The HC-SR501 Human Infrared Sensor (Blue Plate) is a reliable PIR motion sensor module designed to detect human body movement using passive infrared technology. It senses changes in infrared radiation emitted by moving objects, making it ideal for motion detection applications.

This module features a blue PCB variant and includes adjustable sensitivity and delay time controls, allowing customization based on the application. It provides a digital output signal when motion is detected, enabling easy integration with Arduino, Raspberry Pi, and other microcontrollers.

Equipped with a Fresnel lens for enhanced detection, the HC-SR501 offers a wide detection range and stable performance. It is commonly used in automatic lighting systems, security alarms, and smart home automation.