Serio: Modern Asynchronous Serial Communication Library

Serio is a modern asynchronous serial port library for Python 3.11+ that provides efficient, native async I/O without thread pool overhead. It offers both high-level streams API and low-level transport API for serial communication.

Features

• ✅ True async I/O (no thread pool overhead)
• ✅ Python 3.11+ native support
• ✅ Clean, modern API with asyncio integration
• ✅ POSIX and Windows support
• ✅ High-level Streams API (StreamReader/StreamWriter)
• ✅ Low-level Transport API for custom protocols
• ✅ Platform-optimized async I/O (polling on Windows, file descriptors on POSIX)
• ✅ Proper flow control with buffer management
• ✅ Comprehensive exception handling

Installation

pip install serio

Getting Started

High-Level API Example

import asyncio
from serio import open_serial_connection

async def main():
    reader, writer = await open_serial_connection(
        port='/dev/ttyUSB0',
        baudrate=115200
    )
    
    writer.write(b'AT\r\n')
    response = await reader.readuntil(b'\r\n')
    print(f"Received: {response.decode()}")

asyncio.run(main())

Low-Level API Example

import asyncio
from serio import create_serial_connection

class MyProtocol(asyncio.Protocol):
    def connection_made(self, transport):
        print("Connection established")
        
    def data_received(self, data):
        print(f"Received: {data}")
        
    def connection_lost(self, exc):
        print("Connection closed")

async def main():
    loop = asyncio.get_running_loop()
    transport, protocol = await create_serial_connection(
        loop,
        MyProtocol,
        port='/dev/ttyUSB0',
        baudrate=115200
    )
    
    transport.write(b'AT\r\n')
    await asyncio.sleep(1)
    transport.close()

asyncio.run(main())

Context Manager Example

from serio import SerialStream

async def main():
    async with SerialStream(port='/dev/ttyUSB0', baudrate=115200) as (reader, writer):
        writer.write(b'AT\r\n')
        response = await reader.readuntil(b'\r\n')
        print(f"Received: {response.decode()}")

asyncio.run(main())

API Reference

High-Level API

• open_serial_connection(**kwargs) -> (StreamReader, StreamWriter)
• create_serial_connection(loop, protocol_factory, **kwargs) -> (SerialTransport, Protocol)
• SerialStream(**kwargs) - Context manager for serial connections

Low-Level API

• SerialTransport(loop, protocol, serial_instance) - Asynchronous serial transport
• SerialError - Base exception class
• SerialConnectionError - Raised when connection fails
• SerialConfigError - Raised for invalid configuration
• PlatformNotSupportedError - Raised for unsupported platforms

Configuration Parameters

Platform Support

• POSIX: Uses file descriptors for true async I/O
• Windows: Uses efficient polling (5ms intervals)
• Unsupported: Other platforms will raise PlatformNotSupportedError

License

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

Contributing

Contributions are welcome! Please feel free to submit pull requests or open issues.

Author: Semenets V. Pavel
Version: 0.1.2
Email: p.semenets@gmail.com