alphasignpy 0.1.1

Comprehensive Python implementation of the Alpha Sign Communications Protocol for LED signs

alphasignpy

A comprehensive, modern Python library for controlling Alpha Sign LED displays over serial.

Full implementation of the Alpha Sign Communications Protocol (M-Protocol).

Original library by prototux. Rewritten and extended by Lance Reinsmith.

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Documentation

Full API documentation is available at https://lancereinsmith.github.io/alphasignpy/

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Features

• Comprehensive protocol coverage — Write/Read TEXT, STRING, SMALL/LARGE/RGB DOTS, SPECIAL FUNCTIONS, ALPHAVISION BULLETIN
• ACK/NAK error checking with full exception hierarchy
• DTR control to prevent accidental sign resets
• Image conversion from any RGB image to the 9-colour sign palette
• Text formatting helpers — colours, fonts, speed, date/time, animation, counters

Installation

pip install alphasignpy

Quick Start

from alphasign import Sign, Packet, SignType
from alphasign.commands import WriteText, WriteSpecialFunction
from alphasign.protocol import DisplayMode, Color, FileType
from alphasign.text_format import color

# Open connection
sign = Sign(sign_type=SignType.ALPHA_2X0C, address="01")
sign.open("/dev/ttyUSB0", dtr=False)

# Configure memory (one-time setup)
pkt = Packet(type_code=sign.type_code, address=sign.address)
pkt.add(WriteSpecialFunction.configure_memory([
    {"label": "A", "type": FileType.TEXT, "size": 256},
]))
sign.send(pkt)

# Send a coloured message
pkt = Packet(type_code=sign.type_code, address=sign.address)
pkt.add(WriteText(
    color(Color.RED) + b"Hello " + color(Color.GREEN) + b"World!",
    label="A",
    mode=DisplayMode.ROTATE,
))
sign.send(pkt)

sign.close()

Protocol Notes

• Serial framing: 9600 baud, 7E1 (7 data bits, even parity, 1 stop bit)
• Uses binary framing (not ASCII Printable format)
• Timing markers (0xFF) are used to insert 100 ms delays; never transmitted
• Checksums are 16-bit hex sums from STX through ETX

License

MIT License. See LICENSE and NOTICE for details. The original library by prototux was released under the Apache License 2.0.