Java - OLED 64x48 Bricklet

This is the description of the Java 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 Java API bindings is part of their general description.

Examples

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

Hello World

Download (ExampleHelloWorld.java)

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import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletOLED64x48;

public class ExampleHelloWorld {
    private static final String HOST = "localhost";
    private static final int PORT = 4223;

    // Change XYZ to the UID of your OLED 64x48 Bricklet
    private static final String UID = "XYZ";

    // Note: To make the example code cleaner we do not handle exceptions. Exceptions
    //       you might normally want to catch are described in the documentation
    public static void main(String args[]) throws Exception {
        IPConnection ipcon = new IPConnection(); // Create IP connection
        BrickletOLED64x48 oled = new 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((short)0, (short)0, "Hello World");

        System.out.println("Press key to exit"); System.in.read();
        ipcon.disconnect();
    }
}

Pixel Matrix

Download (ExamplePixelMatrix.java)

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import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletOLED64x48;

public class ExamplePixelMatrix {
    private static final String HOST = "localhost";
    private static final int PORT = 4223;

    // Change XYZ to the UID of your OLED 64x48 Bricklet
    private static final String UID = "XYZ";
    private static final short SCREEN_WIDTH = 64;
    private static final short SCREEN_HEIGHT = 48;

    static void drawMatrix(BrickletOLED64x48 oled, boolean[][] pixels) throws Exception {
        short[][] column = new short[6][SCREEN_WIDTH];
        short page = 0;
        short i, j, k;

        for (i = 0; i < SCREEN_HEIGHT/8; i++)
        {
            for (j = 0; j < SCREEN_WIDTH; j++)
            {
                page = 0;

                for (k = 0; k < 8; k++)
                {
                    if (pixels[(i*8)+k][j] == true)
                    {
                        page |= (short)(1 << k);
                    }
                }
                column[i][j] = page;
            }
        }

        oled.newWindow((short)0, (short)(SCREEN_WIDTH-1), (short)0, (short)5);

        for (i = 0; i < SCREEN_HEIGHT/8; i++)
        {
            oled.write(column[i]);
        }
    }

    // Note: To make the example code cleaner we do not handle exceptions. Exceptions
    //       you might normally want to catch are described in the documentation
    public static void main(String args[]) throws Exception {
        IPConnection ipcon = new IPConnection(); // Create IP connection
        BrickletOLED64x48 oled = new 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
        boolean[][] pixelMatrix = new boolean[SCREEN_HEIGHT][SCREEN_WIDTH];

        for (short h = 0; h < SCREEN_HEIGHT; h++) {
            for (short w = 0; w < SCREEN_WIDTH; w++) {
                pixelMatrix[h][w] = (h / 8) % 2 == (w / 8) % 2;
            }
        }

        drawMatrix(oled, pixelMatrix);

        System.out.println("Press key to exit"); System.in.read();
        ipcon.disconnect();
    }
}

Scribble

Download (ExampleScribble.java)

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import java.awt.Color;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletOLED64x48;

public class ExampleScribble {
    private static final String HOST = "localhost";
    private static final int PORT = 4223;
    private static final String UID = "XYZ"; // Change to your UID
    private static final short WIDTH = 64;
    private static final short HEIGHT = 48;

    static void drawImage(BrickletOLED64x48 oled, BufferedImage image) throws Exception {
        short[][] column = new short[6][WIDTH];
        short page = 0;
        short i, j, k;

        for (i = 0; i < HEIGHT/8; i++)
        {
            for (j = 0; j < WIDTH; j++)
            {
                page = 0;

                for (k = 0; k < 8; k++)
                {
                    if ((image.getRGB(j, (i*8)+k) & 0x00FFFFFF) > 0)
                    {
                        page |= (short)(1 << k);
                    }
                }
                column[i][j] = page;
            }
        }

        oled.newWindow((short)0, (short)(WIDTH-1), (short)0, (short)5);

        for (i = 0; i < HEIGHT/8; i++)
        {
            oled.write(column[i]);
        }
    }

    // Note: To make the example code cleaner we do not handle exceptions. Exceptions
    //       you might normally want to catch are described in the documentation
    public static void main(String args[]) throws Exception {
        IPConnection ipcon = new IPConnection(); // Create IP connection
        BrickletOLED64x48 oled = new 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 rotating line
        BufferedImage image = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_ARGB);
        int originX = WIDTH / 2;
        int originY = HEIGHT / 2;
        int length = HEIGHT / 2 - 2;
        int angle = 0;

        System.out.println("Press ctrl+c to exit");

        while (true) {
            double radians = Math.toRadians(angle);
            int x = (int)(originX + length * Math.cos(radians));
            int y = (int)(originY + length * Math.sin(radians));
            Graphics g = image.createGraphics();

            g.setColor(Color.black);
            g.fillRect(0, 0, WIDTH, HEIGHT);
            g.setColor(Color.white);
            g.drawLine(originX, originY, x, y);
            g.dispose();

            drawImage(oled, image);
            Thread.sleep(25);

            angle++;
        }
    }
}

API

Generally, every method of the Java 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 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:

BrickletOLED64x48 oled64x48 = new 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 listener 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 listener 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 listener 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 EnumerateListener listener 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.