The HC-SR501 PIR (Passive Infrared) Motion Sensor Module is an economical, highly sensitive body movement detector widely used in burglar alarms, motion-activated lighting, and home automation systems. The module houses a dual-element pyroelectric sensor underneath a protective white Fresnel lens. The lens splits the surrounding room into multiple detection zones, focusing infrared radiation emitted by warm bodies (at ~9.4 µm wavelength) onto the sensor.

When a human or animal moves across these zones, the differential IR readings trigger the onboard BISS0001 controller chip, outputting a 3.3V HIGH signal on the OUT pin. The board features two multi-turn potentiometers for independent adjustment of sensitivity (distance) and delay time, along with a yellow mode-selection jumper for switching between Repeatable (H) and Non-Repeatable (L) trigger behaviors.

Technical Specifications

Pinout & Control Layout

Basic Arduino Wiring & Example Code

Wiring Diagram

• VCC ➔ Arduino 5V

• GND ➔ Arduino GND

• OUT ➔ Arduino Digital Pin 2

// HC-SR501 PIR Motion Sensor Interfacing
const int pirSensorPin = 2; // OUT pin connected to Digital Pin 2
const int ledPin       = 13;// Onboard Arduino LED

void setup() {
  pinMode(pirSensorPin, INPUT);
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);
  Serial.println("HC-SR501 PIR Motion Sensor Initializing...");
  delay(10000); // 10-second warm-up time for PIR stabilization
  Serial.println("PIR Sensor Active!");
}

void loop() {
  int pirState = digitalRead(pirSensorPin);

  if (pirState == HIGH) {
    digitalWrite(ledPin, HIGH); // Turn ON LED
    Serial.println("MOTION DETECTED! Subject present.");
  } else {
    digitalWrite(ledPin, LOW);  // Turn OFF LED
    Serial.println("Area Clear. Monitoring...");
  }

  delay(500);
}

Key Features & Highlights

• Wide Supply Voltage Range: Works reliably across 4.5V to 20V DC rails, outputting a safe 3.3V TTL signal compatible with both 3.3V and 5V microcontrollers.

• Dual Adjustment Controls: Fine-tune both sensing distance (3m–7m) and output holding time (5s–200s) directly via onboard potentiometers.

• Repeatable vs Non-Repeatable Modes: Configurable jumper lets you choose whether output stays active continuously during ongoing human presence or resets after fixed intervals.

• Ultra-Low Power Idle Consumption: Draws under 50µA at idle, making it well-suited for battery-powered IoT security nodes and solar installations.

Common Applications

• Automatic motion-activated corridor and staircase lighting switches.

• Intrusion detection systems, burglar alarms, and CCTV camera trigger units.

• Energy-saving smart home devices and automated HVAC room occupancy sensors.

• Interactive Halloween props, robotics, and visitor greeting chimes.

What’s Included in the Box

• 1 × HC-SR501 PIR Motion Sensor Module (with Fresnel Lens attached)

Why Buy From Aryabot?

• 100% Verified Hardware: Assembled using authentic BISS0001 ICs, stable pyroelectric sensors, and clean FR-4 glass-fiber PCB fabrication.

• Tested & Benchmarked: Pre-tested for motion sensitivity response, potentiometer delay calibration, and trigger mode functionality.

• GST Invoice Provided: Tax-compliant B2B invoices generated for commercial deployments, educational institutions, and research labs.

• Pan-India Express Dispatch: Fast order processing and direct delivery from our Noida fulfillment warehouse.