MHSR602 Motion Detector Sensor Module SR602 Human Infrared Detection Sensor Module A compact passive infrared motion detector module designed for reliable human presence sensing and easy integration into electronics projects and automation systems. The module detects moving warm bodies and produces a clean digital output for microcontrollers, relay modules, and alarm inputs. Key benefits Detects human motion to trigger lights, alarms, or control logic without constant manual intervention. Adjustable sensitivity and hold time let you tune detection range and how long the output stays active after motion stops. Simple threewire connection for quick hookup to common microcontroller platforms and external control circuits. Small PCB footprint with Fresnel lens keeps the sensor discreet and easy to mount in tight spaces. Low idle power usage allows battery or lowvoltage power supplies to be used in portable or remote setups. What it does and how it helps Passive infrared sensing senses change in infrared radiation caused by human movement, so the module responds only to motion rather than continuous heat sources. The digital output provides a straightforward signal that can turn on lights, start timers, wake devices from lowpower modes, or feed security systems. Two onboard adjustment controls let you reduce false triggers or extend detection distance and output hold time to match the application environment. Compatibility and connections Designed for easy use with Arduino, Raspberry Pi, ESP series controllers, and other microcontroller boards. Standard signal output suitable for input to digital GPIO pins and relay driver circuits. Simple wiring for power, ground, and signal reduces setup time and integration effort. Physical attributes and performance Compact printed circuit board with Fresnel lens and adjustment potentiometers for sensitivity and time delay. Lightweight and low profile for hidden mounting in enclosures, ceilings, or lamp fixtures. Responsive motion detection with adjustable range and hold time for flexible performance in different rooms and lighting conditions. Typical applications Automatic lighting control in hallways, stairwells, closets, and entryways to reduce manual switching and improve convenience. Basic intrusion or perimeter notification in DIY alarm systems and access control projects. Energysaving controls for office spaces, restrooms, and storage areas where lights and devices only need to run when people are present. Installation tips Mount the sensor with a clear line of sight to the area you want to monitor and avoid direct airflow from vents that may cause false triggers. Start with conservative sensitivity and time settings, then adjust the potentiometers while observing response to actual movement in the intended space. Use common lowvoltage DC power from project supplies and connect the signal output to a digital input with appropriate pullup or pulldown as required by your controller. This module provides a practical, adjustable motion sensing solution for electronics projects, home automation, and basic security applications where a compact and easytouse PIR sensor is needed.