Deutsch
English
Menu

MATLAB/Octave - Dual Button Bricklet

This is the description of the MATLAB/Octave API bindings for the Dual Button Bricklet. General information and technical specifications for the Dual Button Bricklet are summarized in its hardware description.

An installation guide for the MATLAB/Octave API bindings is part of their general description.

Examples

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

Callback (MATLAB)

Download (matlab_example_callback.m)

 1function matlab_example_callback()
 2    import com.tinkerforge.IPConnection;
 3    import com.tinkerforge.BrickletDualButton;
 4
 5    HOST = 'localhost';
 6    PORT = 4223;
 7    UID = 'XYZ'; % Change XYZ to the UID of your Dual Button Bricklet
 8
 9    ipcon = IPConnection(); % Create IP connection
10    db = handle(BrickletDualButton(UID, ipcon), 'CallbackProperties'); % Create device object
11
12    ipcon.connect(HOST, PORT); % Connect to brickd
13    % Don't use device before ipcon is connected
14
15    % Register state changed callback to function cb_state_changed
16    set(db, 'StateChangedCallback', @(h, e) cb_state_changed(e));
17
18    input('Press key to exit\n', 's');
19    ipcon.disconnect();
20end
21
22% Callback function for state changed callback
23function cb_state_changed(e)
24    if e.buttonL == com.tinkerforge.BrickletDualButton.BUTTON_STATE_PRESSED
25        fprintf('Left Button: Pressed\n');
26    elseif e.buttonL == com.tinkerforge.BrickletDualButton.BUTTON_STATE_RELEASED
27        fprintf('Left Button: Released\n');
28    end
29
30    if e.buttonR == com.tinkerforge.BrickletDualButton.BUTTON_STATE_PRESSED
31        fprintf('Right Button: Pressed\n');
32    elseif e.buttonR == com.tinkerforge.BrickletDualButton.BUTTON_STATE_RELEASED
33        fprintf('Right Button: Released\n');
34    end
35
36    fprintf('\n');
37end

Callback (Octave)

Download (octave_example_callback.m)

 1function octave_example_callback()
 2    more off;
 3
 4    HOST = "localhost";
 5    PORT = 4223;
 6    UID = "XYZ"; % Change XYZ to the UID of your Dual Button Bricklet
 7
 8    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
 9    db = javaObject("com.tinkerforge.BrickletDualButton", UID, ipcon); % Create device object
10
11    ipcon.connect(HOST, PORT); % Connect to brickd
12    % Don't use device before ipcon is connected
13
14    % Register state changed callback to function cb_state_changed
15    db.addStateChangedCallback(@cb_state_changed);
16
17    input("Press key to exit\n", "s");
18    ipcon.disconnect();
19end
20
21% Callback function for state changed callback
22function cb_state_changed(e)
23    if java2int(e.buttonL) == 0
24        fprintf("Left Button: Pressed\n");
25    elseif java2int(e.buttonL) == 1
26        fprintf("Left Button: Released\n");
27    end
28
29    if java2int(e.buttonR) == 0
30        fprintf("Right Button: Pressed\n");
31    elseif java2int(e.buttonR) == 1
32        fprintf("Right Button: Released\n");
33    end
34
35    fprintf("\n");
36end
37
38function int = java2int(value)
39    if compare_versions(version(), "3.8", "<=")
40        int = value.intValue();
41    else
42        int = value;
43    end
44end

API

Generally, every method of the MATLAB bindings that returns a value can throw a TimeoutException. This exception gets thrown if the device did not respond. If a cable based connection is used, it is unlikely that this exception gets thrown (assuming nobody unplugs the device). However, if a wireless connection is used, timeouts will occur if the distance to the device gets too big.

Beside the TimeoutException there is also a NotConnectedException that is thrown if a method needs to communicate with the device while the IP Connection is not connected.

Since the MATLAB bindings are based on Java and Java does not support multiple return values and return by reference is not possible for primitive types, we use small classes that only consist of member variables. The member variables of the returned objects are described in the corresponding method descriptions.

The package for all Brick/Bricklet bindings and the IP Connection is com.tinkerforge.*

All methods listed below are thread-safe.

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.

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.

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.