HC-SR505 Pir Motion Sensor Module

Compact PIR motion sensor module for detecting human movement in automation and alarm systems. The HC-SR505 is a miniature passive infrared (PIR) motion sensor that detects moving heat sources, like humans or animals, by measuring changes in infrared radiation. Operating on 4.5V to 20V, it features a simple three-pin interface: power (VCC), ground (GND), and a digital output. When motion is detected within its 3-meter range, the output pin flips to a high state (3.3V) for a fixed delay of roughly 8 seconds before returning to low (0V), making it highly efficient for compact security, automation, and battery-powered applications.