Grocy Label Printer ESC/P

A Flask server that receives Grocy label requests and prints them to ESC/P thermal printers.

Features

• Grocy Integration: Compatible with Grocy's label printing system
• ESC/P Support: Works with ESC/P thermal printers via network
• QR Code Generation: Automatically generates QR codes from Grocy barcodes
• Smart Layout: QR code at top, product information below
• Font Management: Uses Roboto Bold fonts in multiple sizes
• Container Support: Available as Docker images for easy deployment
• Multi-Architecture: Supports AMD64 and ARM64 architectures

Quick Start

Docker (Recommended)

docker run -d \
  --name grocy-label-printer \
  -p 5000:5000 \
  -e PRINTER_HOST=192.168.1.100 \
  -e PRINTER_PORT=9100 \
  ghcr.io/miguelangel-nubla/grocy-label-printer-escpos:latest

Python Package

pip install grocy-label-printer-escpos
grocy-label-printer-escpos

From Source

git clone https://github.com/miguelangel-nubla/grocy-label-printer-escpos.git
cd grocy-label-printer-escpos
pip install -e .
python -m grocy_label_printer_escpos.server

Configuration

Environment Variables

Grocy Configuration

In Grocy, configure a new label printer:

1. Go to Manage > Label printers
2. Add a new printer with these settings:
   • Name: ESC/P Thermal Printer
   • Type: Generic
   • URL: http://your-server:5000/print
   • HTTP Method: POST

API Endpoints

POST /print

Print a label from Grocy data.

Request Body: Grocy label data (JSON or form-encoded)

Response:

• 200 OK - Label printed successfully
• 400 Bad Request - Invalid or missing data
• 500 Internal Server Error - Print failed

GET|POST /image

Preview label image without printing.

Parameters: Same as /print

Response: PNG image of the label

GET /test

Print a test label with sample data.

Response:

{"status": "success", "message": "Test label printed"}

GET /

Server status and configuration.

Response:

{
  "status": "running",
  "printer": "192.168.1.100:9001",
  "service": "Grocy Thermal Label Server"
}

Label Format

Labels include:

• QR Code: Generated from Grocy barcode (top, centered)
• Product Name: Large bold font (centered)
• Amount & Unit: Medium font (if available)
• Best Before Date: Medium font (if available)
• Purchase Date: Medium font (if available)

Special handling:

• Long product names are automatically split across lines
• Container weight items exclude amount/date information
• Proper singular/plural unit names

Printer Compatibility

Tested with:

• Sunmi integrated 58mm thermal printers

Development

Setup

git clone https://github.com/miguelangel-nubla/grocy-label-printer-escpos.git
cd grocy-label-printer-escpos
pip install -e ".[dev]"
pre-commit install

Testing

pytest

Code Quality

black src/ tests/
isort src/ tests/
flake8 src/ tests/
mypy src/

Building

python -m build

Deployment

Docker Compose

version: '3.8'
services:
  grocy-label-printer:
    image: ghcr.io/miguelangel-nubla/grocy-label-printer-escpos:latest
    ports:
      - "5000:5000"
    environment:
      - PRINTER_HOST=192.168.1.100
      - PRINTER_PORT=9100
    restart: unless-stopped

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: grocy-label-printer
spec:
  replicas: 1
  selector:
    matchLabels:
      app: grocy-label-printer
  template:
    metadata:
      labels:
        app: grocy-label-printer
    spec:
      containers:
      - name: grocy-label-printer
        image: ghcr.io/miguelangel-nubla/grocy-label-printer-escpos:latest
        ports:
        - containerPort: 5000
        env:
        - name: PRINTER_HOST
          value: "192.168.1.100"
        - name: PRINTER_PORT
          value: "9100"
---
apiVersion: v1
kind: Service
metadata:
  name: grocy-label-printer
spec:
  selector:
    app: grocy-label-printer
  ports:
  - port: 5000
    targetPort: 5000

Troubleshooting

Printer Connection Issues

1. Check network connectivity:

   telnet 192.168.1.100 9100
   

2. Verify printer profile: Some printers may need different profiles. Try:

   • TM-T20
   • Generic
   • TM-T88III

3. Check printer logs:

   docker logs grocy-label-printer
   

Label Not Printing

1. Test with sample data:

   curl http://localhost:5000/test
   

2. Check Grocy data format:

   curl -X POST http://localhost:5000/image \
     -H "Content-Type: application/json" \
     -d '{"product": "Test", "grocycode": "123"}'
   

3. Verify printer buffer: Ensure the printer connection is properly closed after each print job.

Contributing

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Add tests if applicable
5. Run the test suite
6. Submit a pull request

License

This project is licensed under the MIT License - see the LICENSE file for details.

Releases

See GitHub Releases for version history and changes.