JavaScript - OLED 64x48 Bricklet

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

Examples

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

Hello World (Node.js)

Download (ExampleHelloWorld.js)

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var Tinkerforge = require('tinkerforge');

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

var ipcon = new Tinkerforge.IPConnection(); // Create IP connection
var oled = new Tinkerforge.BrickletOLED64x48(UID, ipcon); // Create device object

ipcon.connect(HOST, PORT,
    function (error) {
        console.log('Error: ' + error);
    }
); // Connect to brickd
// Don't use device before ipcon is connected

ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
    function (connectReason) {
        // Clear display
        oled.clearDisplay();

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

console.log('Press key to exit');
process.stdin.on('data',
    function (data) {
        ipcon.disconnect();
        process.exit(0);
    }
);

Pixel Matrix (Node.js)

Download (ExamplePixelMatrix.js)

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var Tinkerforge = require('tinkerforge');

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

var ipcon = new Tinkerforge.IPConnection(); // Create IP connection
var oled = new Tinkerforge.BrickletOLED64x48(UID, ipcon); // Create device object

function drawMatrix(oled, pixels) {
    column = [];

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

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

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

            column[i][j] = page;
        }
    }

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

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

ipcon.connect(HOST, PORT,
    function (error) {
        console.log('Error: ' + error);
    }
); // Connect to brickd
// Don't use device before ipcon is connected

ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
    function (connectReason) {
        // Clear display
        oled.clearDisplay();

        // Draw checkerboard pattern
        var pixelMatrix = [];
        for (var h = 0; h < SCREEN_HEIGHT; h++) {
            pixelMatrix[h] = [];
            for (var w = 0; w < SCREEN_WIDTH; w++) {
                pixelMatrix[h][w] = Math.floor(h / 8) % 2 == Math.floor(w / 8) % 2;
            }
        }

        drawMatrix(oled, pixelMatrix);
    }
);

console.log('Press key to exit');
process.stdin.on('data',
    function (data) {
        ipcon.disconnect();
        process.exit(0);
    }
);

Scribble (Node.js)

Download (ExampleScribble.js)

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var Tinkerforge = require('tinkerforge');
var GM = require('gm'); // FIXME: maybe use node-gd instead
var getPixels = require('get-pixels');

var HOST = 'localhost';
var PORT = 4223;
var UID = 'XYZ'; // Change to your UID
var WIDTH = 64;
var HEIGHT = 48;

var ipcon = new Tinkerforge.IPConnection(); // Create IP connection
var oled = new Tinkerforge.BrickletOLED64x48(UID, ipcon); // Create device object
var originX = WIDTH / 2;
var originY = HEIGHT / 2;
var length = HEIGHT / 2 - 2;
var angle = 0;

function drawImage(oled, image) {
    // FIXME: GraphicsMagick doesn't seem to have a way to access the individual
    // pixels. Convert to PNG and then used get-pixels to read the pixels back.
    // This is far from ideal, but better than nothing.
    image.toBuffer('PNG', function (err, buffer) {
        if (err) {
            console.log('toBuffer: ' + err);
            return;
        }

        getPixels(buffer, 'image/png', function(err, pixels) {
            if (err) {
                console.log('getPixels: ' + err);
                return;
            }

            column = [];

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

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

                    for (var k = 0; k < 8; k++) {
                        if (pixels.get(j, i*8 + k, 0) > 0) {
                            page |= 1 << k;
                        }
                    }

                    column[i][j] = page;
                }
            }

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

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

ipcon.connect(HOST, PORT,
    function (error) {
        console.log('Error: ' + error);
    }
); // Connect to brickd
// Don't use device before ipcon is connected

ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
    function (connectReason) {
        // Clear display
        oled.clearDisplay();

        // Draw rotating line
        function render() {
            // FIXME: Creating the image once and reusing it would be better, but
            // on the second call toBuffer() fails with "Stream yields empty buffer"
            var image = GM(WIDTH, HEIGHT, '#000');
            var radians = angle * Math.PI / 180;
            var x = Math.floor(originX + length * Math.cos(radians));
            var y = Math.floor(originY + length * Math.sin(radians));

            image.fill('#FFF').drawLine(originX, originY, x, y);

            drawImage(oled, image);

            angle++;
        }

        setInterval(render, 25);
    }
);

console.log('Press key to exit');
process.stdin.on('data',
    function (data) {
        ipcon.disconnect();
        process.exit(0);
    }
);

Hello World (HTML)

Download (ExampleHelloWorld.html), Test (ExampleHelloWorld.html)

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<!DOCTYPE html>
<html>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <head>
        <title>Tinkerforge | JavaScript Example</title>
    </head>
    <body>
        <div style="text-align:center;">
            <h1>OLED 64x48 Bricklet Hello World Example</h1>
            <p>
                <input value="localhost" id="host" type="text" size="20">:
                <input value="4280" id="port" type="text" size="5">,
                <input value="uid" id="uid" type="text" size="5">
                <input value="Start Example" id="start" type="button" onclick="startExample();">
            </p>
            <p>
                <textarea readonly id="text" cols="80" rows="24" style="resize:none;"
                          >Press "Start Example" to begin ...</textarea>
            </p>
        </div>
        <script src="./Tinkerforge.js" type='text/javascript'></script>
        <script type='text/javascript'>
            var ipcon;
            var textArea = document.getElementById("text");
            function startExample() {
                textArea.value = "";
                var HOST = document.getElementById("host").value;
                var PORT = parseInt(document.getElementById("port").value);
                var UID = document.getElementById("uid").value;
                if(ipcon !== undefined) {
                    ipcon.disconnect();
                }
                ipcon = new Tinkerforge.IPConnection(); // Create IP connection
                var oled = new Tinkerforge.BrickletOLED64x48(UID, ipcon); // Create device object
                ipcon.connect(HOST, PORT,
                    function(error) {
                        textArea.value += 'Error: ' + error + '\n';
                    }
                ); // Connect to brickd
                // Don't use device before ipcon is connected

                ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
                    function (connectReason) {
                        // Clear display
                        oled.clearDisplay();

                        // Write "Hello World" starting from upper left corner of the screen
                        oled.writeLine(0, 0, 'Hello World');
                    }
                );
            }
        </script>
    </body>
</html>

Pixel Matrix (HTML)

Download (ExamplePixelMatrix.html), Test (ExamplePixelMatrix.html)

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<!DOCTYPE html>
<html>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <head>
        <title>Tinkerforge | JavaScript Example</title>
    </head>
    <body>
        <div style="text-align:center;">
            <h1>OLED 64x48 Bricklet Pixel Matrix Example</h1>
            <p>
                <input value="localhost" id="host" type="text" size="20">:
                <input value="4280" id="port" type="text" size="5">,
                <input value="uid" id="uid" type="text" size="5">
                <input value="Start Example" id="start" type="button" onclick="startExample();">
            </p>
            <p>
                <textarea readonly id="text" cols="80" rows="24" style="resize:none;"
                          >Press "Start Example" to begin ...</textarea>
            </p>
        </div>
        <script src="./Tinkerforge.js" type='text/javascript'></script>
        <script type='text/javascript'>
            var ipcon;
            var textArea = document.getElementById("text");
            var SCREEN_WIDTH = 64;
            var SCREEN_HEIGHT = 48;

            function drawMatrix(oled, pixels) {
                column = [];
                for (var i = 0; i < SCREEN_HEIGHT/8; i++) {
                    column[i] = [];
                }
                for (var i = 0; i < SCREEN_HEIGHT/8; i++) {
                    for (var j = 0; j < SCREEN_WIDTH; j++) {
                        page = 0;

                        for (var k = 0; k < 8; k++) {
                            if (pixels[i*8 + k][j]) {
                                page |= 1 << k;
                            }
                        }
                        column[i][j] = page;
                    }
                }
                oled.newWindow(0, SCREEN_WIDTH-1, 0, 5)
                for (var i = 0; i < 6; i++) {
                    oled.write(column[i])
                }
            }
            function startExample() {
                textArea.value = "";
                var HOST = document.getElementById("host").value;
                var PORT = parseInt(document.getElementById("port").value);
                var UID = document.getElementById("uid").value;
                if(ipcon !== undefined) {
                    ipcon.disconnect();
                }
                ipcon = new Tinkerforge.IPConnection(); // Create IP connection
                var oled = new Tinkerforge.BrickletOLED64x48(UID, ipcon); // Create device object
                ipcon.connect(HOST, PORT,
                    function(error) {
                        textArea.value += 'Error: ' + error + '\n';
                    }
                ); // Connect to brickd
                // Don't use device before ipcon is connected

                ipcon.on(Tinkerforge.IPConnection.CALLBACK_CONNECTED,
                    function (connectReason) {
                        // Clear display
                        oled.clearDisplay();

                        // Draw checkerboard pattern
                        var pixelMatrix = [];
                        for (var h = 0; h < SCREEN_HEIGHT; h++) {
                            pixelMatrix[h] = [];
                            for (var w = 0; w < SCREEN_WIDTH; w++) {
                                pixelMatrix[h][w] = Math.floor(h / 8) % 2 == Math.floor(w / 8) % 2;
                            }
                        }

                        drawMatrix(oled, pixelMatrix);
                    }
                );
            }
        </script>
    </body>
</html>

API

Generally, every method of the JavaScript bindings can take two optional parameters, returnCallback and errorCallback. These are two user defined callback functions. The returnCallback is called with the return values as parameters, if the method returns something. The errorCallback is called with an error code in case of an error. The error code can be one of the following values:

  • IPConnection.ERROR_ALREADY_CONNECTED = 11
  • IPConnection.ERROR_NOT_CONNECTED = 12
  • IPConnection.ERROR_CONNECT_FAILED = 13
  • IPConnection.ERROR_INVALID_FUNCTION_ID = 21
  • IPConnection.ERROR_TIMEOUT = 31
  • IPConnection.ERROR_INVALID_PARAMETER = 41
  • IPConnection.ERROR_FUNCTION_NOT_SUPPORTED = 42
  • IPConnection.ERROR_UNKNOWN_ERROR = 43

The namespace for the JavaScript bindings is Tinkerforge.*.

Basic Functions

new BrickletOLED64x48(uid, ipcon)
Parameters:
  • uid -- string
  • ipcon -- IPConnection

Creates an object with the unique device ID uid:

var oled64x48 = new BrickletOLED64x48("YOUR_DEVICE_UID", ipcon);

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

BrickletOLED64x48.write(data[, returnCallback][, errorCallback])
Parameters:
  • data -- [int, int, ..61x.., int]
Callback:

undefined

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.

BrickletOLED64x48.newWindow(columnFrom, columnTo, rowFrom, rowTo[, returnCallback][, errorCallback])
Parameters:
  • columnFrom -- int
  • columnTo -- int
  • rowFrom -- int
  • rowTo -- int
Callback:

undefined

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.

BrickletOLED64x48.clearDisplay([returnCallback][, errorCallback])
Callback:undefined

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

BrickletOLED64x48.writeLine(line, position, text[, returnCallback][, errorCallback])
Parameters:
  • line -- int
  • position -- int
  • text -- string
Callback:

undefined

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

BrickletOLED64x48.setDisplayConfiguration(contrast, invert[, returnCallback][, errorCallback])
Parameters:
  • contrast -- int
  • invert -- boolean
Callback:

undefined

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.

BrickletOLED64x48.getDisplayConfiguration([returnCallback][, errorCallback])
Callback:
  • contrast -- int
  • invert -- boolean

Returns the configuration as set by setDisplayConfiguration().

BrickletOLED64x48.getAPIVersion()
Return type:[int, int, int]

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.

BrickletOLED64x48.getResponseExpected(functionId[, errorCallback])
Parameters:
  • functionId -- int
Return 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 send and errors are silently ignored, because they cannot be detected.

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

BrickletOLED64x48.setResponseExpected(functionId, responseExpected[, errorCallback])
Parameters:
  • functionId -- int
  • responseExpected -- 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 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
BrickletOLED64x48.setResponseExpectedAll(responseExpected)
Parameters:
  • responseExpected -- boolean

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

BrickletOLED64x48.getIdentity([returnCallback][, errorCallback])
Callback:
  • uid -- string
  • connectedUid -- string
  • position -- char
  • hardwareVersion -- [int, int, int]
  • firmwareVersion -- [int, int, int]
  • deviceIdentifier -- int

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.

Constants

BrickletOLED64x48.DEVICE_IDENTIFIER

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

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

BrickletOLED64x48.DEVICE_DISPLAY_NAME

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