PIR Motion Sensor

Detect motion and enhance automation with PIR sensors.

Introduction

A Passive Infrared (PIR) Motion Sensor is a compact and reliable device used to detect motion in its surrounding environment. It senses infrared radiation emitted by objects, particularly humans or animals, making it ideal for security systems, automation, and smart homes.

Pinout

The PIR motion sensor module typically has three pins:

Pin	Name	Description
1	VCC	Connects to the power supply, typically 5V or 3.3V.
2	OUT	Outputs a digital signal (HIGH when motion is detected, LOW otherwise).
3	GND	Ground connection for completing the circuit.

Working Principle

The PIR motion sensor detects infrared radiation from moving objects:

The sensor is equipped with a pyroelectric material that detects infrared radiation.
When a warm object (e.g., a human) moves within its range, the infrared radiation levels change.
This change is converted into an electrical signal and processed to indicate motion.
The output pin goes HIGH when motion is detected and LOW otherwise.

Features

Key features of the PIR Motion Sensor include:

Low power consumption for extended battery life.
Adjustable sensitivity and delay time for customization.
Wide detection angle (usually 110° to 120°).
Compact and lightweight design for easy integration.
Digital output for direct use with microcontrollers.

Applications

PIR motion sensors are used in:

Home automation systems (e.g., automatic lights).
Security alarms and surveillance systems.
Energy-saving devices like automated HVAC systems.
Smart appliances and IoT applications.
Motion-activated outdoor lighting.

Troubleshooting

Common issues and their solutions:

No motion detected: Ensure proper power supply and check the sensor's positioning and range.
False triggers: Adjust sensitivity or ensure there are no heat sources near the sensor.
Interference: Avoid placing the sensor near devices emitting strong electromagnetic waves.