PIR sensor is great for robotics and home automation applications where it required to detect changes in the environment and expecially human motion. Applications include motion detecting alarm systems, motion detecting robot etc. This module has a very low power consumption about 50µA, and so is especially suitable for battery powered products. Two potentiometers on the sensor control the ‘distance sensitivity’ (approximately 3 to 7m) and delay time (approximately 5 to 300s) when a motion is detected. Try to avoid direct light and other interference sources close to modules’ lens, so as not to introduce false action of interference.