Passive InfraRed (PIR) Motion Sensor Detector Module HC-SR501

The PIR Motion Sensor Detector Module HC-SR501 is a highly reliable infrared motion detection sensor designed to detect human movement by sensing changes in infrared radiation emitted from warm bodies. 🚶‍♂️🔥 This module is widely used in security systems, automatic lighting, motion-activated alarms, smart home automation, and DIY electronics projects.

Powered by the HC-SR501 PIR sensor, this module offers stable detection performance, low power consumption, and easy interfacing. It features adjustable sensitivity (detection range) and adjustable delay time, allowing users to customize detection distance and output trigger duration as per their application needs.

The module provides a digital output signal that goes HIGH when motion is detected and LOW when no movement is present, making it perfect for triggering relays, lights, buzzers, cameras, or microcontroller-based systems. ⚡ With its compact design and onboard Fresnel lens, it ensures accurate and wide-angle motion coverage.

Key Features:

✔ Accurate human motion detection using PIR technology
✔ Adjustable sensitivity and output delay time
✔ Wide detection angle with Fresnel lens
✔ Low power consumption for continuous operation
✔ Easy digital output interface

HC-SR501 PIR Motion Sensor – Pinout Details

Power Pins

• VCC (+5V):
  Power supply input pin. Supports 4.5V to 20V DC. Commonly powered using 5V DC for stable and safe operation in DIY, automation, and security projects. ⚡

• GND (Ground):
  Ground pin for power and signal reference. Must be connected to the common ground of the system or controller for accurate motion detection and noise-free output.

Signal Pin

• OUT (Digital Output):
  Digital output pin that goes HIGH (≈3.3V) when motion is detected and LOW (0V) when no movement is present. This pin can directly trigger relay modules, buzzers, lights, alarms, or microcontrollers such as Arduino-compatible boards.

⚙️ Onboard Controls (Not Pins but Important)

• Sensitivity Adjustment Potentiometer:
  Adjusts the motion detection range, typically up to 7 meters, allowing fine tuning for small rooms or large open areas.

• Time Delay Adjustment Potentiometer:
  Controls how long the OUT pin remains HIGH after motion is detected, adjustable from a few seconds to several minutes.

• Trigger Mode Jumper:

  • H (Repeatable Trigger): Output stays HIGH as long as motion continues

  • L (Non-Repeatable Trigger): Output goes HIGH once per detection cycle

⚠️ Important Usage Notes

• Allow 30–60 seconds warm-up time after powering the module for stable operation.

• Avoid facing the sensor directly toward sunlight, heaters, or moving heat sources to reduce false triggers.

• OUT pin is digital only, no analog signal available.

• Best performance achieved when mounted 1.8–2.5 meters height.