async-serialport

async-serialport provides asynchronous I/O halves for serial ports.

The crate is built around a background worker that owns the blocking serial port. Async-facing reader and writer halves communicate with that worker over channels and expose Tokio's standard I/O traits:

• AsyncSerialPort extends serial ports with split.
• Reader implements tokio::io::AsyncRead.
• Writer implements tokio::io::AsyncWrite.
• Worker<T> is the future that owns and drives the blocking serial port.

This design lets async tasks use serial-port reads, writes, and flushes without performing the blocking serial-port operations directly inside the task.

Current API

The public API currently exposes the AsyncSerialPort, Reader, Writer, and Worker types. Call AsyncSerialPort::split on a serial port to receive the async I/O halves and the worker future. Spawn the worker on the async runtime of your choice.

The worker's message protocol is internal. Callers should interact with the async halves through Tokio's AsyncRead and AsyncWrite extension traits.

use async_serialport::AsyncSerialPort;

const BAUD_RATE: u32 = 115_200;
const COMMAND_BUFFER: usize = 16;

let serial_port = serialport::new("/dev/ttyUSB0", BAUD_RATE).open()?;
let (reader, writer, worker) = serial_port.split(COMMAND_BUFFER);

Runtime

The core crate does not require Tokio runtime features. It uses Tokio's runtime-agnostic I/O traits and channels, and returns Worker<T> as a future so callers can choose how to spawn it.

Error Handling

Serial-port errors are returned as std::io::Error values through the async I/O traits. If the worker channel closes before a request completes, the async half returns std::io::ErrorKind::BrokenPipe.

When all async halves are dropped, the worker future finishes and returns the owned serial port.