(sensorPin, INPUT); Serial.begin(9600); } void loop() { int motion = digitalRead(sensorPin); if (motion == HIGH) { Serial.println("Motion Detected!"); // Trigger LED or Alarm } delay(100); } ``` --- ### 5. Common Applications * **Lighting Control:** Automatic hallway or office lighting. * **Security Systems:** High-sensitivity intrusion detection. * **Smart HVAC:** Adjusting temperature based on room occupancy. * **IoT Devices:** Battery-powered sensors due to the extremely low current draw.