PIR Motion Sensor HC-SR501

The HC-SR501 PIR Motion Sensor is one of the most widely used motion detection modules in electronics and DIY automation projects. It's super easy to use and works great with Arduino, Raspberry Pi, ESP32, and other microcontrollers.

How It Works:

The sensor detects infrared (IR) radiation changes in its field of view. When a warm object (like a human or pet) moves, the sensor triggers a HIGH signal on its output pin.

Key Features & Specs:

Operating Voltage 5V – 20V DC

Output Voltage 3.3V (HIGH), 0V (LOW)

Detection Range 3 – 7 meters (adjustable)

Detection Angle 120 degrees

Delay Time Adjustable (approx. 5s – 300s)

Trigger Modes Repeatable (default) & Non-repeatable

Board Size 32mm x 24mm

Pinout:

• VCC → Power supply (5V recommended)
• OUT → Digital output (HIGH when motion detected)
• GND → Ground

Adjustable Settings:

1. Sensitivity (distance) – Adjust using the left potentiometer
2. Delay time – Adjust using the right potentiometer
3. Trigger mode jumper:

• H (Repeatable): Resets timer if motion continues.
• L (Non-repeatable): Waits for delay time even if more motion happens.

Sample Arduino Code:

int pirPin = 2;     // Connect OUT pin here
int ledPin = 13;

void setup() {
  pinMode(pirPin, INPUT);
  pinMode(ledPin, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  if (digitalRead(pirPin) == HIGH) {
    digitalWrite(ledPin, HIGH);
    Serial.println("Motion Detected!");
  } else {
    digitalWrite(ledPin, LOW);
  }
  delay(100);
}

Origin: China

Brand: Generic