Grove - Mini PIR motion sensor

The Grove - Mini PIR motion sensor is a compact, low power and cost effective PIR sensor which is suitable for applications with relatively less detection distance requirements.

The detection distance in the datasheet is up to 3m to 5m, however 2m is the best detection distance that we recommend and 25℃ is the most suitable temperature. The sensitivity of the sensor is adjustable, there is a reserved pin out on the back of the board so that you can solder a slide rheostat to adjust the sensitivity. If you think the sensitivity is not enough, here is a trick, drag the plastic cap a little up will help enhance the sensitivity.

What is a PIR Sensor?

A passive infrared sensor is an electronic sensor that measures infrared light radiating from objects in its field of view. They are most often used in PIR-based motion detectors. PIR sensors are commonly used in security alarms and automatic lighting applications.

What does a PIR sensor detect?

PIR sensors are also known as PID or Passive Infrared Detectors. Thus, the PIR sensor can detect infrared radiation that is emitted by particles.

How does PIR Sensor work?

The PIR Sensor has 2 slots, and the slots are made of sensitive material. When the sensor is inactive, then the two slots will sense the same amount of IR. The ambient amount radiates from the outdoors, walls or room, etc.
When a human body or any animal passes by, it intercepts the first slot of the PIR sensor. This causes a positive differential change between the two bisects. But when the body leaves the sensing area, the sensor generates a negative differential change between the two bisects.

Specifications

• Sensor chip: S16-L221D
• Supply Voltage: 2.7 – 3.3V
• Working Current: 12 – 20 μA
• Sensitivity: 120 – 530 μV
• Max detecting range: 2m (25℃)