MATLAB/Octave - OLED 64x48 Bricklet

This is the description of the MATLAB/Octave API bindings for the OLED 64x48 Bricklet. General information and technical specifications for the OLED 64x48 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).

Hello World (MATLAB)

Download (matlab_example_hello_world.m)

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function matlab_example_hello_world()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletOLED64x48;

    HOST = 'localhost';
    PORT = 4223;
    UID = 'XYZ'; % Change XYZ to the UID of your OLED 64x48 Bricklet

    ipcon = IPConnection(); % Create IP connection
    oled = handle(BrickletOLED64x48(UID, ipcon), 'CallbackProperties'); % Create device object

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

    % Clear display
    oled.clearDisplay();

    % Write "Hello World" starting from upper left corner of the screen
    oled.writeLine(0, 0, 'Hello World');

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

Pixel Matrix (MATLAB)

Download (matlab_example_pixel_matrix.m)

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function matlab_example_pixel_matrix()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletOLED64x48;

    HOST = 'localhost';
    PORT = 4223;
    UID = 'XYZ'; % Change XYZ to the UID of your OLED 64x48 Bricklet
    SCREEN_WIDTH = 64;
    SCREEN_HEIGHT = 48;

    function draw_matrix(oled, pixels)
        column = cell(1, SCREEN_HEIGHT/8);
        for i = 1:(SCREEN_HEIGHT/8) - 1
            column{i} = zeros(1, 64);
            for j = 1:SCREEN_WIDTH
                page = 0;
                for k = 0:7
                    if pixels(i*8 + k, j) == true
                        page = bitor(page, bitshift(1, k));
                    end
                end
                column{i}(j) = page;
            end
        end
        oled.newWindow(0, SCREEN_WIDTH-1, 0, 5);
        for i = 1:(SCREEN_HEIGHT/8) - 1
            oled.write(column{i});
        end
    end

    ipcon = IPConnection(); % Create IP connection
    oled = handle(BrickletOLED64x48(UID, ipcon), 'CallbackProperties'); % Create device object

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

    % Clear display
    oled.clearDisplay();

    % Draw checkerboard pattern
    pixel_matrix = false(SCREEN_HEIGHT, SCREEN_WIDTH);

    for h = 1:SCREEN_HEIGHT
        for w = 1:SCREEN_WIDTH
            pixel_matrix(h, w) = mod(floor(h / 8), 2) == mod(floor(w / 8), 2);
        end
    end

    draw_matrix(oled, pixel_matrix);

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

Hello World (Octave)

Download (octave_example_hello_world.m)

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function octave_example_hello_world()
    more off;

    HOST = "localhost";
    PORT = 4223;
    UID = "XYZ"; % Change XYZ to the UID of your OLED 64x48 Bricklet

    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
    oled = javaObject("com.tinkerforge.BrickletOLED64x48", UID, ipcon); % Create device object

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

    % Clear display
    oled.clearDisplay();

    % Write "Hello World" starting from upper left corner of the screen
    oled.writeLine(0, 0, "Hello World");

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

Pixel Matrix (Octave)

Download (octave_example_pixel_matrix.m)

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function octave_example_pixel_matrix()
    more off;

    HOST = "localhost";
    PORT = 4223;
    UID = "XYZ"; % Change XYZ to the UID of your OLED 64x48 Bricklet
    SCREEN_WIDTH = 64;
    SCREEN_HEIGHT = 48;

    function draw_matrix(oled, pixels)
        SCREEN_WIDTH = 64;
        SCREEN_HEIGHT = 48;
        column = cell(1, SCREEN_HEIGHT/8);
        for i = 1:(SCREEN_HEIGHT/8) - 1
            column{i} = zeros(1, 64);
            for j = 1:SCREEN_WIDTH
                page = 0;
                for k = 0:7
                    if pixels(i*8 + k, j) == true
                        page = bitor(page, bitshift(1, k));
                    end
                end
                column{i}(j) = page;
            end
        end
        oled.newWindow(0, SCREEN_WIDTH-1, 0, 5);
        for i = 1:(SCREEN_HEIGHT/8) - 1
            oled.write(column{i});
        end
    end

    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
    oled = javaObject("com.tinkerforge.BrickletOLED64x48", UID, ipcon); % Create device object

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

    % Clear display
    oled.clearDisplay();

    % Draw checkerboard pattern
    pixel_matrix = false(SCREEN_HEIGHT, SCREEN_WIDTH);

    for h = 1:SCREEN_HEIGHT
        for w = 1:SCREEN_WIDTH
            pixel_matrix(h, w) = mod(floor(h / 8), 2) == mod(floor(w / 8), 2);
        end
    end

    draw_matrix(oled, pixel_matrix);

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

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

public class BrickletOLED64x48(String uid, IPConnection ipcon)

Creates an object with the unique device ID uid.

In MATLAB:

import com.tinkerforge.BrickletOLED64x48;

oled64x48 = BrickletOLED64x48('YOUR_DEVICE_UID', ipcon);

In Octave:

oled64x48 = java_new("com.tinkerforge.BrickletOLED64x48", "YOUR_DEVICE_UID", ipcon);

This object can then be used after the IP Connection is connected (see examples above).

public void write(short[] data)

Appends 64 byte of data to the window as set by newWindow().

Each row has a height of 8 pixels which corresponds to one byte of data.

Example: if you call newWindow() with column from 0 to 63 and row from 0 to 5 (the whole display) each call of write() (red arrow) will write one row.

Display pixel order

The LSB (D0) of each data byte is at the top and the MSB (D7) is at the bottom of the row.

The next call of write() will write the second row and so on. To fill the whole display you need to call write() 6 times.

public void newWindow(short columnFrom, short columnTo, short rowFrom, short rowTo)

Sets the window in which you can write with write(). One row has a height of 8 pixels.

The columns have a range of 0 to 63 and the rows have a range of 0 to 5.

public void clearDisplay()

Clears the current content of the window as set by newWindow().

public void writeLine(short line, short position, String text)

Writes text to a specific line (0 to 5) with a specific position (0 to 12). The text can have a maximum of 13 characters.

For example: (1, 4, "Hello") will write Hello in the middle of the second line of the display.

You can draw to the display with write() and then add text to it afterwards.

The display uses a special 5x7 pixel charset. You can view the characters of the charset in Brick Viewer.

Advanced Functions

public void setDisplayConfiguration(short contrast, boolean invert)

Sets the configuration of the display.

You can set a contrast value from 0 to 255 and you can invert the color (black/white) of the display.

The default values are contrast 143 and inverting off.

public BrickletOLED64x48.DisplayConfiguration getDisplayConfiguration()

Returns the configuration as set by setDisplayConfiguration().

The returned object has the public member variables short contrast and boolean invert.

public short[] getAPIVersion()

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.

public boolean getResponseExpected(short functionId)

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

See setResponseExpected() for the list of function ID constants available for this function.

public void setResponseExpected(short functionId, boolean responseExpected)

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:

  • BrickletOLED64x48.FUNCTION_WRITE = 1
  • BrickletOLED64x48.FUNCTION_NEW_WINDOW = 2
  • BrickletOLED64x48.FUNCTION_CLEAR_DISPLAY = 3
  • BrickletOLED64x48.FUNCTION_SET_DISPLAY_CONFIGURATION = 4
  • BrickletOLED64x48.FUNCTION_WRITE_LINE = 6
public void setResponseExpectedAll(boolean responseExpected)

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

public BrickletOLED64x48.Identity getIdentity()

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.

The returned object has the public member variables String uid, String connectedUid, char position, short[] hardwareVersion, short[] firmwareVersion and int deviceIdentifier.

Constants

public static final int BrickletOLED64x48.DEVICE_IDENTIFIER

This constant is used to identify a OLED 64x48 Bricklet.

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

public static final String BrickletOLED64x48.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a OLED 64x48 Bricklet.