MATLAB/Octave - Dual Button Bricklet¶

Callback (MATLAB)¶

Download (matlab_example_callback.m)

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function matlab_example_callback()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletDualButton;

    HOST = 'localhost';
    PORT = 4223;
    UID = 'XYZ'; % Change XYZ to the UID of your Dual Button Bricklet

    ipcon = IPConnection(); % Create IP connection
    db = handle(BrickletDualButton(UID, ipcon), 'CallbackProperties'); % Create device object

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

    % Register state changed callback to function cb_state_changed
    set(db, 'StateChangedCallback', @(h, e) cb_state_changed(e));

    input('Press key to exit\n', 's');
    ipcon.disconnect();
end

% Callback function for state changed callback
function cb_state_changed(e)
    if e.buttonL == com.tinkerforge.BrickletDualButton.BUTTON_STATE_PRESSED
        fprintf('Left Button: Pressed\n');
    elseif e.buttonL == com.tinkerforge.BrickletDualButton.BUTTON_STATE_RELEASED
        fprintf('Left Button: Released\n');
    end

    if e.buttonR == com.tinkerforge.BrickletDualButton.BUTTON_STATE_PRESSED
        fprintf('Right Button: Pressed\n');
    elseif e.buttonR == com.tinkerforge.BrickletDualButton.BUTTON_STATE_RELEASED
        fprintf('Right Button: Released\n');
    end

    fprintf('\n');
end

Callback (Octave)¶

Download (octave_example_callback.m)

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function octave_example_callback()
    more off;

    HOST = "localhost";
    PORT = 4223;
    UID = "XYZ"; % Change XYZ to the UID of your Dual Button Bricklet

    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
    db = javaObject("com.tinkerforge.BrickletDualButton", UID, ipcon); % Create device object

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

    % Register state changed callback to function cb_state_changed
    db.addStateChangedCallback(@cb_state_changed);

    input("Press key to exit\n", "s");
    ipcon.disconnect();
end

% Callback function for state changed callback
function cb_state_changed(e)
    if java2int(e.buttonL) == 0
        fprintf("Left Button: Pressed\n");
    elseif java2int(e.buttonL) == 1
        fprintf("Left Button: Released\n");
    end

    if java2int(e.buttonR) == 0
        fprintf("Right Button: Pressed\n");
    elseif java2int(e.buttonR) == 1
        fprintf("Right Button: Released\n");
    end

    fprintf("\n");
end

function int = java2int(value)
    if compare_versions(version(), "3.8", "<=")
        int = value.intValue();
    else
        int = value;
    end
end

Basic Functions¶

class BrickletDualButton(String uid, IPConnection ipcon)¶

Parameters:	uid – Type: String ipcon – Type: IPConnection
Returns:	dualButton – Type: BrickletDualButton

Creates an object with the unique device ID uid.

In MATLAB:

import com.tinkerforge.BrickletDualButton;

dualButton = BrickletDualButton('YOUR_DEVICE_UID', ipcon);

In Octave:

dualButton = java_new("com.tinkerforge.BrickletDualButton", "YOUR_DEVICE_UID", ipcon);

This object can then be used after the IP Connection is connected.

void BrickletDualButton.setLEDState(short ledL, short ledR)¶

Parameters:	ledL – Type: short, Range: See constants, Default: 1 ledR – Type: short, Range: See constants, Default: 1

Sets the state of the LEDs. Possible states are:

• 0 = AutoToggleOn: Enables auto toggle with initially enabled LED.
• 1 = AutoToggleOff: Activates auto toggle with initially disabled LED.
• 2 = On: Enables LED (auto toggle is disabled).
• 3 = Off: Disables LED (auto toggle is disabled).

In auto toggle mode the LED is toggled automatically at each press of a button.

If you just want to set one of the LEDs and don't know the current state of the other LED, you can get the state with getLEDState() or you can use setSelectedLEDState().

The following constants are available for this function:

For ledL:

• BrickletDualButton.LED_STATE_AUTO_TOGGLE_ON = 0
• BrickletDualButton.LED_STATE_AUTO_TOGGLE_OFF = 1
• BrickletDualButton.LED_STATE_ON = 2
• BrickletDualButton.LED_STATE_OFF = 3

For ledR:

• BrickletDualButton.LED_STATE_AUTO_TOGGLE_ON = 0
• BrickletDualButton.LED_STATE_AUTO_TOGGLE_OFF = 1
• BrickletDualButton.LED_STATE_ON = 2
• BrickletDualButton.LED_STATE_OFF = 3

BrickletDualButton.LEDState BrickletDualButton.getLEDState()¶

Return Object:	ledL – Type: short, Range: See constants, Default: 1 ledR – Type: short, Range: See constants, Default: 1

Returns the current state of the LEDs, as set by setLEDState().

The following constants are available for this function:

For ledL:

• BrickletDualButton.LED_STATE_AUTO_TOGGLE_ON = 0
• BrickletDualButton.LED_STATE_AUTO_TOGGLE_OFF = 1
• BrickletDualButton.LED_STATE_ON = 2
• BrickletDualButton.LED_STATE_OFF = 3

For ledR:

• BrickletDualButton.LED_STATE_AUTO_TOGGLE_ON = 0
• BrickletDualButton.LED_STATE_AUTO_TOGGLE_OFF = 1
• BrickletDualButton.LED_STATE_ON = 2
• BrickletDualButton.LED_STATE_OFF = 3

BrickletDualButton.ButtonState BrickletDualButton.getButtonState()¶

Return Object:	buttonL – Type: short, Range: See constants buttonR – Type: short, Range: See constants

Returns the current state for both buttons. Possible states are:

• 0 = pressed
• 1 = released

The following constants are available for this function:

For buttonL:

• BrickletDualButton.BUTTON_STATE_PRESSED = 0
• BrickletDualButton.BUTTON_STATE_RELEASED = 1

For buttonR:

• BrickletDualButton.BUTTON_STATE_PRESSED = 0
• BrickletDualButton.BUTTON_STATE_RELEASED = 1

Advanced Functions¶

void BrickletDualButton.setSelectedLEDState(short led, short state)¶

Parameters:	led – Type: short, Range: See constants state – Type: short, Range: See constants

Sets the state of the selected LED (0 or 1).

The other LED remains untouched.

The following constants are available for this function:

For led:

• BrickletDualButton.LED_LEFT = 0
• BrickletDualButton.LED_RIGHT = 1

For state:

• BrickletDualButton.LED_STATE_AUTO_TOGGLE_ON = 0
• BrickletDualButton.LED_STATE_AUTO_TOGGLE_OFF = 1
• BrickletDualButton.LED_STATE_ON = 2
• BrickletDualButton.LED_STATE_OFF = 3

BrickletDualButton.Identity BrickletDualButton.getIdentity()¶

Return Object:

uid – Type: String, Length: up to 8 connectedUid – Type: String, Length: up to 8 position – Type: char, Range: ['a' to 'h', 'z'] hardwareVersion – Type: short[], Length: 3 1: major – Type: short, Range: [0 to 255] 2: minor – Type: short, Range: [0 to 255] 3: revision – Type: short, Range: [0 to 255] firmwareVersion – Type: short[], Length: 3 1: major – Type: short, Range: [0 to 255] 2: minor – Type: short, Range: [0 to 255] 3: revision – Type: short, Range: [0 to 255] deviceIdentifier – Type: int, Range: [0 to 216 - 1]

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', 'd', 'e', 'f', 'g' or 'h' (Bricklet Port). A Bricklet connected to an Isolator Bricklet is always at position 'z'.

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

Callbacks¶

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done with "set" function of MATLAB. The parameters consist of the IP Connection object, the callback name and the callback function. For example, it looks like this in MATLAB:

function my_callback(e)
    fprintf('Parameter: %s\n', e.param);
end

set(device, 'ExampleCallback', @(h, e) my_callback(e));

Due to a difference in the Octave Java support the "set" function cannot be used in Octave. The registration is done with "add*Callback" functions of the device object. It looks like this in Octave:

function my_callback(e)
    fprintf("Parameter: %s\n", e.param);
end

device.addExampleCallback(@my_callback);

It is possible to add several callbacks and to remove them with the corresponding "remove*Callback" function.

The parameters of the callback are passed to the callback function as fields of the structure e, which is derived from the java.util.EventObject class. The available callback names with corresponding structure fields are described below.

callback BrickletDualButton.StateChangedCallback¶

Event Object:	buttonL – Type: short, Range: See constants buttonR – Type: short, Range: See constants ledL – Type: short, Range: See constants ledR – Type: short, Range: See constants

This callback is called whenever a button is pressed.

Possible states for buttons are:

• 0 = pressed
• 1 = released

Possible states for LEDs are:

• 0 = AutoToggleOn: Auto toggle enabled and LED on.
• 1 = AutoToggleOff: Auto toggle enabled and LED off.
• 2 = On: LED on (auto toggle is disabled).
• 3 = Off: LED off (auto toggle is disabled).

The following constants are available for this function:

For buttonL:

• BrickletDualButton.BUTTON_STATE_PRESSED = 0
• BrickletDualButton.BUTTON_STATE_RELEASED = 1

For buttonR:

• BrickletDualButton.BUTTON_STATE_PRESSED = 0
• BrickletDualButton.BUTTON_STATE_RELEASED = 1

For ledL:

• BrickletDualButton.LED_STATE_AUTO_TOGGLE_ON = 0
• BrickletDualButton.LED_STATE_AUTO_TOGGLE_OFF = 1
• BrickletDualButton.LED_STATE_ON = 2
• BrickletDualButton.LED_STATE_OFF = 3

For ledR:

• BrickletDualButton.LED_STATE_AUTO_TOGGLE_ON = 0
• BrickletDualButton.LED_STATE_AUTO_TOGGLE_OFF = 1
• BrickletDualButton.LED_STATE_ON = 2
• BrickletDualButton.LED_STATE_OFF = 3

In MATLAB the set() function can be used to register a callback function to this callback.

In Octave a callback function can be added to this callback using the addStateChangedCallback() function. An added callback function can be removed with the removeStateChangedCallback() function.

Virtual Functions¶

Virtual functions don't communicate with the device itself, but operate only on the API bindings device object. They can be called without the corresponding IP Connection object being connected.

short[] BrickletDualButton.getAPIVersion()¶

Return Object:	apiVersion – Type: short[], Length: 3 1: major – Type: short, Range: [0 to 255] 2: minor – Type: short, Range: [0 to 255] 3: revision – Type: short, Range: [0 to 255]

Returns the version of the API definition 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.

boolean BrickletDualButton.getResponseExpected(byte functionId)¶

Parameters:	functionId – Type: byte, Range: See constants
Returns:	responseExpected – Type: boolean

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 setResponseExpected(). 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 sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For functionId:

• BrickletDualButton.FUNCTION_SET_LED_STATE = 1
• BrickletDualButton.FUNCTION_SET_SELECTED_LED_STATE = 5

void BrickletDualButton.setResponseExpected(byte functionId, boolean responseExpected)¶

Parameters:	functionId – Type: byte, Range: See constants responseExpected – Type: boolean

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 sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For functionId:

• BrickletDualButton.FUNCTION_SET_LED_STATE = 1
• BrickletDualButton.FUNCTION_SET_SELECTED_LED_STATE = 5

void BrickletDualButton.setResponseExpectedAll(boolean responseExpected)¶

Parameters:	responseExpected – Type: boolean

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

Constants¶

int BrickletDualButton.DEVICE_IDENTIFIER¶

This constant is used to identify a Dual Button Bricklet.

The getIdentity() function and the IPConnection.EnumerateCallback callback of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

String BrickletDualButton.DEVICE_DISPLAY_NAME¶

This constant represents the human readable name of a Dual Button Bricklet.