serial2-tokio

Serial port communication for tokio.

The serial2-tokio crate provides a cross-platform interface to serial ports. It aims to provide a simpler interface than other alternatives.

Currently supported features:

• Simple interface: one SerialPort struct for all supported platforms.
• List available ports.
• Custom baud rates on all supported platforms except Solaris and Illumos.
• Concurrent reads and writes from multiple tasks, even on Windows.
• Purge the OS buffers (useful to discard read noise when the line should have been silent, for example).
• Read and control individual modem status lines to use them as general purpose I/O.
• Cross platform configuration of serial port settings:
  • Baud rate
  • Character size
  • Stop bits
  • Parity checks
  • Flow control
  • Read/write timeouts

You can open and configure a serial port in one go with SerialPort::open(). The second argument to open() must be a type that implements IntoSettings. In the simplest case, it is enough to pass a u32 for the baud rate. Doing that will also configure a character size of 8 bits with 1 stop bit and disables parity checks and flow control. For full control over the applied settings, pass a closure that receives the the current Settings and return the desired settings. If you do, you will almost always want to call Settings::set_raw() before changing any other settings.

The SerialPort struct implements the standard tokio::io::AsyncRead and tokio::io::AsyncWrite traits, as well as read() and write() functions that take &self instead of &mut self. This allows you to use the serial port concurrently from multiple tasks.

The SerialPort::available_ports() function can be used to get a list of available serial ports on supported platforms.

Example

This example opens a serial port and echoes back everything that is read.

use serial2_tokio::SerialPort;

// On Windows, use something like "COM1".
// For COM ports above COM9, you need to use the win32 device namespace, for example "\\.\COM10" (or "\\\\.\\COM10" with string escaping).
// For more details, see: https://learn.microsoft.com/en-us/windows/win32/fileio/naming-a-file?redirectedfrom=MSDN#win32-device-namespaces
let port = SerialPort::open("/dev/ttyUSB0", 115200)?;
let mut buffer = [0; 256];
loop {
    let read = port.read(&mut buffer).await?;
    port.write(&buffer[..read]).await?;
}