5 pieces SR501 HCSR501 Adjustable PIR Motion Sensor Modules Overview A pack of five SR501 HCSR501 passive infrared motion detector modules. Each module uses a pyroelectric infrared sensor and integrated Fresnel lens to detect motion. Adjustable controls let you tailor sensitivity and hold time for a wide range of projects and installations. Key benefits Reliable motion detection: Passive infrared sensing detects moving heat sources without emitting signals, making the module suitable for presence detection and event triggering. Adjustable operation: Builtin adjustment controls allow you to set detection sensitivity and output delay to match your application and reduce false triggers. Easy integration: Standard module format and simple power and signal connections make these modules straightforward to add to microcontroller and control systems. Compact and lightweight: Small PCB and lens assembly fits into tight spaces and can be mounted in prototypes, enclosures, or fixtures. Batch convenience: Supplied as a set of five modules for parallel installations, multisensor coverage, or spare parts for development. Functions and attributes Function: Passive infrared motion detection using a pyroelectric sensor and Fresnel lens. Adjustability: Useraccessible controls for sensitivity and timing allow tuning for different distances and durations. Compatibility: Designed for hobby and professional electronics projects; compatible with common microcontroller and control boards and with typical digital input circuits. Physical: Compact PCB module with plastic Fresnel lens and header pins for power and signal connections. Performance: Provides a digital motion output suitable for triggering alarms, lights, relays, or microcontroller inputs. Typical applications Automatic lighting: Turn lights on when motion is detected and off after a programmed delay to save energy in corridors, closets, or stairwells. Security and monitoring: Detect unauthorized movement for basic intrusion alerts or to trigger cameras and recording systems. Automation and robotics: Use as a presence sensor for robots, interactive displays, or smart appliances to respond to human movement. What you receive Five SR501 HCSR501 PIR motion detector modules, adjustable and ready for integration into development boards, sensor arrays, or standalone circuits. Notes Modules are intended for electronic and control applications. Confirm pinout and power requirements in your setup before connecting.