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. The PIR Sensor is compatible with all Parallax microcontrollers; sample BS1, BS2, and SX/B programs and product documentation are available under Downloads (below).

Features:

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

Parallax Perspective:

Click to Watch Video

Downloads & Resources:
PIR Sensor Documentation v1.2 (.pdf)
Sample Source Code for BS1, BS2, SX/B (.zip)
Scary Terry's PIR Sensor Report (Off Site)
Sensor Objects for Propeller Programmers
Report on the Parallax PIR sensor by Scary Terry