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IR Sensor with Arduino UNO

IR Sensor with Arduino UNO
Atribot team

Written by

Atribot team

Last updated

June 18, 2026

Introduction

IR (Infrared) Sensors are widely used in Arduino projects for object detection, obstacle avoidance, line-following robots, and automation systems. These sensors work by emitting infrared light and detecting the reflected signal from nearby objects.

In this tutorial, you will learn how to connect an IR Sensor Module to an Arduino UNO, upload the code, and detect objects using the Serial Monitor. By the end of this guide, you'll understand how IR sensors work and how to use them in your own projects.

Components Required

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Item NameQtyAction
Arduino UNO
1
IR Sensor
1
USB Cable
1
Breadboardit is optional
1
Jumper Wires
3

Tools Required

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Item NameAction
Screwdriver

Software Required

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Item NameAction
Arduio IDEDownload and install the Arduino IDE before proceeding.

Circuit Diagram

IR Sensor with Arduino UNO Circuit Diagram
IR Sensor with Arduino UNO Circuit Diagram

Source Code

IR-Sensor_with_Arduino_UNO.inocpp
const int irSensorPin = 2;

void setup()
{
  pinMode(irSensorPin, INPUT);

  Serial.begin(9600);
}

void loop()
{
  int sensorState = digitalRead(irSensorPin);

  if(sensorState == LOW)
  {
    Serial.println("Object Detected");
  }
  else
  {
    Serial.println("No Object");
  }

  delay(500);
}

Step by Step Instructions

Step 1: Connect the IR Sensor to Arduino

Make the following connections:

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IR Sensor

Arduino UNO

VCC

5V

GND

GND

OUT

Digital Pin 2

Step 2: Open Arduino IDE

  1. Launch Arduino IDE.

  2. Connect Arduino UNO using USB.

  3. Select:

    • Board → Arduino UNO

    • Port → Correct COM Port

Step 3: Write the Program

Create a new sketch and paste the code below.

Step 4: Upload the Code

  1. Click Verify.

  2. Click Upload.

  3. Wait for "Done Uploading."

Step 5: Open Serial Monitor

  1. Open Serial Monitor.

  2. Set baud rate to 9600.

  3. Move an object in front of the sensor.

You should see detection messages.