polono-p31s 0.1.0

Python library for Polono P31S thermal label printer via BLE

polono-p31s

A Python library for printing labels on Polono P31S thermal printers via Bluetooth Low Energy (BLE).

Installation

pip install polono-p31s

Quick Start

As a Library

import asyncio
from polono_p31s import PolonoP31S

async def print_label():
    printer = PolonoP31S(width_mm=14, height_mm=40)
    
    # Render text to image
    img = printer.render_text("Hello World", font_size=48)
    
    # Connect and print
    if await printer.connect_ble():
        await printer.print_ble(img)
        await printer.disconnect_ble()

asyncio.run(print_label())

As a CLI Tool

# Print text
polono text "Hello World" --font-size 48

# Print QR code
polono qr "https://example.com"

# Print image
polono image logo.png

# Print barcode
polono barcode "123456789" --type code128

# Preview without printing
polono text "Test" --preview

# Scan for printers
polono scan

Features

• BLE Communication: Connect to P31S printers via Bluetooth Low Energy
• Text Rendering: Print text with customizable fonts, sizes, and alignment
• QR Codes: Generate and print QR codes
• Barcodes: Support for Code128, Code39, EAN13, and more
• Image Printing: Print any image file
• Preview Mode: Generate preview images without printing
• Auto-fit: Automatically scale text to fit labels

Label Specifications

• Default size: 14mm × 40mm with 5mm gap
• Resolution: 203 DPI (8 dots/mm)
• Density: Adjustable 1-15 (default: 15)

API Reference

PolonoP31S Class

class PolonoP31S:
    def __init__(
        self,
        width_mm: float = 14.0,
        height_mm: float = 40.0,
        gap_mm: float = 5.0,
        density: int = 15,
    ): ...

    # Connection
    async def connect_ble(self, address: Optional[str] = None) -> bool: ...
    async def disconnect_ble(self) -> None: ...

    # Rendering (returns PIL Image)
    def render_text(self, text: str, font_size: int = 24, ...) -> Image: ...
    def render_image(self, image_path: str) -> Image: ...
    def render_qr(self, data: str) -> Optional[Image]: ...
    def render_barcode(self, data: str, barcode_type: str = "code128") -> Optional[Image]: ...

    # Printing
    async def print_ble(self, img: Image, copies: int = 1) -> None: ...

    # Utilities
    def check_text_fit(self, text: str, font_size: int) -> dict: ...
    def find_fitting_font_size(self, text: str, max_font_size: int = 200) -> int: ...

Environment Variables

• POLONO_ADDRESS: Default printer BLE address (skips scanning)

Dependencies

• bleak - BLE communication
• Pillow - Image processing
• click - CLI framework
• rich - Console output formatting
• qrcode - QR code generation
• python-barcode - Barcode generation

License

MIT License