Pack of 10 SR501 HCSR501 adjustable pyroelectric infrared PIR motion sensor modules designed for straightforward integration into electronic and automation projects. Key benefits Reliable motion detection: Senses changes in infrared radiation caused by moving people or objects and provides a clean digital output for control circuits. Adjustable behavior: Onboard controls let you tune sensitivity and trigger delay to reduce false alarms and match each installation. Easy integration: Simple threepin wiring and standard output make these modules compatible with common microcontrollers and control systems. Compact and lightweight: Small PCB and molded Fresnel lens fit into tight enclosures and prototype boards. Consistent performance: Designed for lowpower standby operation and reliable switching when motion is detected. What this module does and how it helps Detects human or largeobject movement and supplies a digital signal to drive relays, LEDs, alarm inputs, or microcontroller pins. This removes the need for continuous manual monitoring and enables automated responses. Adjustable sensitivity and timeout controls let you minimize nuisance triggers from pets, small movements, or environmental changes while ensuring consistent detection when needed. Its compact form allows deployment in multiple locations to automate lighting, activate cameras, or control ventilation based on occupancy. Important attributes Function: Pyroelectric infrared sensor with digital output that changes state when motion is detected. Controls: Onboard potentiometers for sensitivity adjustment and output duration (time delay). Compatibility: Works with common development boards and controllers such as Arduino and Raspberry Pi, as well as automation and security systems that accept a digital input. Size and material: Small printed circuit board with a molded Fresnel lens sensor assembly; lightweight for easy mounting. Performance: Designed for practical indoor motion sensing with adjustable detection characteristics to suit different room sizes and mounting heights. Typical applications Automated lighting: Turn lights on when a person enters a room and off after a set timeout to save energy and improve convenience. Security and alarm systems: Trigger cameras, sirens, or logging systems when unexpected motion is detected. Occupancy sensing: Integrate into HVAC or ventilation controls to run systems only when a space is occupied. Package contents 10 SR501 HCSR501 adjustable PIR motion sensor modules. Installation notes Mount the sensor with a clear view of the monitored area and avoid pointing directly at heat sources or air vents. Adjust sensitivity and delay while testing the real installation environment to balance responsiveness and falsetrigger suppression. Use appropriate lowvoltage DC supply and interface logic compatible with your control system. This set of 10 modules provides a practical, adjustable solution for adding motion detection to projects and small installations that require reliable, loweffort sensing.