HCSR501 Pyroelectric Infrared Human Sensor Module for Microcontrollers and Electronic Projects Overview A compact motion detection module using a pyroelectric infrared sensor and Fresnel lens to detect human movement. Designed for straightforward integration with microcontrollers and lowvoltage electronics, the HCSR501 module provides a clean digital output for triggering alarms, lighting, automation, or data logging. Key benefits Simple integration: Standard power and digital output interface makes connection to microcontrollers quick and reliable. Ideal for Arduino, Raspberry Pi, ESP series, and similar boards. Detects human motion: Pyroelectric sensing combined with a Fresnel lens detects changes in infrared radiation caused by people moving within typical room ranges, enabling responsive automation. Compact and mountable: Small PCB size and mounting holes fit inside enclosures or prototypes without taking up much space. Lowpower operation: Suitable for batterypowered and alwayson applications where modest current draw and efficient standby behavior matter. Consistent digital trigger: Produces a clear or low output that is easy to read from GPIO pins or to feed into relay and logic circuits. Important attributes Function: Passive infrared (PIR) human motion detection with digital output for eventdriven control. Compatibility: Works with most microcontrollers and development boards that accept a digital input signal and provide appropriate power rails. Size and form factor: Compact PCB module with integrated Fresnel lens and mounting hole options for easy installation in projects and enclosures. Material and construction: PCBmounted pyroelectric sensor with plastic Fresnel lens; standard throughhole or solderpad connections for power and output wiring. Performance: Responsive to human movement at room scale, suitable for detecting entry, presence, or directional motion in indoor settings. Practical applications Automatic lighting: Turn lights on when a person enters a room and off after no motion is detected, improving convenience and saving energy. Security and intrusion alerts: Trigger alarms, cameras, or notification systems when unexpected motion is detected in monitored zones. Interactive devices and automation: Use as an input for interactive installations, vending machines, appliances, or occupancybased HVAC and ventilation control. What you get A readytouse HCSR501 PIR motion sensor module that plugs into your prototype or production circuit, delivers a reliable digital motion signal, and reduces development time for motionaware electronics projects. Notes for integration Verify voltage requirements and wiring for power and output before connecting to your controller. Position the module so the Fresnel lens has an unobstructed view of the area to be monitored for detection performance. Combine with debounce logic, timers, or additional sensors if you require advanced filtering or multimodal detection.