Published July 17, 2026

QRcode Following Robot

A vision-guided robot that reads QR codes, decides routes in real time, and autonomously navigates with Raspberry Pi and Arduino.

BeginnerShowcase (no instructions)5 hours61

Things used in this project

Hardware components

Webcam, Logitech® HD Pro

Arduino Nano R3

Raspberry Pi 3 Model B

SparkFun Electronics Dual H-Bridge motor drivers L298

9V battery (generic)

DFRobot DC Geared with Mecanum Wheel

Software apps and online services

Arduino IDE

Microsoft VS Code

Story

Introduction

Autonomous mobile robots are becoming essential in modern industries, warehouses, hospitals, and smart buildings. While advanced navigation technologies such as LiDAR and SLAM offer excellent performance, they are often expensive and computationally intensive, making them impractical for educational projects and small-scale automation.

QR Code Follower Robot demonstrates a simpler yet powerful alternative. By placing QR codes along a predefined route, the robot can identify its location, interpret navigation commands, and move autonomously without requiring complex environmental mapping.

The project combines computer vision, embedded systems, and robotics into an affordable platform that showcases how visual markers can enable reliable autonomous navigation using off-the-shelf hardware.

The Problem

Many autonomous robots rely on sophisticated navigation systems that require costly sensors, extensive calibration, and significant processing power. These solutions present several challenges:

High hardware costs due to LiDAR, depth cameras, or industrial sensors.
Complex algorithms such as SLAM that demand powerful processors.
Difficult deployment in environments where maps frequently change.
Limited accessibility for students, makers, and educational institutions.
Traditional line-following robots lack flexibility and can only follow fixed paths without understanding destinations or instructions.

As a result, there is a need for a navigation system that is:

Low-cost
Easy to deploy
Simple to maintain
Intelligent enough to make navigation decisions
Suitable for education and rapid prototyping

The Solution

QR Code Follower Robot addresses these challenges by using computer vision as its primary navigation sensor.

A camera continuously scans the environment for QR codes placed on the floor or at strategic checkpoints. Each QR code contains navigation information such as:

Move Forward
Turn Left
Turn Right
Stop
Destination ID
Checkpoint Number
Route Information

The captured image is processed on a Raspberry Pi, where OpenCV decodes the QR code and determines the next movement command. The Raspberry Pi then communicates with an Arduino, which performs real-time motor control, ensuring smooth and accurate robot movement.

The navigation workflow is simple:

Camera captures the QR code.
Raspberry Pi processes the image using computer vision.
QR code is decoded into navigation instructions.
Arduino executes motor commands.
Robot moves to the next checkpoint.
Process repeats until the destination is reached.

This architecture separates high-level vision processing from low-level motor control, resulting in a responsive and modular robotic system.

Key Features

Real-time QR code detection
Computer vision-based navigation
Raspberry Pi image processing
Arduino motor control
Modular hardware architecture
Low-cost implementation
Easy deployment without mapping
Scalable for warehouses, laboratories, and educational robotics

Potential Applications

Smart warehouse navigation
Automated material transport
Educational robotics
Indoor delivery robots
Factory logistics
Hospital service robots
Museum or exhibition guides
Research on autonomous navigation

Impact

By replacing expensive localization technologies with inexpensive printed QR codes and computer vision, this project demonstrates that autonomous navigation can be made affordable, accessible, and scalable. It provides an ideal platform for learning robotics while offering a practical solution for structured indoor environments where reliability, simplicity, and cost-effectiveness are essential.

See the video

https://www.tiktok.com/@kogamakerspace/video/7663632105754184967?is_from_webapp=1&sender_device=pc&web_id=7656580236406605333

Code

/*
 QR Robot Arduino Controller
 Receive command from Raspberry Pi
*/

#define IN1 5
#define IN2 6
#define IN3 9
#define IN4 10

void setup()
{
    Serial.begin(115200);

    pinMode(IN1, OUTPUT);
    pinMode(IN2, OUTPUT);
    pinMode(IN3, OUTPUT);
    pinMode(IN4, OUTPUT);

    stopMotor();
}

void loop()
{
    if (Serial.available())
    {
        String cmd = Serial.readStringUntil('\n');
        cmd.trim();

        if (cmd == "FWD")
            forward();

        else if (cmd == "BACK")
            backward();

        else if (cmd == "LEFT")
            left();

        else if (cmd == "RIGHT")
            right();

        else if (cmd == "STOP")
            stopMotor();
    }
}

void forward()
{
    digitalWrite(IN1, HIGH);
    digitalWrite(IN2, LOW);

    digitalWrite(IN3, HIGH);
    digitalWrite(IN4, LOW);
}

void backward()
{
    digitalWrite(IN1, LOW);
    digitalWrite(IN2, HIGH);

    digitalWrite(IN3, LOW);
    digitalWrite(IN4, HIGH);
}

void left()
{
    digitalWrite(IN1, LOW);
    digitalWrite(IN2, HIGH);

    digitalWrite(IN3, HIGH);
    digitalWrite(IN4, LOW);
}

void right()
{
    digitalWrite(IN1, HIGH);
    digitalWrite(IN2, LOW);

    digitalWrite(IN3, LOW);
    digitalWrite(IN4, HIGH);
}

void stopMotor()
{
    digitalWrite(IN1, LOW);
    digitalWrite(IN2, LOW);

    digitalWrite(IN3, LOW);
    digitalWrite(IN4, LOW);
}

import cv2
import serial
import time

# Arduino Serial
arduino = serial.Serial('/dev/ttyACM0',115200)
time.sleep(2)

detector = cv2.QRCodeDetector()

cap = cv2.VideoCapture(0)

lastCommand=""

while True:

    ret,frame = cap.read()

    if not ret:
        continue

    data,bbox,_ = detector.detectAndDecode(frame)

    if bbox is not None:

        if len(data)>0:

            command=data.upper()

            if command!=lastCommand:

                print("QR :",command)

                arduino.write((command+"\n").encode())

                lastCommand=command

    cv2.imshow("QR Robot",frame)

    key=cv2.waitKey(1)

    if key==27:
        break

cap.release()
cv2.destroyAllWindows()