Project Hub /Security Surveillance & Defense/Intrusion Detection Systems/How to Interface HC-SR501 PIR (Motion) Sensor with an Arduino

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₹500 – ₹1,500

3 – 6 Hours

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How to Interface HC-SR501 PIR (Motion) Sensor with an Arduino

Learn how to connect and program an HC-SR501 Passive Infrared (PIR) motion sensor with an Arduino Uno to detect human or animal movement.

Originally published on CircuitDigest

View original tutorial

Parts You'll Need

This project is sourced from another site, not written by us — this list is our best match of their components against what we stock, not a verified bill of materials. Always check the original blog (linked above) for the actual parts list before buying.

Arduino UNO R3 Board (Compatible) – ATmega328P Microcontroller with USB Cable Rs. 999.00
PIR Motion Detector Sensor Module HC-SR501 Rs. 153.00
Jumper Wire 10 Pin Male To Male 20cm Rs. 45.00
400 Points Mini Solderless Prototype PCB Breadboard High Quality Rs. 89.00
MB102 Adjustable Breadboard Power Supply Module (3.3V & 5V) for Arduino & Raspberry Pi Rs. 139.00
Jumper Wire 10 Pin Male To Female 20cm Rs. 45.00

Selected: Rs. 0.00

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How It Works

The HC-SR501 Passive Infrared (PIR) motion sensor detects movement by measuring changes in infrared radiation levels emitted by nearby warm objects, such as humans or animals. When a living body enters its field of view, the dual-element sensor registers a differential change in ambient thermal energy and generates a high-level digital logic signal on its output pin. Using jumper wires, this output pin is connected to a digital input pin on the Arduino Uno. The Arduino Uno, running code written in the Arduino IDE, continuously monitors this digital pin. When the Arduino detects the transition from a low state to a high state triggered by the HC-SR501, it interprets this event as detected motion. This simple interface allows the microcontroller to serve as the processing brain for automated trigger logic, which can then be adapted to drive external indicators, log events, or execute further control routines based on real-time environmental occupancy.

Why Build This

Design foundational undergraduate-level intrusion detection and perimeter surveillance prototypes.

Implement automated occupancy-based energy management systems for smart buildings.

Prototype low-cost automated lighting and environmental activation control systems.

Real-World Application

Home security systems, automated lighting control, and occupancy-based power-saving appliances.

Skills You'll Learn

digital sensor interfacing

GPIO signal reading

conditional logic programming

microcontroller input configuration

Safety Precautions

No specific precautions noted for this build — always follow general electronics safety practices.

Technology Tags

PIR SENSOR

HC-SR501

ARDUINO

MOTION DETECTION

INFRARED

SENSORS

Frequently Asked Questions

What power supply does the HC-SR501 PIR sensor require?

The HC-SR501 typically operates on a DC voltage supply between 5V and 20V, which can be conveniently supplied directly from the 5V output pin of the Arduino Uno.

Can this sensor detect stationary people?

No, PIR sensors detect motion by measuring changes in infrared radiation; if a person remains completely still, the sensor will eventually reset to a low output state.

How do I adjust the sensitivity and time delay on the sensor?

The HC-SR501 board features two onboard potentiometers (trimpots) that allow you to manually adjust the detection range and the length of time the output signal remains high after motion is detected.

Gallery

This page is part of Kitkraft's Project Hub — a curated collection of electronics & robotics projects gathered from the maker community to help students and hobbyists discover and learn to build. Kitkraft does not claim authorship of the original project, and makes no representation as to the accuracy, completeness or safety of third-party source material. The summary and "How It Works" explanation above are AI-generated, rewritten with reference to the original tutorial — not a reproduction of it. Full credit and a direct link to the original source are provided above. If you're the original creator and have a concern about how your work is represented here, please contact us and we'll address it promptly.

Kitkraft Project Hub — curated from the maker community, credited at the source.

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