The PIR Motion Sensor Detector Module HC-SR501 allows you to sense motion. It is always used to detect the motion of a human body within the sensor’s range. A passive infrared sensor (PIR sensor) is an electronic sensor that measures infrared (IR) light radiating from objects in its field of view. They are most often used in PIR-based motion detectors. … PIR sensors detect general movement but do not give information on whom or what moved.
The module has an onboard pyroelectric sensor, conditioning circuitry, and a dome-shaped Fresnel lens. It has a delay time adjustment Potentiometer and sensitivity adjustment Potentiometer. Repeat Trigger Selection Jumper is also available. This is Compatible with ARDUINO, RASPBERRY PI, AVR, PIC, 8051, etc.