Rust - RS232 Bricklet

This is the description of the Rust API bindings for the RS232 Bricklet. General information and technical specifications for the RS232 Bricklet are summarized in its hardware description.

An installation guide for the Rust API bindings is part of their general description. Additional documentation can be found on docs.rs.

Examples

The example code below is Public Domain (CC0 1.0).

Loopback

Download (example_loopback.rs)

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use std::{error::Error, io, thread};
use tinkerforge::{ip_connection::IpConnection, rs232_bricklet::*};

// For this example connect the RX1 and TX pin to receive the send message

const HOST: &str = "127.0.0.1";
const PORT: u16 = 4223;
const UID: &str = "XYZ"; // Change XYZ to the UID of your RS232 Bricklet

fn main() -> Result<(), Box<dyn Error>> {
    let ipcon = IpConnection::new(); // Create IP connection
    let rs232 = Rs232Bricklet::new(UID, &ipcon); // Create device object

    ipcon.connect((HOST, PORT)).recv()??; // Connect to brickd
                                          // Don't use device before ipcon is connected

    let read_receiver = rs232.get_read_callback_receiver();

    // Spawn thread to handle received events.
    // This thread ends when the `rs232` object
    // is dropped, so there is no need for manual cleanup.
    thread::spawn(move || {
        for read in read_receiver {
            let message: String = read.message.iter().collect();
            println!("Message (Length: {}) {}", read.length, message);
        }
    });

    // Enable read callback
    rs232.enable_read_callback();

    let mut chars = ['\0'; 60];
    let test_chars = ['t', 'e', 's', 't'];
    chars[0..4].copy_from_slice(&test_chars);

    // Write "test" string
    rs232.write(chars, 4);

    println!("Press enter to exit.");
    let mut _input = String::new();
    io::stdin().read_line(&mut _input)?;
    ipcon.disconnect();
    Ok(())
}

API

To allow non-blocking usage, nearly every function of the Rust bindings returns a wrapper around a mpsc::Receiver. To block until the function has finished and get your result, call one of the receiver's recv variants. Those return either the result sent by the device, or any error occured.

Functions returning a result directly will block until the device has finished processing the request.

All functions listed below are thread-safe, those which return a receiver are lock-free.

Basic Functions

pub fn Rs232Bricklet::new(uid: &str, ip_connection: &IpConnection) → Rs232Bricklet

Creates a new Rs232Bricklet object with the unique device ID uid and adds it to the IPConnection ipcon:

This device object can be used after the IP connection has been connected (see examples above).

pub fn Rs232Bricklet::write(&self, message: [char; 60], length: u8) → ConvertingReceiver<u8>

Writes a string of up to 60 characters to the RS232 interface. The string can be binary data, ASCII or similar is not necessary.

The length of the string has to be given as an additional parameter.

The return value is the number of bytes that could be written.

See Rs232Bricklet::set_configuration for configuration possibilities regarding baudrate, parity and so on.

pub fn Rs232Bricklet::read(&self) → ConvertingReceiver<Read>

Returns the currently buffered message. The maximum length of message is 60. If the length is given as 0, there was no new data available.

Instead of polling with this function, you can also use callbacks. See Rs232Bricklet::enable_read_callback and Rs232Bricklet::get_read_callback_receiver callback.

pub fn Rs232Bricklet::set_configuration(&self, baudrate: u8, parity: u8, stopbits: u8, wordlength: u8, hardware_flowcontrol: u8, software_flowcontrol: u8) → ConvertingReceiver<()>

Sets the configuration for the RS232 communication. Available options:

  • Baudrate between 300 and 230400 baud.
  • Parity of none, odd, even or forced parity.
  • Stopbits can be 1 or 2.
  • Word length of 5 to 8.
  • Hard-/Software flow control can either be on or off but not both simultaneously on.

The default is: 115200 baud, parity none, 1 stop bit, word length 8, hard-/software flow control off.

The following constants are available for this function:

  • RS232_BRICKLET_BAUDRATE_300 = 0
  • RS232_BRICKLET_BAUDRATE_600 = 1
  • RS232_BRICKLET_BAUDRATE_1200 = 2
  • RS232_BRICKLET_BAUDRATE_2400 = 3
  • RS232_BRICKLET_BAUDRATE_4800 = 4
  • RS232_BRICKLET_BAUDRATE_9600 = 5
  • RS232_BRICKLET_BAUDRATE_14400 = 6
  • RS232_BRICKLET_BAUDRATE_19200 = 7
  • RS232_BRICKLET_BAUDRATE_28800 = 8
  • RS232_BRICKLET_BAUDRATE_38400 = 9
  • RS232_BRICKLET_BAUDRATE_57600 = 10
  • RS232_BRICKLET_BAUDRATE_115200 = 11
  • RS232_BRICKLET_BAUDRATE_230400 = 12
  • RS232_BRICKLET_PARITY_NONE = 0
  • RS232_BRICKLET_PARITY_ODD = 1
  • RS232_BRICKLET_PARITY_EVEN = 2
  • RS232_BRICKLET_PARITY_FORCED_PARITY_1 = 3
  • RS232_BRICKLET_PARITY_FORCED_PARITY_0 = 4
  • RS232_BRICKLET_STOPBITS_1 = 1
  • RS232_BRICKLET_STOPBITS_2 = 2
  • RS232_BRICKLET_WORDLENGTH_5 = 5
  • RS232_BRICKLET_WORDLENGTH_6 = 6
  • RS232_BRICKLET_WORDLENGTH_7 = 7
  • RS232_BRICKLET_WORDLENGTH_8 = 8
  • RS232_BRICKLET_HARDWARE_FLOWCONTROL_OFF = 0
  • RS232_BRICKLET_HARDWARE_FLOWCONTROL_ON = 1
  • RS232_BRICKLET_SOFTWARE_FLOWCONTROL_OFF = 0
  • RS232_BRICKLET_SOFTWARE_FLOWCONTROL_ON = 1
pub fn Rs232Bricklet::get_configuration(&self) → ConvertingReceiver<Configuration>

Returns the configuration as set by Rs232Bricklet::set_configuration.

The following constants are available for this function:

  • RS232_BRICKLET_BAUDRATE_300 = 0
  • RS232_BRICKLET_BAUDRATE_600 = 1
  • RS232_BRICKLET_BAUDRATE_1200 = 2
  • RS232_BRICKLET_BAUDRATE_2400 = 3
  • RS232_BRICKLET_BAUDRATE_4800 = 4
  • RS232_BRICKLET_BAUDRATE_9600 = 5
  • RS232_BRICKLET_BAUDRATE_14400 = 6
  • RS232_BRICKLET_BAUDRATE_19200 = 7
  • RS232_BRICKLET_BAUDRATE_28800 = 8
  • RS232_BRICKLET_BAUDRATE_38400 = 9
  • RS232_BRICKLET_BAUDRATE_57600 = 10
  • RS232_BRICKLET_BAUDRATE_115200 = 11
  • RS232_BRICKLET_BAUDRATE_230400 = 12
  • RS232_BRICKLET_PARITY_NONE = 0
  • RS232_BRICKLET_PARITY_ODD = 1
  • RS232_BRICKLET_PARITY_EVEN = 2
  • RS232_BRICKLET_PARITY_FORCED_PARITY_1 = 3
  • RS232_BRICKLET_PARITY_FORCED_PARITY_0 = 4
  • RS232_BRICKLET_STOPBITS_1 = 1
  • RS232_BRICKLET_STOPBITS_2 = 2
  • RS232_BRICKLET_WORDLENGTH_5 = 5
  • RS232_BRICKLET_WORDLENGTH_6 = 6
  • RS232_BRICKLET_WORDLENGTH_7 = 7
  • RS232_BRICKLET_WORDLENGTH_8 = 8
  • RS232_BRICKLET_HARDWARE_FLOWCONTROL_OFF = 0
  • RS232_BRICKLET_HARDWARE_FLOWCONTROL_ON = 1
  • RS232_BRICKLET_SOFTWARE_FLOWCONTROL_OFF = 0
  • RS232_BRICKLET_SOFTWARE_FLOWCONTROL_ON = 1
pub fn Rs232Bricklet::set_break_condition(&self, break_time: u16) → ConvertingReceiver<()>

Sets a break condition (the TX output is forced to a logic 0 state). The parameter sets the hold-time of the break condition (in ms).

New in version 2.0.2 (Plugin).

Advanced Functions

pub fn Rs232Bricklet::get_api_version(&self) → [u8; 3]

Returns the version of the API definition (major, minor, revision) implemented by this API bindings. This is neither the release version of this API bindings nor does it tell you anything about the represented Brick or Bricklet.

pub fn Rs232Bricklet::get_response_expected(&mut self, function_id: u8) → bool

Returns the response expected flag for the function specified by the function ID parameter. It is true if the function is expected to send a response, false otherwise.

For getter functions this is enabled by default and cannot be disabled, because those functions will always send a response. For callback configuration functions it is enabled by default too, but can be disabled by Rs232Bricklet::set_response_expected. For setter functions it is disabled by default and can be enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

See Rs232Bricklet::set_response_expected for the list of function ID constants available for this function.

pub fn Rs232Bricklet::set_response_expected(&mut self, function_id: u8, response_expected: bool) → ()

Changes the response expected flag of the function specified by the function ID parameter. This flag can only be changed for setter (default value: false) and callback configuration functions (default value: true). For getter functions it is always enabled.

Enabling the response expected flag for a setter function allows to detect timeouts and other error conditions calls of this setter as well. The device will then send a response for this purpose. If this flag is disabled for a setter function then no response is send and errors are silently ignored, because they cannot be detected.

The following function ID constants are available for this function:

  • RS232_BRICKLET_FUNCTION_ENABLE_READ_CALLBACK = 3
  • RS232_BRICKLET_FUNCTION_DISABLE_READ_CALLBACK = 4
  • RS232_BRICKLET_FUNCTION_SET_CONFIGURATION = 6
  • RS232_BRICKLET_FUNCTION_SET_BREAK_CONDITION = 10
pub fn Rs232Bricklet::set_response_expected_all(&mut self, response_expected: bool) → ()

Changes the response expected flag for all setter and callback configuration functions of this device at once.

pub fn Rs232Bricklet::get_identity(&self) → ConvertingReceiver<Identity>

Returns the UID, the UID where the Bricklet is connected to, the position, the hardware and firmware version as well as the device identifier.

The position can be 'a', 'b', 'c' or 'd'.

The device identifier numbers can be found here. There is also a constant for the device identifier of this Bricklet.

Callback Configuration Functions

pub fn Rs232Bricklet::enable_read_callback(&self) → ConvertingReceiver<()>

Enables the Rs232Bricklet::get_read_callback_receiver callback.

By default the callback is disabled.

pub fn Rs232Bricklet::disable_read_callback(&self) → ConvertingReceiver<()>

Disables the Rs232Bricklet::get_read_callback_receiver callback.

By default the callback is disabled.

pub fn Rs232Bricklet::is_read_callback_enabled(&self) → ConvertingReceiver<bool>

Returns true if the Rs232Bricklet::get_read_callback_receiver callback is enabled, false otherwise.

Callbacks

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with the corresponding get_*_callback_receiver function, which returns a receiver for callback events.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

pub fn Rs232Bricklet::get_read_callback_receiver(&self) → ConvertingCallbackReceiver<ReadEvent>

Receivers created with this function receive Read events.

This callback is called if new data is available. The message has a maximum size of 60 characters. The actual length of the message is given in addition.

To enable this callback, use Rs232Bricklet::enable_read_callback.

pub fn Rs232Bricklet::get_error_callback_receiver(&self) → ConvertingCallbackReceiver<u8>

Receivers created with this function receive Error events.

This callback is called if an error occurs. Possible errors are overrun, parity or framing error.

The following constants are available for this function:

  • RS232_BRICKLET_ERROR_OVERRUN = 1
  • RS232_BRICKLET_ERROR_PARITY = 2
  • RS232_BRICKLET_ERROR_FRAMING = 4

New in version 2.0.1 (Plugin).

Constants

Rs232Bricklet::DEVICE_IDENTIFIER

This constant is used to identify a RS232 Bricklet.

The Rs232Bricklet::get_identity function and the IpConnection::get_enumerate_callback_receiver callback of the IP Connection have a device_identifier parameter to specify the Brick's or Bricklet's type.

Rs232Bricklet::DEVICE_DISPLAY_NAME

This constant represents the human readable name of a RS232 Bricklet.