This is a PIR (passive infrared motion) sensor designed to work with Arduino and Raspberry Pi. It allows you to sense motion, it is commonly used to detect whether a human has moved in or out of the sensors range. They are small, inexpensive, low-power, easy to use and don't wear out.
Apr 24, 2018· PIR_Motion_Sensor. Grove - PIR Motion Sensor. This is a simple to use PIR motion sensor with Grove compatible interface. This sensor allows you to sense motion, usually human movement in its range. Simply connect it to Grove - Base shield and program it, when anyone moves in its detecting range, the sensor will output HIGH on its SIG pin.