IR sensor for obstacle detection in Arduino - Mini Project: Build & Apply

IR Sensor for Obstacle Detection

📖 Scenario: You are building a simple robot that can detect obstacles using an IR sensor. The sensor will tell the robot if something is close by, so it can stop or change direction.

🎯 Goal: Create a program that reads the IR sensor value and prints Obstacle detected when an obstacle is close, or No obstacle when the path is clear.

📋 What You'll Learn

Use a variable called irSensorPin to store the IR sensor input pin number.

Use a variable called threshold to set the distance limit for obstacle detection.

Read the sensor value using digitalRead(irSensorPin).

Use an if statement to check if the sensor detects an obstacle.

Print Obstacle detected or No obstacle accordingly.

💡 Why This Matters

🌍 Real World

IR sensors are used in robots and devices to detect objects and avoid collisions.

💼 Career

Understanding sensor input and conditional logic is important for embedded systems and robotics jobs.

1

Set up the IR sensor pin

Create a variable called irSensorPin and set it to 7. Then set the pin mode of irSensorPin to INPUT inside the setup() function.

Arduino

int irSensorPin = 7;

void setup() {
  // Set irSensorPin as input
  // Your code here
}

void loop() {
  // Your code here
}

Hint

Use pinMode(irSensorPin, INPUT); inside setup() to prepare the sensor pin.

2

Add a threshold variable

Create a variable called threshold and set it to 1. This will be used to decide if an obstacle is detected.

Arduino

int irSensorPin = 7;
int threshold = 1;  // Your code here

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

void loop() {
  
}

Hint

The threshold variable helps decide when the sensor detects an obstacle.

3

Read sensor and check for obstacle

Inside the loop() function, read the sensor value into a variable called sensorValue using digitalRead(irSensorPin). Then use an if statement to check if sensorValue equals threshold.

Arduino

int irSensorPin = 7;
int threshold = 1;

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

void loop() {
  int sensorValue = digitalRead(irSensorPin);  // Your code here
  if (sensorValue == threshold) {
    // Your code here
  }
}

Hint

Use digitalRead(irSensorPin) to get the sensor value and compare it with threshold.

4

Print obstacle detection result

Inside the if block, print Obstacle detected using Serial.println(). Add an else block to print No obstacle when the sensor value does not equal threshold.

Arduino

int irSensorPin = 7;
int threshold = 1;

void setup() {
  pinMode(irSensorPin, INPUT);
  Serial.begin(9600);
}

void loop() {
  int sensorValue = digitalRead(irSensorPin);
  if (sensorValue == threshold) {
    // Your code here
  } else {
    // Your code here
  }
}

Hint

Use Serial.println() to show messages on the serial monitor. Add a small delay to avoid flooding the output.