PIR is a human body infrared unit. It belongs to the "passive pyroelectric infrared detector". It detects the infrared radiation emitted and reflected by the human body or object. When infrared is detected, the output level is high and it takes a while. Delay (high during the period and allow repeated triggers) until the trigger signal disappears (restores low).
This Unit communicates with the M5Core via the GROVE B.
Notice: This Unit has 2s delay time.