HCSR501 Human Body Infrared Sensor Module with Pyroelectric Probe Why this module matters Detects human motion reliably so devices respond only when needed, reducing manual effort and unnecessary power use. Simple digital output makes it easy to add motion sensing to projects without complex signal processing. Adjustable sensitivity and timing let you tune detection for different spaces and use cases. Key benefits Readytouse motion sensing: Builtin pyroelectric infrared probe and Fresnel lens detect moving warm bodies and provide a clear digital output. Easy integration: Threepin interface for power, ground, and output works with common microcontrollers and control boards. Tunable performance: Two onboard potentiometers adjust detection distance and hold time, plus a mode jumper for repeat or singletrigger behavior. Compact and durable: Small PCB and plastic lens keep the module lightweight and easy to mount in tight spaces. Low resource requirements: Designed for lowpower projects and batterypowered systems. Main features and specifications Model: HCSR501 human body infrared sensor module. Sensing element: Pyroelectric infrared probe with plastic Fresnel lens. Detection range: Adjustable, typically up to several meters depending on environment and sensitivity setting. Detection angle: Broad field suitable for room and corridor coverage. Interface: 3pin VCC, GND, OUT digital output compatible with common microcontrollers. Adjustable controls: Sensitivity (distance) potentiometer, time delay potentiometer, and mode selection jumper for repeat or nonrepeat triggering. Size and material: Compact PCB board with plastic lens; suitable for mounting in hobby and prototype enclosures. Typical use voltage: Operates from common DC supply voltages used in microcontroller projects. Compatibility Designed for straightforward use with microcontroller platforms and single board computers such as Arduino, Raspberry Pi, ESP8266, and similar logiclevel controllers. Works with a wide range of control systems that accept a digital /low input for motion detection. Practical applications Automatic lighting: Turn lights on when a person enters a room and off after a set interval to save energy and improve convenience. Security and monitoring: Trigger alarm systems or notification routines when motion is detected in a protected area. Smart home and automation: Integrate into occupancy sensing, HVAC control, or appliance automation to create responsive living spaces. How it solves common problems Replaces manual switching by providing an automatic trigger for lights and devices. Reduces false triggers by allowing sensitivity and delay tuning for different environments. Loweffort integration into prototypes and finished products thanks to a simple digital output and compact form factor. What you get A preassembled HCSR501 module ready for immediate testing and integration into hobby, education, or prototype projects. This module is suited for hobbyists, educators, and developers who need dependable motion sensing that is easy to configure and integrate into a variety of applications.