PIR Motion Detector Sensor Module HC-SR501

PIR Motion Detector Sensor Module HC-SR501 is a highly versatile and cost-effective solution for detecting human presence or movement in a variety of automation and security projects. This module operates by sensing the infrared radiation emitted by moving objects, particularly the human body, through its specialized Fresnel lens. Consequently, it provides a reliable digital output signal that triggers microcontrollers, relays, or alarms whenever it detects a change in the ambient infrared environment. Furthermore, the HC-SR501 features onboard potentiometers that allow users to manually adjust both the sensitivity and the output timing delay. Therefore, you can easily customize the sensor’s behavior to suit specific environmental conditions or project requirements, ensuring peak performance in any DIY or industrial application.

Key Features:

• Adjustable Sensitivity: The onboard potentiometer allows you to modify the detection distance from approximately 3 meters up to 7 meters.
• Variable Time Delay: Users can set the output signal duration from 5 seconds to as long as 300 seconds using the integrated timing adjustment screw.
• Dual Trigger Modes: The module supports both “L” (non-repeatable trigger) and “H” (repeatable trigger) modes via a jumper setting, providing flexibility for different logic requirements.
• Wide Operating Voltage: This sensor operates reliably on a broad DC input range, making it compatible with most standard power supplies and battery packs.
• Low Power Consumption: Its efficient design ensures a minimal current draw in standby mode, which is ideal for battery-powered remote monitoring systems.

Technical Specifications:

• Operating Voltage Range: DC 4.5 V to 20 V
• Static Current: < 50 μA
• Level Output: High 3.3 V / Low 0 V
• Trigger Mode: L (Unrepeatable Trigger) / H (Repeatable Trigger)
• Detection Angle: < 100° cone angle
• Detection Distance: 3 m to 7 m (Adjustable)
• Delay Time: 5 s to 300 s (Adjustable)
• Block Time: 2.5 s (Default)
• Operating Temperature: −15°C to +70°C

Mechanical Specifications:

• Lens Type: High-quality White Fresnel Lens
• Board Material: Dual-layer FR-4 Glass Fiber PCB
• Mounting: Two 2 mm diameter mounting holes for secure installation
• Component Layout: Features two adjustment potentiometers and a 3-pin male header for easy connectivity.

Dimensions:

• PCB Dimensions: 32 mm x 24 mm
• Total Height (including lens): ≈ 25 mm
• Lens Diameter: ≈ 23 mm
• Mounting Hole Distance: 28 mm

Pinout and Wiring:

• VCC (Pin 1): Connect to a positive DC power source (4.5 V to 20 V).
• OUT (Pin 2): Connect this digital output pin to your microcontroller GPIO or a transistor-driven relay.
• GND (Pin 3): Connect to the common ground of your circuit.
• Adjustment Note: Turn the “SENS” potentiometer clockwise to increase distance and the “TIME” potentiometer clockwise to increase the signal duration.

Datasheet Reference:

• Download HC-SR501 PIR Motion Sensor Datasheet

Commonly Used in:

• Security Systems: Serving as the primary detection trigger for intruder alarms and surveillance cameras.
• Smart Lighting: Automating corridor, bathroom, or garage lights to save energy when no movement is present.
• Arduino and Robotics: Enabling robots to interact with humans or avoid obstacles based on thermal detection.

Applications:

• Industrial Automation: Activating machinery or displays only when operators are in close proximity.
• Visitor Counters: Counting foot traffic at entrances when coupled with a simple logging microcontroller.
• Battery-Powered Alarms: Creating portable motion-detecting security devices due to the module’s low idle current.

Equivalent Models:

• AM312: A mini-PIR module that is significantly smaller, however, it offers less manual adjustability compared to the HC-SR501.
• SR602: A compact, fast-response PIR sensor that lacks the physical adjustment potentiometers of the SR501 series.
• HC-SR505: A smaller, automatic version of the HC-SR501 that features a fixed delay and sensitivity for space-critical designs.

Package Includes:

• 1 x PIR Motion Detector Sensor Module HC-SR501