How to Designing a Complete Obstacle-Avoiding Robot?

Global electronic component supplier AMPHEO PTY LTD: Rich inventory for one-stop shopping. Inquire easily, and receive fast, customized solutions and quotes.

We’ll build an ultrasonic sensor-based obstacle-avoiding robot using Arduino. It’s a common, beginner-friendly approach with a balance of simplicity and effectiveness.

📋 1. Components Required:

Electronics:

🧠 Arduino Uno (or compatible microcontroller)
📡 Ultrasonic Sensor (e.g., HC-SR04)
🔌 Motor Driver Module (L298N)
🚗 2 DC Motors with Wheels
🔄 Caster Wheel (for balance)
🔋 Battery Pack (9V or 12V)
📦 Chassis/Body Kit
🪛 Breadboard and Jumper Wires

Optional:

⚡ On/Off Switch
🔊 Buzzer (for sound feedback)
💡 LEDs (for status indication)

🛠️ 2. Circuit Diagram and Connections:

Ultrasonic Sensor (HC-SR04):

VCC: 5V on Arduino
GND: GND on Arduino
Trigger Pin: Digital Pin 9
Echo Pin: Digital Pin 10

Motor Driver (L298N):

IN1 & IN2 (Motor 1): Digital Pin 4, 5
IN3 & IN4 (Motor 2): Digital Pin 6, 7
ENA & ENB: Connect to PWM pins (e.g., 3, 11)
VCC: Battery Positive
GND: Battery Ground & Arduino GND

DC Motors:

Motor 1: Left Wheel
Motor 2: Right Wheel

💻 3. Arduino Code:

Below is a basic example of an obstacle-avoiding robot code:

cpp

// Pin Definitions


const int trigPin = 9;

const int echoPin = 10;

const int motorLeft1 = 4;

const int motorLeft2 = 5;

const int motorRight1 = 6;

const int motorRight2 = 7;

const int motorSpeedLeft = 3;

const int motorSpeedRight = 11;

// Variables


long duration;

float distance;

void setup() {

  Serial.begin(9600);

pinMode(trigPin, OUTPUT);

  pinMode(echoPin, INPUT);

pinMode(motorLeft1, OUTPUT);

  pinMode(motorLeft2, OUTPUT);

pinMode(motorRight1, OUTPUT);

pinMode(motorRight2, OUTPUT);

pinMode(motorSpeedLeft, OUTPUT);

  pinMode(motorSpeedRight, OUTPUT);

float getDistance() {

  digitalWrite(trigPin, LOW);

delayMicroseconds(2);

  digitalWrite(trigPin, HIGH);

  delayMicroseconds(10);

digitalWrite(trigPin, LOW);

duration = pulseIn(echoPin, HIGH);

return duration * 0.034 / 2; // Convert to centimeters

void moveForward() {

analogWrite(motorSpeedLeft, 150);

  analogWrite(motorSpeedRight, 150);

digitalWrite(motorLeft1, HIGH);

digitalWrite(motorLeft2, LOW);

  digitalWrite(motorRight1, HIGH);

  digitalWrite(motorRight2, LOW);

}

void moveBackward() {

  digitalWrite(motorLeft1, LOW);

  digitalWrite(motorLeft2, HIGH);

digitalWrite(motorRight1, LOW);

  digitalWrite(motorRight2, HIGH);

  delay(500);

void turnRight() {

  digitalWrite(motorLeft1, HIGH);

  digitalWrite(motorLeft2, LOW);

digitalWrite(motorRight1, LOW);

digitalWrite(motorRight2, HIGH);

delay(500);

void turnLeft() {

  digitalWrite(motorLeft1, LOW);

digitalWrite(motorLeft2, HIGH);

digitalWrite(motorRight1, HIGH);

digitalWrite(motorRight2, LOW);

delay(500);

void stopMotors() {

digitalWrite(motorLeft1, LOW);

digitalWrite(motorLeft2, LOW);

  digitalWrite(motorRight1, LOW);

digitalWrite(motorRight2, LOW);

void loop() {

distance = getDistance();

  Serial.println(distance);

if (distance < 20) { // Obstacle detected within 20 cm


    stopMotors();

delay(200);

    moveBackward();

delay(500);

    turnRight();

    delay(500);

} else {

    moveForward();

}

🔄 4. Working Principle:

The ultrasonic sensor emits sound waves to detect obstacles.
If an obstacle is detected within 20 cm, the robot:
- Stops
- Moves backward
- Turns (e.g., right)
If no obstacle is detected, the robot continues moving forward.

📊 5. Calibration and Testing:

Upload the code to Arduino.
Power the robot using the battery pack.
Place obstacles in front and observe how it reacts.
Adjust motor speed and distance threshold if needed.

🧠 6. Improvements (Optional):

Add multiple ultrasonic sensors (front, left, and right) for better coverage.
Integrate an IR sensor for closer range detection.
Add a buzzer or LED for alerts.
Use AI or camera-based vision systems for smarter navigation.

Isn't it easy? Have you learned it?

How to Using Arduino Designing a Complete Obstacle-Avoiding Robot?

📋 1. Components Required:

Electronics:

Optional:

🛠️ 2. Circuit Diagram and Connections:

Ultrasonic Sensor (HC-SR04):

Motor Driver (L298N):

DC Motors:

💻 3. Arduino Code:

🔄 4. Working Principle:

📊 5. Calibration and Testing:

🧠 6. Improvements (Optional):

Related Articles