PIR Motion Sensor Module (SR501)

Description

DESCRIPTIONPIR "Passive Infrared"sensors allow you to sense motion, almost always used to detect whether a human has moved in or out of the sensors rangeHow to Use PIR SensorThe PIR sensor have 3 pins:Power: 3-5 VDCOutput: High (when motion detected) Low (no motion detected)Ground: connected to groundThe output pin will go "high" to 3.3V and light up the LED when motion detected.Specifications:Input Voltage: DC 3-5VOutput signal: 3.3V (motion detected-output high)Detection Angle: 110 degreeDetection Angle: max 7 mHow Does The PIR Sensor WorkThe PIR sensor itself has two slots each one of them is made of a special material that is sensitive to infrared. When a warm body like a human or animal passes by, it first intercepts one half of the PIR sensor. This causes a positive differential change between the two halfes. These change pulses are what is detected.