Arduino Obstacle Avoiding Robot in Ayantrik Lab

TL;DR: In this project, we build an Obstacle Avoiding Robot using Arduino, ultrasonic sensor, servo motor, motor driver, and DC motors in Ayantrik Lab. The robot detects obstacles in front of it, scans surroundings, and automatically chooses a safe direction to move.

The Problem / Why This Matters

In real-world robotics, avoiding obstacles is one of the most important challenges.

Obstacle avoiding robots are used in:

Self-driving vehicles
Delivery robots
Vacuum cleaning robots
Industrial automation
Surveillance systems

To build intelligent robots, we need:

Sensors to detect environment
Logic to make decisions
Motors to act on those decisions

This project demonstrates how a robot can sense, think, and act autonomously.

Try it here

Basic Concept

This robot uses:

Ultrasonic Sensor → Measures distance
Servo Motor → Rotates sensor to scan left/right
Arduino → Decision making
Motor Driver (L298N) → Controls motors
DC Motors → Move the robot

How It Works (Simple Idea)

Robot moves forward
Detects obstacle using ultrasonic sensor
Stops and scans surroundings
Chooses best direction
Moves in that direction

This creates an intelligent navigation system.

Prerequisites

Components used in this project:

Arduino Uno
Ultrasonic Sensor (HC-SR04)
Servo Motor
L298N Motor Driver
2 DC Motors

All components are available in Ayantrik Lab component library.

Steps to Create the Project in Ayantrik Lab

1. Open a New Project

Open Ayantrik Lab and create a new project.

Create New Project

2. Add Components

Toolbar Toolbar

Click Add Components and add:

Arduino Uno
Ultrasonic Sensor
Servo Motor
L298N Motor Driver
2 DC Motors

Arrange them properly.

3. Make the Circuit Connections

Connection Connection

Ultrasonic Sensor → Arduino

TRIG → D12
ECHO → D11
VCC → 5V
GND → GND

Servo Motor → Arduino

Signal → D10
VCC → 5V
GND → GND

Arduino → Motor Driver

D8 → IN1
D7 → IN2
D6 → IN3
D5 → IN4
D9 → ENA
D4 → ENB

Motor Driver → Motors

OUT1 & OUT2 → Left Motor
OUT3 & OUT4 → Right Motor

Power Connections

Motor Driver → GND
All components share common GND

Code

Upload the following Arduino code:


c
#include <Servo.h>

// Motor A
const int enA = 9; 
const int in1 = 8; 
const int in2 = 7;

// Motor B
const int enB = 4; 
const int in3 = 6; 
const int in4 = 5;

// Ultrasonic
const int trigPin = 12;
const int echoPin = 11;

// Servo
Servo radarServo;
const int servoPin = 10;

const int safetyDistance = 25;

// Distance function
int getDistance() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  long duration = pulseIn(echoPin, HIGH);
  return duration * 0.034 / 2;
}

void moveForward() {
  digitalWrite(in1, HIGH); digitalWrite(in2, LOW);
  digitalWrite(in3, HIGH); digitalWrite(in4, LOW);
  analogWrite(enA, 160); analogWrite(enB, 160);
}

void moveStop() {
  digitalWrite(in1, LOW); digitalWrite(in2, LOW);
  digitalWrite(in3, LOW); digitalWrite(in4, LOW);
}

void moveBackward() {
  digitalWrite(in1, LOW); digitalWrite(in2, HIGH);
  digitalWrite(in3, LOW); digitalWrite(in4, HIGH);
  delay(400);
}

void turnRight() {
  digitalWrite(in1, HIGH); digitalWrite(in2, LOW);
  digitalWrite(in3, LOW); digitalWrite(in4, HIGH);
  delay(500);
}

void turnLeft() {
  digitalWrite(in1, LOW); digitalWrite(in2, HIGH);
  digitalWrite(in3, HIGH); digitalWrite(in4, LOW);
  delay(500);
}

int lookRight() {
  radarServo.write(10);
  delay(500);
  int d = getDistance();
  radarServo.write(90);
  return d;
}

int lookLeft() {
  radarServo.write(170);
  delay(500);
  int d = getDistance();
  radarServo.write(90);
  return d;
}

void setup() {
  pinMode(enA, OUTPUT); pinMode(in1, OUTPUT); pinMode(in2, OUTPUT);
  pinMode(enB, OUTPUT); pinMode(in3, OUTPUT); pinMode(in4, OUTPUT);
  pinMode(trigPin, OUTPUT); pinMode(echoPin, INPUT);

  radarServo.attach(servoPin);
  radarServo.write(90);
}

void loop() {
  int distanceAhead = getDistance();

  if (distanceAhead <= safetyDistance) {
    moveStop();
    moveBackward();

    int right = lookRight();
    int left = lookLeft();

    if (right >= left) {
      turnRight();
    } else {
      turnLeft();
    }
  } else {
    moveForward();
  }
}

How the Logic Works

The robot continuously checks the distance in front using the ultrasonic sensor and makes decisions based on that.

Step 1: Move Forward

Robot moves forward normally
Continuously measures distance ahead

Step 2: Detect Obstacle

If distance ≤ safety distance (e.g., 25 cm)

Meaning:

An obstacle is detected in front

Action:

Robot stops immediately

Step 3: Move Backward

Robot moves slightly backward

Purpose:

Create space to make a turn

Step 4: Scan Right Side

Servo rotates sensor to the right
Measures distance

Step 5: Scan Left Side

Servo rotates sensor to the left
Measures distance

Step 6: Compare Distances

Compare left and right distances

Decision:

If right side is clearer → turn RIGHT
Else → turn LEFT

Step 7: Turn and Continue

Robot turns in selected direction
Resumes forward movement

Expected Behavior

When you run the simulation:

Robot moves forward
Detects obstacles automatically
Stops before collision
Scans both sides
Chooses the safest direction
Continues moving

Built-in Debugging in Ayantrik Lab

Ayantrik Lab provides a built-in debugging system.

It helps detect:

Incorrect wiring
Missing power connections
Wrong pin mapping
Code errors

Debugging Debugging

This makes learning robotics easier for beginners.

Conclusion

In this project, we built an Obstacle Avoiding Robot using Arduino in Ayantrik Lab.

You learned:

Distance measurement using ultrasonic sensor
Servo-based scanning mechanism
Autonomous decision making
Motor control using driver module

This is a foundational project for intelligent robotics systems.

Next Steps

Try extending this project:

Add obstacle memory (path optimization)
Integrate Bluetooth or WiFi control
Add multiple sensors for better accuracy
Build a fully autonomous navigation robot

Happy learning with Ayantrik Lab.!

How to build an Obstacle Avoiding Robot in Ayantrik Lab