Build a barcode scanner

To build a barcode scanner, you can either create a hardware-based scanner using a camera and microcontroller or a software-based scanner using a computer or mobile app. Below is a simple guide to building a software barcode scanner using Python, which is great for desktop use.

Build a Barcode Scanner in Python

✅ Requirements

You’ll need the following:

• Python 3.x

• opencv-python (for capturing video)

• pyzbar (for decoding barcodes)

• A webcam (external or laptop integrated)

✅ Installation

Open your terminal or command prompt and install dependencies:

bash
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pip install opencv-python pyzbar

On some systems, you might also need:

bash
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pip install numpy

✅ Python Code for Barcode Scanner

python
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import cv2
from pyzbar.pyzbar import decode

def scan_barcodes():
    cap = cv2.VideoCapture(0)  # 0 is the default webcam

    while True:
        ret, frame = cap.read()
        if not ret:
            break

        # Decode barcodes in the frame
        barcodes = decode(frame)

        for barcode in barcodes:
            barcode_data = barcode.data.decode('utf-8')
            barcode_type = barcode.type

            # Draw rectangle around barcode
            pts = barcode.polygon
            pts = [(pt.x, pt.y) for pt in pts]
            cv2.polylines(frame, [np.array(pts, dtype=np.int32)], True, (255, 0, 255), 2)

            # Display data and type
            cv2.putText(frame, f'{barcode_data} ({barcode_type})', (barcode.rect.left, barcode.rect.top - 10),
                        cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 0), 2)

        cv2.imshow('Barcode Scanner', frame)

        # Exit on pressing 'q'
        if cv2.waitKey(1) & 0xFF == ord('q'):
            break

    cap.release()
    cv2.destroyAllWindows()

if __name__ == '__main__':
    scan_barcodes()

How It Works

1. Captures video from the webcam using OpenCV.

2. Scans each frame for barcodes using pyzbar.

3. Draws bounding boxes and displays the decoded content on the screen.

4. Exits the scanner when you press the “q” key.

Barcode Formats Supported

The pyzbar library supports multiple types:

• EAN-13

• UPC-A

• Code 128

• QR Codes

• Code 39

• Interleaved 2 of 5

Enhancements You Can Add

• Export scanned data to a CSV file

• Add sound on successful scan

• Support for multiple barcode entries

• GUI using Tkinter or PyQt

• Mobile version using Kivy or React Native with a camera module

Notes

• Ensure good lighting for accurate scanning.

• Some barcodes may be damaged or unclear, requiring better quality input.

• If building for mobile, consider native SDKs like Google ML Kit or Zxing.

Let me know if you want to build a hardware scanner with Arduino or Raspberry Pi.