PIR Motion Detection Sensor - HC SR501

PIR Motion Detection Sensor Module (HC-SR501)

The HC-SR501 Passive Infrared (PIR) Sensor is a low-cost, highly reliable module for detecting human and animal motion. It works by "passively" sensing the infrared radiation (body heat) from an object. When a warm body moves within its detection range, the sensor outputs a digital HIGH (3.3V) signal. This makes it incredibly easy to use and a staple component for security systems, automatic lighting, and interactive projects. With two onboard potentiometers, you can precisely adjust the sensitivity (range) and the output time delay to perfectly match your application's needs.

🔧 Key Features

• Passive Infrared Sensing: Detects changes in infrared radiation, making it ideal for sensing people and animals while ignoring general motion.
• Wide Voltage Range: Operates on a flexible DC voltage from 4.5V to 20V, making it easy to power.
• Adjustable Sensitivity: An onboard potentiometer allows you to adjust the detection range from approximately 3 meters (10 ft) to 7 meters (23 ft).
• Adjustable Time Delay: A second potentiometer controls how long the output pin remains HIGH after motion is detected, from 5 seconds up to 5 minutes.
• Selectable Trigger Modes: A jumper allows you to select between non-repeatable (L) and repeatable (H) triggers. In H mode (default), the time delay restarts every time new motion is detected.
• Simple Digital Output: Provides a 3.3V TTL logic HIGH signal when motion is detected and LOW when idle, for easy connection to any microcontroller.
• Wide Detection Angle: The Fresnel lens provides a wide detection "cone" of approximately 110-120 degrees.

💡 Applications

• Security & Alarm Systems: A perfect trigger for burglar alarms or alert systems.
• Automatic Lighting: Automatically turn on lights in a room when someone enters and turn them off after they leave.
• Interactive Art & Displays: Create projects that react when a person approaches.
• Home Automation: Integrate with smart home systems to trigger events based on occupancy.
• Animatronics: Activate robotic or animated props when visitors get close.

⚙️ Technical Specifications

📦 Package Includes

• 1 × HC-SR501 PIR Motion Sensor Module

✅ Why Choose This Sensor?

• Extremely Easy to Use: With only three pins (VCC, OUT, GND), it's one of the simplest sensors to integrate into a project.
• Highly Adjustable: The ability to fine-tune both the range and time delay makes this sensor incredibly versatile for any motion-based task.
• Low Power Consumption: Its very low <50uA standby current makes it an excellent choice for battery-powered applications.
• Reliable & Robust: A proven, well-documented sensor used in thousands of projects worldwide.