Rust - CO2 Bricklet

This is the description of the Rust API bindings for the CO2 Bricklet. General information and technical specifications for the CO2 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).

Simple

Download (example_simple.rs)

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use std::{error::Error, io};

use tinkerforge::{co2_bricklet::*, ip_connection::IpConnection};

const HOST: &str = "localhost";
const PORT: u16 = 4223;
const UID: &str = "XYZ"; // Change XYZ to the UID of your CO2 Bricklet.

fn main() -> Result<(), Box<dyn Error>> {
    let ipcon = IpConnection::new(); // Create IP connection.
    let co2 = Co2Bricklet::new(UID, &ipcon); // Create device object.

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

    // Get current CO2 concentration.
    let co2_concentration = co2.get_co2_concentration().recv()?;
    println!("CO2 Concentration: {} ppm", co2_concentration);

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

Callback

Download (example_callback.rs)

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use std::{error::Error, io, thread};
use tinkerforge::{co2_bricklet::*, ip_connection::IpConnection};

const HOST: &str = "localhost";
const PORT: u16 = 4223;
const UID: &str = "XYZ"; // Change XYZ to the UID of your CO2 Bricklet.

fn main() -> Result<(), Box<dyn Error>> {
    let ipcon = IpConnection::new(); // Create IP connection.
    let co2 = Co2Bricklet::new(UID, &ipcon); // Create device object.

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

    let co2_concentration_receiver = co2.get_co2_concentration_callback_receiver();

    // Spawn thread to handle received callback messages.
    // This thread ends when the `co2` object
    // is dropped, so there is no need for manual cleanup.
    thread::spawn(move || {
        for co2_concentration in co2_concentration_receiver {
            println!("CO2 Concentration: {} ppm", co2_concentration);
        }
    });

    // Set period for CO2 concentration receiver to 1s (1000ms).
    // Note: The CO2 concentration callback is only called every second
    //       if the CO2 concentration has changed since the last call!
    co2.set_co2_concentration_callback_period(1000);

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

Threshold

Download (example_threshold.rs)

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use std::{error::Error, io, thread};
use tinkerforge::{co2_bricklet::*, ip_connection::IpConnection};

const HOST: &str = "localhost";
const PORT: u16 = 4223;
const UID: &str = "XYZ"; // Change XYZ to the UID of your CO2 Bricklet.

fn main() -> Result<(), Box<dyn Error>> {
    let ipcon = IpConnection::new(); // Create IP connection.
    let co2 = Co2Bricklet::new(UID, &ipcon); // Create device object.

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

    // Get threshold receivers with a debounce time of 10 seconds (10000ms).
    co2.set_debounce_period(10000);

    let co2_concentration_reached_receiver = co2.get_co2_concentration_reached_callback_receiver();

    // Spawn thread to handle received callback messages.
    // This thread ends when the `co2` object
    // is dropped, so there is no need for manual cleanup.
    thread::spawn(move || {
        for co2_concentration_reached in co2_concentration_reached_receiver {
            println!("CO2 Concentration: {} ppm", co2_concentration_reached);
        }
    });

    // Configure threshold for CO2 concentration "greater than 750 ppm".
    co2.set_co2_concentration_callback_threshold('>', 750, 0);

    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 Co2Bricklet::new(uid: &str, ip_connection: &IpConnection) → Co2Bricklet

Creates a new Co2Bricklet 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 Co2Bricklet::get_co2_concentration(&self) → ConvertingReceiver<u16>

Returns the measured CO2 concentration. The value is in ppm (parts per million) and between 0 to 10000.

If you want to get the CO2 concentration periodically, it is recommended to use the Co2Bricklet::get_co2_concentration_callback_receiver callback and set the period with Co2Bricklet::set_co2_concentration_callback_period.

Advanced Functions

pub fn Co2Bricklet::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 Co2Bricklet::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 Co2Bricklet::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 Co2Bricklet::set_response_expected for the list of function ID constants available for this function.

pub fn Co2Bricklet::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:

  • CO2_BRICKLET_FUNCTION_SET_CO2_CONCENTRATION_CALLBACK_PERIOD = 2
  • CO2_BRICKLET_FUNCTION_SET_CO2_CONCENTRATION_CALLBACK_THRESHOLD = 4
  • CO2_BRICKLET_FUNCTION_SET_DEBOUNCE_PERIOD = 6
pub fn Co2Bricklet::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 Co2Bricklet::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 Co2Bricklet::set_co2_concentration_callback_period(&self, period: u32) → ConvertingReceiver<()>

Sets the period in ms with which the Co2Bricklet::get_co2_concentration_callback_receiver callback is triggered periodically. A value of 0 turns the callback off.

The Co2Bricklet::get_co2_concentration_callback_receiver callback is only triggered if the CO2 concentration has changed since the last triggering.

The default value is 0.

pub fn Co2Bricklet::get_co2_concentration_callback_period(&self) → ConvertingReceiver<u32>

Returns the period as set by Co2Bricklet::set_co2_concentration_callback_period.

pub fn Co2Bricklet::set_co2_concentration_callback_threshold(&self, option: char, min: u16, max: u16) → ConvertingReceiver<()>

Sets the thresholds for the Co2Bricklet::get_co2_concentration_reached_callback_receiver callback.

The following options are possible:

Option Description
'x' Callback is turned off
'o' Callback is triggered when the CO2 concentration is outside the min and max values
'i' Callback is triggered when the CO2 concentration is inside the min and max values
'<' Callback is triggered when the CO2 concentration is smaller than the min value (max is ignored)
'>' Callback is triggered when the CO2 concentration is greater than the min value (max is ignored)

The default value is ('x', 0, 0).

The following constants are available for this function:

  • CO2_BRICKLET_THRESHOLD_OPTION_OFF = 'x'
  • CO2_BRICKLET_THRESHOLD_OPTION_OUTSIDE = 'o'
  • CO2_BRICKLET_THRESHOLD_OPTION_INSIDE = 'i'
  • CO2_BRICKLET_THRESHOLD_OPTION_SMALLER = '<'
  • CO2_BRICKLET_THRESHOLD_OPTION_GREATER = '>'
pub fn Co2Bricklet::get_co2_concentration_callback_threshold(&self) → ConvertingReceiver<Co2ConcentrationCallbackThreshold>

Returns the threshold as set by Co2Bricklet::set_co2_concentration_callback_threshold.

The following constants are available for this function:

  • CO2_BRICKLET_THRESHOLD_OPTION_OFF = 'x'
  • CO2_BRICKLET_THRESHOLD_OPTION_OUTSIDE = 'o'
  • CO2_BRICKLET_THRESHOLD_OPTION_INSIDE = 'i'
  • CO2_BRICKLET_THRESHOLD_OPTION_SMALLER = '<'
  • CO2_BRICKLET_THRESHOLD_OPTION_GREATER = '>'
pub fn Co2Bricklet::set_debounce_period(&self, debounce: u32) → ConvertingReceiver<()>

Sets the period in ms with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

The default value is 100.

pub fn Co2Bricklet::get_debounce_period(&self) → ConvertingReceiver<u32>

Returns the debounce period as set by Co2Bricklet::set_debounce_period.

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 Co2Bricklet::get_co2_concentration_callback_receiver(&self) → ConvertingCallbackReceiver<u16>

Receivers created with this function receive CO2 Concentration events.

This callback is triggered periodically with the period that is set by Co2Bricklet::set_co2_concentration_callback_period. The received variable is the CO2 concentration of the sensor.

The Co2Bricklet::get_co2_concentration_callback_receiver callback is only triggered if the CO2 concentration has changed since the last triggering.

pub fn Co2Bricklet::get_co2_concentration_reached_callback_receiver(&self) → ConvertingCallbackReceiver<u16>

Receivers created with this function receive CO2 Concentration Reached events.

This callback is triggered when the threshold as set by Co2Bricklet::set_co2_concentration_callback_threshold is reached. The received variable is the CO2 concentration.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by Co2Bricklet::set_debounce_period.

Constants

Co2Bricklet::DEVICE_IDENTIFIER

This constant is used to identify a CO2 Bricklet.

The Co2Bricklet::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.

Co2Bricklet::DEVICE_DISPLAY_NAME

This constant represents the human readable name of a CO2 Bricklet.