Introduction

This experiment demonstrates how to use a PIR motion sensor with an Arduino to create a simple security system that detects motion.

Components Needed

• PIR Motion Sensor
• Arduino (e.g., Uno, Nano)
• LED
• 220-ohm Resistor
• Jumper wires

No Ads Available.

Circuit Setup

1. Connect the PIR sensor's output to a digital input pin (e.g., D2) on the Arduino.
2. Connect the LED to a digital output pin using a 220-ohm resistor in series.

The LED will light up when motion is detected.

Code for PIR Motion Sensor

Upload the following code to your Arduino to detect motion:

const int pirPin = 2;
const int ledPin = 13;

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

void loop() {
  int sensorValue = digitalRead(pirPin);
  if (sensorValue == HIGH) {
    digitalWrite(ledPin, HIGH);  // Turn on LED when motion is detected
    Serial.println("Motion Detected!");
  } else {
    digitalWrite(ledPin, LOW);   // Turn off LED when no motion
    Serial.println("No Motion");
  }
  delay(500);
}
            

Explanation

The PIR motion sensor detects motion and sends a HIGH signal to the Arduino. This triggers the LED to light up, and a message is printed on the Serial Monitor.

Troubleshooting

• If the sensor doesn't detect motion, check the wiring and ensure the sensor is powered correctly.
• If the LED remains on or off, verify the sensor's sensitivity setting.