Struct SerialPort

pub struct SerialPort { /* private fields */ }

A serial port.

Implementations

impl SerialPort

pub fn open(name: impl AsRef<Path>, settings: impl IntoSettings) -> Result<Self>

Open and configure a serial port by path or name.

On Unix systems, the name parameter must be a path to a TTY device. On Windows, it must be the name of a COM device, such as COM1, COM2, etc.

The second argument is used to configure the serial port. For simple cases, you pass a u32 for the baud rate. See IntoSettings for more information.

The library automatically uses the win32 device namespace on Windows, so COM ports above COM9 are supported out of the box.

Example 1: Open a serial port with a specific baud rate and default settings.

SerialPort::open("/dev/ttyUSB0", 115200)?;

Example 2: Open a serial port with full control over the settings.

SerialPort::open("/dev/ttyUSB0", |mut settings: Settings| {
   settings.set_raw();
   settings.set_baud_rate(115200)?;
   settings.set_char_size(CharSize::Bits7);
   settings.set_stop_bits(StopBits::Two);
   settings.set_parity(Parity::Odd);
   settings.set_flow_control(FlowControl::RtsCts);
   Ok(settings)
})?;

pub fn pair() -> Result<(Self, Self)>

Available on crate feature unix only.

Open a connected pair of pseudo-terminals.

pub fn available_ports() -> Result<Vec<PathBuf>>

Get a list of available serial ports.

Not currently supported on all platforms. On unsupported platforms, this function always returns an error.

pub fn set_configuration(&mut self, settings: &Settings) -> Result<()>

Configure (or reconfigure) the serial port.

pub fn get_configuration(&self) -> Result<Settings>

Get the current configuration of the serial port.

This function can fail if the underlying syscall fails, or if the serial port configuration can’t be reported using Settings.

pub fn try_clone(&self) -> Result<Self>

Try to clone the serial port handle.

The cloned object refers to the same serial port.

Mixing reads and writes on different handles to the same serial port from different threads may lead to unexpect results. The data may end up interleaved in unpredictable ways.

pub fn read(&self, buf: &mut [u8]) -> Result<usize>

Read bytes from the serial port.

This is identical to std::io::Read::read(), except that this function takes a const reference &self. This allows you to use the serial port concurrently from multiple threads.

Note that there are no guarantees on which thread receives what data when multiple threads are reading from the serial port. You should normally limit yourself to a single reading thread and a single writing thread.

pub fn read_vectored(&self, buf: &mut [IoSliceMut<'_>]) -> Result<usize>

Read bytes from the serial port into a slice of buffers.

This is identical to std::io::Read::read_vectored(), except that this function takes a const reference &self. This allows you to use the serial port concurrently from multiple threads.

Note that there are no guarantees on which thread receives what data when multiple threads are reading from the serial port. You should normally limit yourself to a single reading thread and a single writing thread.

pub fn is_read_vectored(&self) -> bool

Check if the implementation supports vectored reads.

If this returns false, then Self::read_vectored() will only use the first buffer of the given slice. All platforms except for Windows support vectored reads.

pub fn read_exact(&self, buf: &mut [u8]) -> Result<()>

Read the exact number of bytes required to fill the buffer from the serial port.

This will repeatedly call read() until the entire buffer is filled. Errors of the type std::io::ErrorKind::Interrupted are silently ignored. Any other errors (including timeouts) will be returned immediately.

If this function returns an error, it may already have read some data from the serial port into the provided buffer.

This function is identical to std::io::Read::read_exact(), except that this function takes a const reference &self. This allows you to use the serial port concurrently from multiple threads.

Note that there are no guarantees on which thread receives what data when multiple threads are reading from the serial port. You should normally limit yourself to a single reading thread and a single writing thread.

pub fn write(&self, buf: &[u8]) -> Result<usize>

Write bytes to the serial port.

This is identical to std::io::Write::write(), except that this function takes a const reference &self. This allows you to use the serial port concurrently from multiple threads.

Note that data written to the same serial port from multiple threads may end up interleaved at the receiving side. You should normally limit yourself to a single reading thread and a single writing thread.

pub fn write_all(&self, buf: &[u8]) -> Result<()>

Write all bytes to the serial port.

This will repeatedly call Self::write() until the entire buffer has been written. Errors of the type std::io::ErrorKind::Interrupted are silently ignored. Any other errors (including timeouts) will be returned immediately.

If this function returns an error, it may already have transmitted some data from the buffer over the serial port.

This is identical to std::io::Write::write_all(), except that this function takes a const reference &self. This allows you to use the serial port concurrently from multiple threads.

Note that data written to the same serial port from multiple threads may end up interleaved at the receiving side. You should normally limit yourself to a single reading thread and a single writing thread.

pub fn write_vectored(&self, buf: &[IoSlice<'_>]) -> Result<usize>

Write bytes to the serial port from a slice of buffers.

This is identical to std::io::Write::write_vectored(), except that this function takes a const reference &self. This allows you to use the serial port concurrently from multiple threads.

Note that data written to the same serial port from multiple threads may end up interleaved at the receiving side. You should normally limit yourself to a single reading thread and a single writing thread.

pub fn is_write_vectored(&self) -> bool

Check if the implementation supports vectored writes.

If this returns false, then Self::write_vectored() will only use the first buffer of the given slice. All platforms except for Windows support vectored writes.

pub fn flush(&self) -> Result<()>

Flush all data queued to be written.

This will block until the OS buffer has been fully transmitted.

This is identical to std::io::Write::flush(), except that this function takes a const reference &self.

pub fn set_read_timeout(&mut self, timeout: Duration) -> Result<()>

Set the read timeout for the serial port.

The timeout set by this function is an upper bound on individual calls to read(). Other platform specific time-outs may trigger before this timeout does. Additionally, some functions (like Self::read_exact) perform multiple calls to read().

pub fn get_read_timeout(&self) -> Result<Duration>

Get the read timeout of the serial port.

The timeout set by this function is an upper bound on individual calls to read(). Other platform specific time-outs may trigger before this timeout does. Additionally, some functions (like Self::read_exact) perform multiple calls to read().

pub fn set_write_timeout(&mut self, timeout: Duration) -> Result<()>

Set the write timeout for the serial port.

The timeout set by this function is an upper bound on individual calls to write(). Other platform specific time-outs may trigger before this timeout does. Additionally, some functions (like Self::write_all) perform multiple calls to write().

pub fn get_write_timeout(&self) -> Result<Duration>

Get the write timeout of the serial port.

The timeout set by this function is an upper bound on individual calls to write(). Other platform specific time-outs may trigger before this timeout does. Additionally, some functions (like Self::write_all) perform multiple calls to write().

pub fn get_windows_timeouts(&self) -> Result<CommTimeouts>

Available on crate feature windows only.

Get the platform specific timeouts of a serial port on Windows.

This allows for full control over the platform specifics timeouts, but it is only available on Windows.

Also note that changing the read timeouts can easily lead to the serial port timing out on every read unless you are very careful. Please read the whole article about serial port timeouts on MSDN before using this, including all remarks: https://learn.microsoft.com/en-us/windows/win32/api/winbase/ns-winbase-commtimeouts

You are strongly suggested to use Self::get_read_timeout() and Self::get_write_timeout() instead.

pub fn set_windows_timeouts(&self, timeouts: &CommTimeouts) -> Result<()>

Available on crate feature windows only.

Set the platform specific timeouts of a serial port on Windows.

This allows for full control over the platform specifics timeouts, but it is only available on Windows.

Also note that changing the read timeouts can easily lead to the serial port timing out on every read unless you are very careful. Please read the whole article about serial port timeouts on MSDN before using this, including all remarks: https://learn.microsoft.com/en-us/windows/win32/api/winbase/ns-winbase-commtimeouts

You are strongly suggested to use Self::set_read_timeout() and Self::set_write_timeout() instead.

pub fn discard_buffers(&self) -> Result<()>

Discard the kernel input and output buffers for the serial port.

When you write to a serial port, the data may be put in a buffer by the OS to be transmitted by the actual device later. Similarly, data received on the device can be put in a buffer by the OS untill you read it. This function clears both buffers: any untransmitted data and received but unread data is discarded by the OS.

pub fn discard_input_buffer(&self) -> Result<()>

Discard the kernel input buffers for the serial port.

Data received on the device can be put in a buffer by the OS untill you read it. This function clears that buffer: received but unread data is discarded by the OS.

This is particularly useful when communicating with a device that only responds to commands that you send to it. If you discard the input buffer before sending the command, you discard any noise that may have been received after the last command.

pub fn discard_output_buffer(&self) -> Result<()>

Discard the kernel output buffers for the serial port.

When you write to a serial port, the data is generally put in a buffer by the OS to be transmitted by the actual device later. This function clears that buffer: any untransmitted data is discarded by the OS.

pub fn set_rts(&self, state: bool) -> Result<()>

Set the state of the Ready To Send line.

If hardware flow control is enabled on the serial port, it is platform specific what will happen. The function may fail with an error, or it may silently be ignored. It may even succeed and interfere with the flow control.

pub fn read_cts(&self) -> Result<bool>

Read the state of the Clear To Send line.

If hardware flow control is enabled on the serial port, it is platform specific what will happen. The function may fail with an error, it may return a bogus value, or it may return the actual state of the CTS line.

pub fn set_dtr(&self, state: bool) -> Result<()>

Set the state of the Data Terminal Ready line.

If hardware flow control is enabled on the serial port, it is platform specific what will happen. The function may fail with an error, or it may silently be ignored.

pub fn read_dsr(&self) -> Result<bool>

Read the state of the Data Set Ready line.

If hardware flow control is enabled on the serial port, it is platform specific what will happen. The function may fail with an error, it may return a bogus value, or it may return the actual state of the DSR line.

pub fn read_ri(&self) -> Result<bool>

Read the state of the Ring Indicator line.

This line is also sometimes also called the RNG or RING line.

pub fn read_cd(&self) -> Result<bool>

Read the state of the Carrier Detect (CD) line.

This line is also called the Data Carrier Detect (DCD) line or the Receive Line Signal Detect (RLSD) line.

pub fn set_break(&self, enable: bool) -> Result<()>

Set or clear the break state of the serial port.

The serial port will hold the data line in a logical low state while the break state is enabled. This can be detected as a break condition on the other side of the line.

pub fn get_rs4xx_mode(&self) -> Result<TransceiverMode>

Available on crate feature rs4xx and Linux only.

Get the RS-4xx mode of the serial port transceiver.

This is currently only supported on Linux.

Not all serial ports can be configured in a different mode by software. Some serial ports are always in RS-485 or RS-422 mode, and some may have hardware switches or jumpers to configure the transceiver. In those cases, this function will usually report an error or rs4xx::TransceiverMode::Default, even though the serial port is configured is RS-485 or RS-422 mode.

Note that driver support for this feature is very limited and sometimes inconsistent. Please read all the warnings in the rs4xx module carefully.

pub fn set_rs4xx_mode(&self, mode: impl Into<TransceiverMode>) -> Result<()>

Available on crate feature rs4xx and Linux only.

Set the RS-4xx mode of the serial port transceiver.

This is currently only supported on Linux.

Not all serial ports can be configured in a different mode by software. Some serial ports are always in RS-485 or RS-422 mode, and some may have hardware switches or jumpers to configure the transceiver. In that case, this function will usually return an error, but the port can still be in RS-485 or RS-422 mode.

Note that driver support for this feature is very limited and sometimes inconsistent. Please read all the warnings in the rs4xx module carefully.

Trait Implementations

impl AsFd for SerialPort

fn as_fd(&self) -> BorrowedFd<'_>

Borrows the file descriptor.

impl AsRawFd for SerialPort

fn as_raw_fd(&self) -> RawFd

Extracts the raw file descriptor.

impl Debug for SerialPort

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl From<OwnedFd> for SerialPort

fn from(value: OwnedFd) -> Self

Converts to this type from the input type.

impl From<SerialPort> for OwnedFd

fn from(value: SerialPort) -> Self

Converts to this type from the input type.

impl FromRawFd for SerialPort

unsafe fn from_raw_fd(fd: RawFd) -> Self

Constructs a new instance of Self from the given raw file descriptor.

impl IntoRawFd for SerialPort

fn into_raw_fd(self) -> RawFd

Consumes this object, returning the raw underlying file descriptor.

impl Read for &SerialPort

fn read(&mut self, buf: &mut [u8]) -> Result<usize>

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

fn read_vectored(&mut self, buf: &mut [IoSliceMut<'_>]) -> Result<usize>

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Reads all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Reads all bytes until EOF in this source, appending them to buf.

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>

Reads the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Pull some bytes from this source into the specified buffer.

fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Reads the exact number of bytes required to fill cursor.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R>

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

where Self: Sized,

Creates an adapter which will read at most limit bytes from it.

impl Read for SerialPort

fn read(&mut self, buf: &mut [u8]) -> Result<usize>

Pull some bytes from this source into the specified buffer, returning how many bytes were read.

fn read_vectored(&mut self, buf: &mut [IoSliceMut<'_>]) -> Result<usize>

Like read, except that it reads into a slice of buffers.

fn is_read_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Reader has an efficient read_vectored implementation.

fn read_to_end(&mut self, buf: &mut Vec<u8>) -> Result<usize, Error>

Reads all bytes until EOF in this source, placing them into buf.

fn read_to_string(&mut self, buf: &mut String) -> Result<usize, Error>

Reads all bytes until EOF in this source, appending them to buf.

fn read_exact(&mut self, buf: &mut [u8]) -> Result<(), Error>

Reads the exact number of bytes required to fill buf.

fn read_buf(&mut self, buf: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Pull some bytes from this source into the specified buffer.

fn read_buf_exact(&mut self, cursor: BorrowedCursor<'_>) -> Result<(), Error>

🔬This is a nightly-only experimental API. (read_buf)

Reads the exact number of bytes required to fill cursor.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adaptor for this instance of Read.

fn bytes(self) -> Bytes<Self>

where Self: Sized,

Transforms this Read instance to an Iterator over its bytes.

fn chain<R>(self, next: R) -> Chain<Self, R>

where R: Read, Self: Sized,

Creates an adapter which will chain this stream with another.

fn take(self, limit: u64) -> Take<Self>

where Self: Sized,

Creates an adapter which will read at most limit bytes from it.

impl Write for &SerialPort

fn write(&mut self, buf: &[u8]) -> Result<usize>

Writes a buffer into this writer, returning how many bytes were written.

fn write_vectored(&mut self, buf: &[IoSlice<'_>]) -> Result<usize>

Like write, except that it writes from a slice of buffers.

fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.

impl Write for SerialPort

fn write(&mut self, buf: &[u8]) -> Result<usize>

Writes a buffer into this writer, returning how many bytes were written.

fn write_vectored(&mut self, buf: &[IoSlice<'_>]) -> Result<usize>

Like write, except that it writes from a slice of buffers.

fn flush(&mut self) -> Result<()>

Flushes this output stream, ensuring that all intermediately buffered contents reach their destination.

fn is_write_vectored(&self) -> bool

🔬This is a nightly-only experimental API. (can_vector)

Determines if this Writer has an efficient write_vectored implementation.

fn write_all(&mut self, buf: &[u8]) -> Result<(), Error>

Attempts to write an entire buffer into this writer.

fn write_all_vectored(&mut self, bufs: &mut [IoSlice<'_>]) -> Result<(), Error>

🔬This is a nightly-only experimental API. (write_all_vectored)

Attempts to write multiple buffers into this writer.

fn write_fmt(&mut self, args: Arguments<'_>) -> Result<(), Error>

Writes a formatted string into this writer, returning any error encountered.

fn by_ref(&mut self) -> &mut Self

where Self: Sized,

Creates a “by reference” adapter for this instance of Write.