Project1 - Arduino Barcode & QR Code Reader

1. What You Will Build

In this tutorial, you will learn how to build Project1 - Arduino Barcode & QR Code Reader using Arduino .

By the end of this tutorial, your project will be able to:

• Read data from a barcode/QR scanner using SoftwareSerial.

• Detect whether the scanned data is a QR Code or a Barcode.

• Display categorized scan results on the Serial Monitor.

2. What You Will Learn

After completing this tutorial, you should understand:

• How to connect a barcode/QR scanner to Arduino Uno.

• How to read serial data using SoftwareSerial.

• How to process and analyze scanned data.

• How the code works step by step

3. Components Needed

4. Software Needed

Use the tools below depending on your board.

Libraries Needed

No libraries needed.

5. Circuit Connection

Connect the components as shown below.

Wiring Steps

1. Connect VCC of 5V barcode/QR Scanner to 5V on the board.

2. Connect GND of 5V barcode/QR Scanner to GND on the board.

3. Connect RX pin to GPIO 3.

4. Connect TX pin to GPIO 2.

5. Double-check all wiring before powering the board.

Circuit Diagram

6. Code

#include <SoftwareSerial.h>

SoftwareSerial scanner(2, 3);

String data = "";

void setup() {
  Serial.begin(9600);
  scanner.begin(9600);

  Serial.println("Scanner Ready");
}

void loop() {

  while (scanner.available()) {

    char c = scanner.read();

    if (c == '\n' || c == '\r') {

      if (data.length() > 0) {

        String d = data;
        d.trim();

        // ===== DETECTION LOGIC =====
        if (d.startsWith("http")) {
          Serial.print("QR Code Scanned (URL): ");
        }
        else if (d.length() > 60) {
          Serial.print("QR Code Scanned (DuitNow/Long QR): ");
        }
        else {
          bool onlyNumber = true;

          for (int i = 0; i < d.length(); i++) {
            if (!isDigit(d[i])) {
              onlyNumber = false;
              break;
            }
          }

          if (onlyNumber && d.length() <= 13) {
            Serial.print("Barcode Scanned (Numeric): ");
          }
          else {
            Serial.print("Barcode Scanned (Alphanumeric): ");
          }
        }

        Serial.println(d);
        data = "";
      }

    } else {
      data += c;
    }
  }
}

7. Upload / Run the Project

1. Connect the board to your computer using USB.

2. Open the code in Arduino IDE.

3. Select the correct board.

4. Select the correct port.

5. Click Upload.

6. Open the Serial Monitor if needed.

8. Expected Result

When the project is working correctly:

• The Serial Monitor will display “Scanner Ready” when the Arduino starts.

• Every scanned data will be automatically detected and labeled.

9. Troubleshooting