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HCSR501 PIR Motion Sensor (Passive Infrared Sensor)

HCSR501 PIR Motion Sensor (Passive Infrared Sensor)

β‚Ή61.00Price

πŸ‘οΈβ€πŸ—¨οΈ HC-SR501 PIR Motion Sensor

Human Motion Detection β€’ Low Power β€’ Smart Automation

The HC-SR501 PIR Motion Sensor Module is a widely used Passive Infrared (PIR) sensor designed to detect motion from humans or animals by sensing changes in infrared radiation. It is commonly used in security systems, automatic lighting, robotics, and IoT projects.

The module includes a pyroelectric infrared sensor and Fresnel lens that helps detect movement within its detection range.

πŸ“Š Infographic Overview

πŸ”Ή Basic Specifications

FeatureDetails
πŸ”Œ Operating Voltage5V – 20V DC
⚑ Operating Current~50 ¡A (very low power)
πŸ“‘ Output TypeDigital (High/Low)
πŸ“ Detection Range3 – 7 meters
πŸ“ Detection Angle~120Β°
⏱ Delay TimeAdjustable (3s – 5 min)
🌑 Operating Temperature-15°C to +70°C

🧩 Main Components (Based on the Image)

The module typically contains:

πŸ”Ή Fresnel Lens Dome – focuses infrared signals
πŸ”Ή PIR Sensor Element – detects infrared radiation changes
πŸ”Ή BISS0001 Controller IC – signal processing chip
πŸ”Ή Sensitivity Adjustment Potentiometer
πŸ”Ή Delay Time Adjustment Potentiometer
πŸ”Ή Voltage regulator & capacitors

πŸ”Œ Pin Configuration

PinFunction
VCCPower supply (5–20V)
OUTDigital output signal
GNDGround

βš™οΈ Working Principle

The PIR sensor detects infrared radiation emitted by warm objects like humans.

Step-by-Step Operation

1️⃣ The Fresnel lens focuses infrared radiation onto the sensor.
2️⃣ The PIR element detects changes in heat energy.
3️⃣ When a human or animal moves, IR levels change.
4️⃣ The controller IC processes the signal.
5️⃣ The module outputs HIGH signal when motion is detected.

πŸ“ Sensor Layout (Simplified)

HC-SR501 PIR Motion Sensor

β”Œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”
β”‚ Fresnel Lens β”‚
β”‚ (Motion Detection)β”‚
β””β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”˜
β”‚
β”Œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”
β”‚ PIR Sensor Chip β”‚
β”‚ Signal Processor β”‚
β””β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”˜

Adjustments
β”Œβ”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”
β”‚ Sensitivity β”‚
β”‚ Delay Time β”‚
β””β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”€β”˜

Pins
β”Œβ”€β”€β”€β”€β”€β”¬β”€β”€β”€β”€β”€β”¬β”€β”€β”€β”€β”€β”
β”‚VCC β”‚OUT β”‚GND β”‚
β””β”€β”€β”€β”€β”€β”΄β”€β”€β”€β”€β”€β”΄β”€β”€β”€β”€β”€β”˜

πŸŽ› Adjustable Settings

The HC-SR501 has two adjustable potentiometers:

πŸ”§ Sensitivity Adjustment

  • Controls motion detection distance

⏱ Delay Time Adjustment

  • Controls how long the output stays HIGH after motion detection

πŸ€– Common Applications

🏠 Home security systems
πŸ’‘ Automatic lighting systems
πŸšͺ Smart door automation
πŸ€– Robotics motion detection
πŸ“· Security camera triggering
🌐 IoT smart home devices

πŸ”Œ Compatible Microcontrollers

The PIR sensor can easily connect to popular development boards:

  • Arduino Uno

  • ESP32

  • Arduino Nano

  • Raspberry Pi

πŸ’‘ Advantages

βœ… Very low power consumption
βœ… Wide detection angle (~120Β°)
βœ… Adjustable sensitivity and delay
βœ… Easy digital output interface
βœ… Ideal for motion detection systems

⚠️ Limitations

❌ Cannot detect stationary objects
❌ Sensitive to temperature changes
❌ False triggers possible from pets or heat sources

πŸ”§ Example Project Idea

πŸ’‘ Automatic Motion-Activated Light

Components

  • PIR Motion Sensor (HC-SR501)

  • Arduino Uno

  • Relay module

  • LED light or bulb

Working

βœ” Sensor detects human motion
βœ” Microcontroller activates relay
βœ” Light turns ON automatically
βœ” Light turns OFF after delay

Quantity
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