PIR Motion Sensor Arduino Project

Author: Aus Electronics Direct   Date Posted:9 April 2019 

PIR Motion Sensor Arduino Project

This tutorial demonstrates how to detect motion from PIR Sensor using Arduino Uno Development Board. When the PIR detects, it will trigger the LED to light up showing as the output.

Electric Parts Required


Please follow the schematic below to setup this project.






PIR Motion Sensor with Arudino Demo Code




int led = 13;                // Define the LED as Pin 13

int sensor = 4;              // Define the Sensor Connected to Pin 4

int state = LOW;             // Motion Detection

int val = 0;                 // Store the value of sensor


void setup() {

  pinMode(led, OUTPUT);      // initialize the LED as the output

  pinMode(sensor, INPUT);    // initialize the sensor as the input

  Serial.begin(9600);        // Define the serial communication



void loop(){

  val = digitalRead(sensor);   // Reading the sensor value

  if (val == HIGH) {           // if sensor is high

    digitalWrite(led, HIGH);   // switch on the LED

    delay(100);                // 100 milliseconds delay


    if (state == LOW) {

      Serial.println("Motion was detected");

      state = HIGH;       // Update the variable state in to HIGH



  else {

      digitalWrite(led, LOW); // Turning off the LED

      delay(200);             // 200 milliseconds delay


      if (state == HIGH){

        Serial.println("Motion stopped!");

        state = LOW;       // update the variable state into LOW





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