Rust - Joystick Bricklet

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

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
use std::{error::Error, io};

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

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

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

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

    // Get current position.
    let position = j.get_position().recv()?;

    println!("Position [X]: {}", position.x);
    println!("Position [Y]: {}", position.y);

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

Callback

Download (example_callback.rs)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
use std::{error::Error, io, thread};
use tinkerforge::{ip_connection::IpConnection, joystick_bricklet::*};

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

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

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

    let pressed_receiver = j.get_pressed_callback_receiver();

    // Spawn thread to handle received callback messages.
    // This thread ends when the `j` object
    // is dropped, so there is no need for manual cleanup.
    thread::spawn(move || {
        for _pressed in pressed_receiver {
            println!("Pressed");
        }
    });

    let released_receiver = j.get_released_callback_receiver();

    // Spawn thread to handle received callback messages.
    // This thread ends when the `j` object
    // is dropped, so there is no need for manual cleanup.
    thread::spawn(move || {
        for _released in released_receiver {
            println!("Released");
        }
    });

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

Find Borders

Download (example_find_borders.rs)

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
use std::{error::Error, io, thread};
use tinkerforge::{ip_connection::IpConnection, joystick_bricklet::*};

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

fn main() -> Result<(), Box<dyn Error>> {
    let ipcon = IpConnection::new(); // Create IP connection
    let j = JoystickBricklet::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 0.2 seconds (200ms)
    j.set_debounce_period(200);

    let position_reached_receiver = j.get_position_reached_callback_receiver();

    // Spawn thread to handle received events.
    // This thread ends when the `j`
    // is dropped, so there is no need for manual cleanup.
    thread::spawn(move || {
        for position_reached in position_reached_receiver {
            if position_reached.y == 100 {
                println!("Top");
            } else if position_reached.y == -100 {
                println!("Bottom");
            } else if position_reached.x == 100 {
                println!("Right");
            } else if position_reached.x == -100 {
                println!("Left");
            }
            println!();
        }
    });

    // Configure threshold for position "outside of -99, -99 to 99, 99"
    j.set_position_callback_threshold('o', -99, 99, -99, 99);

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

Creates a new JoystickBricklet 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 JoystickBricklet::get_position(&self) → ConvertingReceiver<Position>

Returns the position of the joystick. The value ranges between -100 and 100 for both axis. The middle position of the joystick is x=0, y=0. The returned values are averaged and calibrated (see JoystickBricklet::calibrate).

If you want to get the position periodically, it is recommended to use the JoystickBricklet::get_position_callback_receiver callback and set the period with JoystickBricklet::set_position_callback_period.

pub fn JoystickBricklet::is_pressed(&self) → ConvertingReceiver<bool>

Returns true if the button is pressed and false otherwise.

It is recommended to use the JoystickBricklet::get_pressed_callback_receiver and JoystickBricklet::get_released_callback_receiver callbacks to handle the button.

Advanced Functions

pub fn JoystickBricklet::get_analog_value(&self) → ConvertingReceiver<AnalogValue>

Returns the values as read by a 12-bit analog-to-digital converter. The values are between 0 and 4095 for both axis.

Note

The values returned by JoystickBricklet::get_position are averaged over several samples to yield less noise, while JoystickBricklet::get_analog_value gives back raw unfiltered analog values. The only reason to use JoystickBricklet::get_analog_value is, if you need the full resolution of the analog-to-digital converter.

If you want the analog values periodically, it is recommended to use the JoystickBricklet::get_analog_value_callback_receiver callback and set the period with JoystickBricklet::set_analog_value_callback_period.

pub fn JoystickBricklet::calibrate(&self) → ConvertingReceiver<()>

Calibrates the middle position of the joystick. If your Joystick Bricklet does not return x=0 and y=0 in the middle position, call this function while the joystick is standing still in the middle position.

The resulting calibration will be saved on the EEPROM of the Joystick Bricklet, thus you only have to calibrate it once.

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

pub fn JoystickBricklet::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:

  • JOYSTICK_BRICKLET_FUNCTION_CALIBRATE = 4
  • JOYSTICK_BRICKLET_FUNCTION_SET_POSITION_CALLBACK_PERIOD = 5
  • JOYSTICK_BRICKLET_FUNCTION_SET_ANALOG_VALUE_CALLBACK_PERIOD = 7
  • JOYSTICK_BRICKLET_FUNCTION_SET_POSITION_CALLBACK_THRESHOLD = 9
  • JOYSTICK_BRICKLET_FUNCTION_SET_ANALOG_VALUE_CALLBACK_THRESHOLD = 11
  • JOYSTICK_BRICKLET_FUNCTION_SET_DEBOUNCE_PERIOD = 13
pub fn JoystickBricklet::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 JoystickBricklet::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 JoystickBricklet::set_position_callback_period(&self, period: u32) → ConvertingReceiver<()>

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

The JoystickBricklet::get_position_callback_receiver callback is only triggered if the position has changed since the last triggering.

The default value is 0.

pub fn JoystickBricklet::get_position_callback_period(&self) → ConvertingReceiver<u32>

Returns the period as set by JoystickBricklet::set_position_callback_period.

pub fn JoystickBricklet::set_analog_value_callback_period(&self, period: u32) → ConvertingReceiver<()>

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

The JoystickBricklet::get_analog_value_callback_receiver callback is only triggered if the analog values have changed since the last triggering.

The default value is 0.

pub fn JoystickBricklet::get_analog_value_callback_period(&self) → ConvertingReceiver<u32>

Returns the period as set by JoystickBricklet::set_analog_value_callback_period.

pub fn JoystickBricklet::set_position_callback_threshold(&self, option: char, min_x: i16, max_x: i16, min_y: i16, max_y: i16) → ConvertingReceiver<()>

Sets the thresholds for the JoystickBricklet::get_position_reached_callback_receiver callback.

The following options are possible:

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

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

The following constants are available for this function:

  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_OFF = 'x'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_OUTSIDE = 'o'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_INSIDE = 'i'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_SMALLER = '<'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_GREATER = '>'
pub fn JoystickBricklet::get_position_callback_threshold(&self) → ConvertingReceiver<PositionCallbackThreshold>

Returns the threshold as set by JoystickBricklet::set_position_callback_threshold.

The following constants are available for this function:

  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_OFF = 'x'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_OUTSIDE = 'o'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_INSIDE = 'i'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_SMALLER = '<'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_GREATER = '>'
pub fn JoystickBricklet::set_analog_value_callback_threshold(&self, option: char, min_x: u16, max_x: u16, min_y: u16, max_y: u16) → ConvertingReceiver<()>

Sets the thresholds for the JoystickBricklet::get_analog_value_reached_callback_receiver callback.

The following options are possible:

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

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

The following constants are available for this function:

  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_OFF = 'x'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_OUTSIDE = 'o'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_INSIDE = 'i'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_SMALLER = '<'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_GREATER = '>'
pub fn JoystickBricklet::get_analog_value_callback_threshold(&self) → ConvertingReceiver<AnalogValueCallbackThreshold>

Returns the threshold as set by JoystickBricklet::set_analog_value_callback_threshold.

The following constants are available for this function:

  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_OFF = 'x'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_OUTSIDE = 'o'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_INSIDE = 'i'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_SMALLER = '<'
  • JOYSTICK_BRICKLET_THRESHOLD_OPTION_GREATER = '>'
pub fn JoystickBricklet::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 JoystickBricklet::get_debounce_period(&self) → ConvertingReceiver<u32>

Returns the debounce period as set by JoystickBricklet::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 JoystickBricklet::get_position_callback_receiver(&self) → ConvertingCallbackReceiver<PositionEvent>

Receivers created with this function receive Position events.

This callback is triggered periodically with the period that is set by JoystickBricklet::set_position_callback_period. The received variable is the position of the joystick.

The JoystickBricklet::get_position_callback_receiver callback is only triggered if the position has changed since the last triggering.

pub fn JoystickBricklet::get_analog_value_callback_receiver(&self) → ConvertingCallbackReceiver<AnalogValueEvent>

Receivers created with this function receive Analog Value events.

This callback is triggered periodically with the period that is set by JoystickBricklet::set_analog_value_callback_period. The members of the received struct are the analog values of the joystick.

The JoystickBricklet::get_analog_value_callback_receiver callback is only triggered if the values have changed since the last triggering.

pub fn JoystickBricklet::get_position_reached_callback_receiver(&self) → ConvertingCallbackReceiver<PositionReachedEvent>

Receivers created with this function receive Position Reached events.

This callback is triggered when the threshold as set by JoystickBricklet::set_position_callback_threshold is reached. The members of the received struct are the position of the joystick.

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

pub fn JoystickBricklet::get_analog_value_reached_callback_receiver(&self) → ConvertingCallbackReceiver<AnalogValueReachedEvent>

Receivers created with this function receive Analog Value Reached events.

This callback is triggered when the threshold as set by JoystickBricklet::set_analog_value_callback_threshold is reached. The members of the received struct are the analog values of the joystick.

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

pub fn JoystickBricklet::get_pressed_callback_receiver(&self) → ConvertingCallbackReceiver<()>

Receivers created with this function receive Pressed events.

This callback is triggered when the button is pressed.
pub fn JoystickBricklet::get_released_callback_receiver(&self) → ConvertingCallbackReceiver<()>

Receivers created with this function receive Released events.

This callback is triggered when the button is released.

Constants

JoystickBricklet::DEVICE_IDENTIFIER

This constant is used to identify a Joystick Bricklet.

The JoystickBricklet::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.

JoystickBricklet::DEVICE_DISPLAY_NAME

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