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alphasignpy

A comprehensive, modern Python library for controlling Alpha Sign LED displays over serial (RS-232 / USB-to-serial).

Implements the full Alpha Sign Communications Protocol (M-Protocol), including all command types, special functions, ACK/NAK error checking, memory configuration, and image display.

Features

  • Comprehensive protocol coverage — Write/Read TEXT (A/B), STRING (G/H), SMALL DOTS (I/J), LARGE DOTS (M/N), RGB DOTS (K/L), SPECIAL FUNCTIONS (E/F), and ALPHAVISION BULLETIN (O/OT).
  • Error checking — Optional ACK/NAK handshake; full exception hierarchy.
  • DTR control — Set or suppress DTR on serial open to prevent accidental sign resets.
  • Image conversion — Automatic conversion from any RGB image to the sign's 9-colour palette using Euclidean nearest-neighbour colour matching.
  • Text formatting helpers — Fluent API for colours, fonts, speed, date, time, animation, and counters.
  • Comprehensive test suite — 210 tests, all passing, with serial I/O mocked for offline development.

Quick Start

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

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

# Configure a TEXT file in 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 message
from alphasign.text_format import color, font
from alphasign.protocol import Color, Font

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

sign.close()

Installation

pip install alphasignpy

Or from source:

git clone https://github.com/lancereinsmith/alphasignpy.git
cd alphasignpy
pip install -e ".[dev]"

Credits

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