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MATLAB/Octave - RGB LED Button Bricklet

This is the description of the MATLAB/Octave API bindings for the RGB LED Button Bricklet. General information and technical specifications for the RGB LED 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).

Simple Color (MATLAB)

Download (matlab_example_simple_color.m)

 1function matlab_example_simple_color()
 2    import com.tinkerforge.IPConnection;
 3    import com.tinkerforge.BrickletRGBLEDButton;
 4
 5    HOST = 'localhost';
 6    PORT = 4223;
 7    UID = 'XYZ'; % Change XYZ to the UID of your RGB LED Button Bricklet
 8
 9    ipcon = IPConnection(); % Create IP connection
10    rlb = handle(BrickletRGBLEDButton(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    % Set light blue color
16    rlb.setColor(0, 170, 234);
17
18    input('Press key to exit\n', 's');
19    ipcon.disconnect();
20end

Simple Button (MATLAB)

Download (matlab_example_simple_button.m)

 1function matlab_example_simple_button()
 2    import com.tinkerforge.IPConnection;
 3    import com.tinkerforge.BrickletRGBLEDButton;
 4
 5    HOST = 'localhost';
 6    PORT = 4223;
 7    UID = 'XYZ'; % Change XYZ to the UID of your RGB LED Button Bricklet
 8
 9    ipcon = IPConnection(); % Create IP connection
10    rlb = handle(BrickletRGBLEDButton(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    % Get current button state
16    state = rlb.getButtonState();
17
18    if state == BrickletRGBLEDButton.BUTTON_STATE_PRESSED
19        fprintf('State: Pressed\n');
20    elseif state == BrickletRGBLEDButton.BUTTON_STATE_RELEASED
21        fprintf('State: Released\n');
22    end
23
24    input('Press key to exit\n', 's');
25    ipcon.disconnect();
26end

Callback (MATLAB)

Download (matlab_example_callback.m)

 1function matlab_example_callback()
 2    import com.tinkerforge.IPConnection;
 3    import com.tinkerforge.BrickletRGBLEDButton;
 4
 5    HOST = 'localhost';
 6    PORT = 4223;
 7    UID = 'XYZ'; % Change XYZ to the UID of your RGB LED Button Bricklet
 8
 9    ipcon = IPConnection(); % Create IP connection
10    rlb = handle(BrickletRGBLEDButton(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 button state changed callback to function cb_button_state_changed
16    set(rlb, 'ButtonStateChangedCallback', @(h, e) cb_button_state_changed(e));
17
18    input('Press key to exit\n', 's');
19    ipcon.disconnect();
20end
21
22% Callback function for button state changed callback
23function cb_button_state_changed(e)
24    if e.state == com.tinkerforge.BrickletRGBLEDButton.BUTTON_STATE_PRESSED
25        fprintf('State: Pressed\n');
26    elseif e.state == com.tinkerforge.BrickletRGBLEDButton.BUTTON_STATE_RELEASED
27        fprintf('State: Released\n');
28    end
29end

Simple Color (Octave)

Download (octave_example_simple_color.m)

 1function octave_example_simple_color()
 2    more off;
 3
 4    HOST = "localhost";
 5    PORT = 4223;
 6    UID = "XYZ"; % Change XYZ to the UID of your RGB LED Button Bricklet
 7
 8    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
 9    rlb = javaObject("com.tinkerforge.BrickletRGBLEDButton", 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    % Set light blue color
15    rlb.setColor(0, 170, 234);
16
17    input("Press key to exit\n", "s");
18    ipcon.disconnect();
19end

Simple Button (Octave)

Download (octave_example_simple_button.m)

 1function octave_example_simple_button()
 2    more off;
 3
 4    HOST = "localhost";
 5    PORT = 4223;
 6    UID = "XYZ"; % Change XYZ to the UID of your RGB LED Button Bricklet
 7
 8    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
 9    rlb = javaObject("com.tinkerforge.BrickletRGBLEDButton", 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    % Get current button state
15    state = rlb.getButtonState();
16
17    if state == 0
18        fprintf("State: Pressed\n");
19    elseif state == 1
20        fprintf("State: Released\n");
21    end
22
23    input("Press key to exit\n", "s");
24    ipcon.disconnect();
25end

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 RGB LED Button Bricklet
 7
 8    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
 9    rlb = javaObject("com.tinkerforge.BrickletRGBLEDButton", 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 button state changed callback to function cb_button_state_changed
15    rlb.addButtonStateChangedCallback(@cb_button_state_changed);
16
17    input("Press key to exit\n", "s");
18    ipcon.disconnect();
19end
20
21% Callback function for button state changed callback
22function cb_button_state_changed(e)
23    if e.state == 0
24        fprintf("State: Pressed\n");
25    elseif e.state == 1
26        fprintf("State: Released\n");
27    end
28end

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 BrickletRGBLEDButton(String uid, IPConnection ipcon)
Parameters:
  • uid – Type: String
  • ipcon – Type: IPConnection
Returns:
  • rgbLEDButton – Type: BrickletRGBLEDButton

Creates an object with the unique device ID uid.

In MATLAB:

import com.tinkerforge.BrickletRGBLEDButton;

rgbLEDButton = BrickletRGBLEDButton('YOUR_DEVICE_UID', ipcon);

In Octave:

rgbLEDButton = java_new("com.tinkerforge.BrickletRGBLEDButton", "YOUR_DEVICE_UID", ipcon);

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

void BrickletRGBLEDButton.setColor(int red, int green, int blue)
Parameters:
  • red – Type: int, Range: [0 to 255], Default: 0
  • green – Type: int, Range: [0 to 255], Default: 0
  • blue – Type: int, Range: [0 to 255], Default: 0

Sets the color of the LED.

BrickletRGBLEDButton.Color BrickletRGBLEDButton.getColor()
Return Object:
  • red – Type: int, Range: [0 to 255], Default: 0
  • green – Type: int, Range: [0 to 255], Default: 0
  • blue – Type: int, Range: [0 to 255], Default: 0

Returns the LED color as set by setColor().

int BrickletRGBLEDButton.getButtonState()
Returns:
  • state – Type: int, Range: See constants

Returns the current state of the button (either pressed or released).

The following constants are available for this function:

For state:

  • BrickletRGBLEDButton.BUTTON_STATE_PRESSED = 0

  • BrickletRGBLEDButton.BUTTON_STATE_RELEASED = 1

BrickletRGBLEDButton.ColorCalibration BrickletRGBLEDButton.getColorCalibration()
Return Object:
  • red – Type: int, Unit: 1 %, Range: [0 to 100], Default: 100
  • green – Type: int, Unit: 1 %, Range: [0 to 100], Default: 100
  • blue – Type: int, Unit: 1 %, Range: [0 to 100], Default: 55

Returns the color calibration as set by setColorCalibration().

Advanced Functions

void BrickletRGBLEDButton.setColorCalibration(int red, int green, int blue)
Parameters:
  • red – Type: int, Unit: 1 %, Range: [0 to 100], Default: 100
  • green – Type: int, Unit: 1 %, Range: [0 to 100], Default: 100
  • blue – Type: int, Unit: 1 %, Range: [0 to 100], Default: 55

Sets a color calibration. Some colors appear brighter then others, so a calibration may be necessary for uniform colors.

The calibration is saved in flash. You don't need to call this function on every startup.

BrickletRGBLEDButton.SPITFPErrorCount BrickletRGBLEDButton.getSPITFPErrorCount()
Return Object:
  • errorCountAckChecksum – Type: long, Range: [0 to 232 - 1]
  • errorCountMessageChecksum – Type: long, Range: [0 to 232 - 1]
  • errorCountFrame – Type: long, Range: [0 to 232 - 1]
  • errorCountOverflow – Type: long, Range: [0 to 232 - 1]

Returns the error count for the communication between Brick and Bricklet.

The errors are divided into

  • ACK checksum errors,

  • message checksum errors,

  • framing errors and

  • overflow errors.

The errors counts are for errors that occur on the Bricklet side. All Bricks have a similar function that returns the errors on the Brick side.

void BrickletRGBLEDButton.setStatusLEDConfig(int config)
Parameters:
  • config – Type: int, Range: See constants, Default: 3

Sets the status LED configuration. By default the LED shows communication traffic between Brick and Bricklet, it flickers once for every 10 received data packets.

You can also turn the LED permanently on/off or show a heartbeat.

If the Bricklet is in bootloader mode, the LED is will show heartbeat by default.

The following constants are available for this function:

For config:

  • BrickletRGBLEDButton.STATUS_LED_CONFIG_OFF = 0

  • BrickletRGBLEDButton.STATUS_LED_CONFIG_ON = 1

  • BrickletRGBLEDButton.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2

  • BrickletRGBLEDButton.STATUS_LED_CONFIG_SHOW_STATUS = 3

int BrickletRGBLEDButton.getStatusLEDConfig()
Returns:
  • config – Type: int, Range: See constants, Default: 3

Returns the configuration as set by setStatusLEDConfig()

The following constants are available for this function:

For config:

  • BrickletRGBLEDButton.STATUS_LED_CONFIG_OFF = 0

  • BrickletRGBLEDButton.STATUS_LED_CONFIG_ON = 1

  • BrickletRGBLEDButton.STATUS_LED_CONFIG_SHOW_HEARTBEAT = 2

  • BrickletRGBLEDButton.STATUS_LED_CONFIG_SHOW_STATUS = 3

int BrickletRGBLEDButton.getChipTemperature()
Returns:
  • temperature – Type: int, Unit: 1 °C, Range: [-215 to 215 - 1]

Returns the temperature as measured inside the microcontroller. The value returned is not the ambient temperature!

The temperature is only proportional to the real temperature and it has bad accuracy. Practically it is only useful as an indicator for temperature changes.

void BrickletRGBLEDButton.reset()

Calling this function will reset the Bricklet. All configurations will be lost.

After a reset you have to create new device objects, calling functions on the existing ones will result in undefined behavior!

BrickletRGBLEDButton.Identity BrickletRGBLEDButton.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 BrickletRGBLEDButton.ButtonStateChangedCallback
Event Object:
  • state – Type: int, Range: See constants

This callback is triggered every time the button state changes from pressed to released or from released to pressed.

The parameter is the current state of the button.

The following constants are available for this function:

For state:

  • BrickletRGBLEDButton.BUTTON_STATE_PRESSED = 0

  • BrickletRGBLEDButton.BUTTON_STATE_RELEASED = 1

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 addButtonStateChangedCallback() function. An added callback function can be removed with the removeButtonStateChangedCallback() 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[] BrickletRGBLEDButton.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 BrickletRGBLEDButton.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:

  • BrickletRGBLEDButton.FUNCTION_SET_COLOR = 1

  • BrickletRGBLEDButton.FUNCTION_SET_COLOR_CALIBRATION = 5

  • BrickletRGBLEDButton.FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237

  • BrickletRGBLEDButton.FUNCTION_SET_STATUS_LED_CONFIG = 239

  • BrickletRGBLEDButton.FUNCTION_RESET = 243

  • BrickletRGBLEDButton.FUNCTION_WRITE_UID = 248

void BrickletRGBLEDButton.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:

  • BrickletRGBLEDButton.FUNCTION_SET_COLOR = 1

  • BrickletRGBLEDButton.FUNCTION_SET_COLOR_CALIBRATION = 5

  • BrickletRGBLEDButton.FUNCTION_SET_WRITE_FIRMWARE_POINTER = 237

  • BrickletRGBLEDButton.FUNCTION_SET_STATUS_LED_CONFIG = 239

  • BrickletRGBLEDButton.FUNCTION_RESET = 243

  • BrickletRGBLEDButton.FUNCTION_WRITE_UID = 248

void BrickletRGBLEDButton.setResponseExpectedAll(boolean responseExpected)
Parameters:
  • responseExpected – Type: boolean

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

Internal Functions

Internal functions are used for maintenance tasks such as flashing a new firmware of changing the UID of a Bricklet. These task should be performed using Brick Viewer instead of using the internal functions directly.

int BrickletRGBLEDButton.setBootloaderMode(int mode)
Parameters:
  • mode – Type: int, Range: See constants
Returns:
  • status – Type: int, Range: See constants

Sets the bootloader mode and returns the status after the requested mode change was instigated.

You can change from bootloader mode to firmware mode and vice versa. A change from bootloader mode to firmware mode will only take place if the entry function, device identifier and CRC are present and correct.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

The following constants are available for this function:

For mode:

  • BrickletRGBLEDButton.BOOTLOADER_MODE_BOOTLOADER = 0

  • BrickletRGBLEDButton.BOOTLOADER_MODE_FIRMWARE = 1

  • BrickletRGBLEDButton.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2

  • BrickletRGBLEDButton.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3

  • BrickletRGBLEDButton.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

For status:

  • BrickletRGBLEDButton.BOOTLOADER_STATUS_OK = 0

  • BrickletRGBLEDButton.BOOTLOADER_STATUS_INVALID_MODE = 1

  • BrickletRGBLEDButton.BOOTLOADER_STATUS_NO_CHANGE = 2

  • BrickletRGBLEDButton.BOOTLOADER_STATUS_ENTRY_FUNCTION_NOT_PRESENT = 3

  • BrickletRGBLEDButton.BOOTLOADER_STATUS_DEVICE_IDENTIFIER_INCORRECT = 4

  • BrickletRGBLEDButton.BOOTLOADER_STATUS_CRC_MISMATCH = 5

int BrickletRGBLEDButton.getBootloaderMode()
Returns:
  • mode – Type: int, Range: See constants

Returns the current bootloader mode, see setBootloaderMode().

The following constants are available for this function:

For mode:

  • BrickletRGBLEDButton.BOOTLOADER_MODE_BOOTLOADER = 0

  • BrickletRGBLEDButton.BOOTLOADER_MODE_FIRMWARE = 1

  • BrickletRGBLEDButton.BOOTLOADER_MODE_BOOTLOADER_WAIT_FOR_REBOOT = 2

  • BrickletRGBLEDButton.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_REBOOT = 3

  • BrickletRGBLEDButton.BOOTLOADER_MODE_FIRMWARE_WAIT_FOR_ERASE_AND_REBOOT = 4

void BrickletRGBLEDButton.setWriteFirmwarePointer(long pointer)
Parameters:
  • pointer – Type: long, Unit: 1 B, Range: [0 to 232 - 1]

Sets the firmware pointer for writeFirmware(). The pointer has to be increased by chunks of size 64. The data is written to flash every 4 chunks (which equals to one page of size 256).

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

int BrickletRGBLEDButton.writeFirmware(int[] data)
Parameters:
  • data – Type: int[], Length: 64, Range: [0 to 255]
Returns:
  • status – Type: int, Range: [0 to 255]

Writes 64 Bytes of firmware at the position as written by setWriteFirmwarePointer() before. The firmware is written to flash every 4 chunks.

You can only write firmware in bootloader mode.

This function is used by Brick Viewer during flashing. It should not be necessary to call it in a normal user program.

void BrickletRGBLEDButton.writeUID(long uid)
Parameters:
  • uid – Type: long, Range: [0 to 232 - 1]

Writes a new UID into flash. If you want to set a new UID you have to decode the Base58 encoded UID string into an integer first.

We recommend that you use Brick Viewer to change the UID.

long BrickletRGBLEDButton.readUID()
Returns:
  • uid – Type: long, Range: [0 to 232 - 1]

Returns the current UID as an integer. Encode as Base58 to get the usual string version.

Constants

int BrickletRGBLEDButton.DEVICE_IDENTIFIER

This constant is used to identify a RGB LED 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 BrickletRGBLEDButton.DEVICE_DISPLAY_NAME

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