Java - Multi Touch Bricklet¶

Simple¶

Download (ExampleSimple.java)

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import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletMultiTouch;

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

    // Change XYZ to the UID of your Multi Touch 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
        BrickletMultiTouch mt = new BrickletMultiTouch(UID, ipcon); // Create device object

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

        // Get current touch state
        int state = mt.getTouchState(); // Can throw com.tinkerforge.TimeoutException
        String str = "";

        if((state & (1 << 12)) == (1 << 12)) {
            str += "In proximity, ";
        }

        if((state & 0xfff) == 0) {
            str += "No electrodes touched";
        } else {
            str += "Electrodes ";
            for(int i = 0; i < 12; i++) {
                if((state & (1 << i)) == (1 << i)) {
                    str += i + " ";
                }
            }
            str += "touched";
        }

        System.out.println(str);

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

Callback¶

Download (ExampleCallback.java)

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import com.tinkerforge.IPConnection;
import com.tinkerforge.BrickletMultiTouch;

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

    // Change XYZ to the UID of your Multi Touch 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
        BrickletMultiTouch mt = new BrickletMultiTouch(UID, ipcon); // Create device object

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

        // Add touch state listener
        mt.addTouchStateListener(new BrickletMultiTouch.TouchStateListener() {
            public void touchState(int state) {
                String str = "";

                if((state & (1 << 12)) == (1 << 12)) {
                    str += "In proximity, ";
                }

                if((state & 0xfff) == 0) {
                    str += "No electrodes touched";
                } else {
                    str += "Electrodes ";
                    for(int i = 0; i < 12; i++) {
                        if((state & (1 << i)) == (1 << i)) {
                            str += i + " ";
                        }
                    }
                    str += "touched";
                }

                System.out.println(str);
            }
        });

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

Basic Functions¶

class BrickletMultiTouch(String uid, IPConnection ipcon)¶

Parameters:	uid – Type: String ipcon – Type: IPConnection
Returns:	multiTouch – Type: BrickletMultiTouch

Creates an object with the unique device ID uid:

BrickletMultiTouch multiTouch = new BrickletMultiTouch("YOUR_DEVICE_UID", ipcon);

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

int BrickletMultiTouch.getTouchState()¶

Returns:	state – Type: int, Range: [0 to 213 - 1]

Returns the current touch state. The state is given as a bitfield.

Bits 0 to 11 represent the 12 electrodes and bit 12 represents the proximity.

If an electrode is touched, the corresponding bit is true. If a hand or similar is in proximity to the electrodes, bit 12 is true.

Example: The state 4103 = 0x1007 = 0b1000000000111 means that electrodes 0, 1 and 2 are touched and that something is in the proximity of the electrodes.

The proximity is activated with a distance of 1-2cm. An electrode is already counted as touched if a finger is nearly touching the electrode. This means that you can put a piece of paper or foil or similar on top of a electrode to build a touch panel with a professional look.

void BrickletMultiTouch.recalibrate()¶

Recalibrates the electrodes. Call this function whenever you changed or moved you electrodes.

void BrickletMultiTouch.setElectrodeConfig(int enabledElectrodes)¶

Parameters:	enabledElectrodes – Type: int, Range: [0 to 213 - 1], Default: 213 - 1

Enables/disables electrodes with a bitfield (see getTouchState()).

True enables the electrode, false disables the electrode. A disabled electrode will always return false as its state. If you don't need all electrodes you can disable the electrodes that are not needed.

It is recommended that you disable the proximity bit (bit 12) if the proximity feature is not needed. This will reduce the amount of traffic that is produced by the TouchStateListener listener.

Disabling electrodes will also reduce power consumption.

Default: 8191 = 0x1FFF = 0b1111111111111 (all electrodes and proximity feature enabled)

int BrickletMultiTouch.getElectrodeConfig()¶

Returns:	enabledElectrodes – Type: int, Range: [0 to 213 - 1], Default: 213 - 1

Returns the electrode configuration, as set by setElectrodeConfig().

void BrickletMultiTouch.setElectrodeSensitivity(short sensitivity)¶

Parameters:	sensitivity – Type: short, Range: [5 to 201], Default: 181

Sets the sensitivity of the electrodes. An electrode with a high sensitivity will register a touch earlier then an electrode with a low sensitivity.

If you build a big electrode you might need to decrease the sensitivity, since the area that can be charged will get bigger. If you want to be able to activate an electrode from further away you need to increase the sensitivity.

After a new sensitivity is set, you likely want to call recalibrate() to calibrate the electrodes with the newly defined sensitivity.

short BrickletMultiTouch.getElectrodeSensitivity()¶

Returns:	sensitivity – Type: short, Range: [5 to 201], Default: 181

Returns the current sensitivity, as set by setElectrodeSensitivity().

Advanced Functions¶

BrickletMultiTouch.Identity BrickletMultiTouch.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 0: major – Type: short, Range: [0 to 255] 1: minor – Type: short, Range: [0 to 255] 2: revision – Type: short, Range: [0 to 255] firmwareVersion – Type: short[], Length: 3 0: major – Type: short, Range: [0 to 255] 1: minor – Type: short, Range: [0 to 255] 2: 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.

Listeners¶

Listeners can be registered to receive time critical or recurring data from the device. The registration is done with add*Listener() functions of the device object.

The parameter is a listener class object, for example:

device.addExampleListener(new BrickletMultiTouch.ExampleListener() {
    public void property(int value) {
        System.out.println("Value: " + value);
    }
});

The available listener classes with inherent methods to be overwritten are described below. It is possible to add several listeners and to remove them with the corresponding remove*Listener() function.

class BrickletMultiTouch.TouchStateListener()¶

This listener can be added with the addTouchStateListener() function. An added listener can be removed with the removeTouchStateListener() function.

void touchState(int state)

Parameters:	state – Type: int, Range: [0 to 213 - 1]

Returns the current touch state, see getTouchState() for information about the state.

This listener is triggered every time the touch state changes.

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[] BrickletMultiTouch.getAPIVersion()¶

Return Object:	apiVersion – Type: short[], Length: 3 0: major – Type: short, Range: [0 to 255] 1: minor – Type: short, Range: [0 to 255] 2: 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 BrickletMultiTouch.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 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 sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For functionId:

• BrickletMultiTouch.FUNCTION_RECALIBRATE = 2
• BrickletMultiTouch.FUNCTION_SET_ELECTRODE_CONFIG = 3
• BrickletMultiTouch.FUNCTION_SET_ELECTRODE_SENSITIVITY = 6

void BrickletMultiTouch.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 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 sent and errors are silently ignored, because they cannot be detected.

The following constants are available for this function:

For functionId:

• BrickletMultiTouch.FUNCTION_RECALIBRATE = 2
• BrickletMultiTouch.FUNCTION_SET_ELECTRODE_CONFIG = 3
• BrickletMultiTouch.FUNCTION_SET_ELECTRODE_SENSITIVITY = 6

void BrickletMultiTouch.setResponseExpectedAll(boolean responseExpected)¶

Parameters:	responseExpected – Type: boolean

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

Constants¶

int BrickletMultiTouch.DEVICE_IDENTIFIER¶

This constant is used to identify a Multi Touch Bricklet.

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

String BrickletMultiTouch.DEVICE_DISPLAY_NAME¶

This constant represents the human readable name of a Multi Touch Bricklet.