HCSR501 Infrared PIR Motion Sensor Module for Arduino and Raspberry Pi Quick overview The HCSR501 is a compact passive infrared motion sensor module that detects moving heat sources and provides a dependable digital output for microcontroller projects. It is designed for easy integration with Arduino, Raspberry Pi, and most other development boards. Key benefits Reliable motion detection: Detects humanscale movement to trigger lights, cameras, alarms, or automation routines without continuous polling by your controller. Easy integration: Simple threepin interface for VCC, ground, and digital output so you can connect quickly to breadboards and headers. Tunable behavior: Onboard adjustments let you set detection sensitivity and output hold time, reducing false triggers and adapting performance to different environments. Low power and compact: Small PCB with a focused Fresnel lens keeps power use minimal and fits into tight enclosures and prototypes. Versatile compatibility: Works with Arduino, Raspberry Pi, ESP series controllers, and most microcontrollers that accept a digital input. What it does Senses changes in infrared radiation emitted by moving objects in its field of view and switches its digital output accordingly. Offers selectable trigger modes so you can choose singleshot or repeatable detection behavior. Allows adjustment of detection range and delay time via onboard potentiometers for precise control. Key attributes Function: Passive infrared motion detection with digital output Compatibility: Designed to work with Arduino and Raspberry Pi and other microcontroller platforms Size and form factor: Compact PCB module with integrated Fresnel lens for focused detection Material: PCB with standard electronic components and plastic sensor lens Performance: Adjustable sensitivity and timing to balance range, responsiveness, and false trigger reduction Typical applications Automatic lighting: Turn hallway or porch lights on only when someone enters the area, conserving energy and simplifying wiring. Security and camera trigger: Wake cameras, start recording, or activate alarms when movement is detected for eventdriven monitoring. Home automation and IoT projects: Use as presence detection for HVAC control, smart switches, or interactive installations. Quick setup tips Connect VCC, ground, and output to the appropriate pins on your controller. Use the onboard potentiometers to tune sensitivity and delay time to match your environment. Configure the trigger mode jumper for single or continuous detection behavior as needed. The HCSR501 module provides a practical, lowcost motion sensing solution for prototyping and deployment where simple, reliable motion detection is required.