PIR sensors are used to detect motion from pets/humanoids from about 5 meters away (possibly works on zombies, not guaranteed). This sensor is much smaller than most PIR modules, which makes it great for unobtrusive projects. It's also fully-contained - only needs power and ground, and it's breadboard or perfboard friendly. Usage is super simple: You can power it from 3 to 12V DC, there's an onboard regulator. Digital signal output is 3.3V high/low. The signal goes high when motion is detected, and stays high for another 2 seconds, so you have plenty of time to read the value. Connect pin #1 to ground (there's a tiny minus - sign next to the pin) Connect pin #2 to output signal (there's a tiny O next to this pin that goes high and low) Connect pin #3 to power (there's a tiny plus + sign next to the pin) See more

Connect pin #3 to power (there's a tiny plus + sign next to the pin). Connect pin #2 to output signal (there's a tiny O next to this pin that goes high and low). Connect pin #1 to ground (there's a tiny minus - sign next to the pin). Usage is super simple: You can power it from 3 to 12V DC, there's an onboard regulator. Digital signal output is 3.3V high/low. The signal goes high when motion is detected, and stays high for another 2 seconds, so you have plenty of time to read the value. PIR sensors are used to detect motion from pets/humanoids from about 5 meters away (possibly works on zombies, not guaranteed). This sensor is much smaller than most PIR modules, which makes it great for unobtrusive projects. It's also fully-contained - only needs power and ground, and it's breadboard or perfboard friendly.