Arduino Technology
John Park in the Maker Shed: PIR Arduino motion alarm

Want to learn how to hook up a passive infrared (PIR) sensor to your Arduino? Check out this video I put together doing just that. These sensors are very nice to work with either by themselves (along with a transistor or relay) or on a microcontroller. You get about a 20 ft. range for detecting motion from humans, animals, other things that emit a decent amount of infrared radiation. WILL NOT DETECT THE UNDEAD.

This is the same alarm setup I used to prank my kids on April Fools’ Day.

In the Maker Shed:

The PIR Sensor detects motion up to 20 feet away by using a Fresnel lens and infrared-sensitive element to detect changing patterns of passive infrared emitted by objects in its vicinity. Inexpensive and easy to use, it’s ideal for alarm systems, motion-activated lighting, holiday props, and robotics applications.


  • Simple 3-pin connection
  • Single bit output
  • Small size – easy to conceal ( 0.96 x 1.0 x 1.27 in.)
  • Arduino Compatible


PIR Sensor


John Edgar Park likes to make things and tell people about it. He builds project for Adafruit Industries. You can find him at and twitter/IG @johnedgarpark

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