MATLAB/Octave - Line Bricklet¶

Simple (MATLAB)¶

Download (matlab_example_simple.m)

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function matlab_example_simple()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletLine;

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

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

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

    % Get current reflectivity
    reflectivity = l.getReflectivity();
    fprintf('Reflectivity: %i\n', reflectivity);

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

Callback (MATLAB)¶

Download (matlab_example_callback.m)

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function matlab_example_callback()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletLine;

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

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

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

    % Register reflectivity callback to function cb_reflectivity
    set(l, 'ReflectivityCallback', @(h, e) cb_reflectivity(e));

    % Set period for reflectivity callback to 1s (1000ms)
    % Note: The reflectivity callback is only called every second
    %       if the reflectivity has changed since the last call!
    l.setReflectivityCallbackPeriod(1000);

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

% Callback function for reflectivity callback
function cb_reflectivity(e)
    fprintf('Reflectivity: %i\n', e.reflectivity);
end

Threshold (MATLAB)¶

Download (matlab_example_threshold.m)

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function matlab_example_threshold()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletLine;

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

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

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

    % Get threshold callbacks with a debounce time of 1 second (1000ms)
    l.setDebouncePeriod(1000);

    % Register reflectivity reached callback to function cb_reflectivity_reached
    set(l, 'ReflectivityReachedCallback', @(h, e) cb_reflectivity_reached(e));

    % Configure threshold for reflectivity "greater than 2000"
    l.setReflectivityCallbackThreshold('>', 2000, 0);

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

% Callback function for reflectivity reached callback
function cb_reflectivity_reached(e)
    fprintf('Reflectivity: %i\n', e.reflectivity);
end

Simple (Octave)¶

Download (octave_example_simple.m)

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function octave_example_simple()
    more off;

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

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

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

    % Get current reflectivity
    reflectivity = l.getReflectivity();
    fprintf("Reflectivity: %d\n", reflectivity);

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

Callback (Octave)¶

Download (octave_example_callback.m)

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function octave_example_callback()
    more off;

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

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

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

    % Register reflectivity callback to function cb_reflectivity
    l.addReflectivityCallback(@cb_reflectivity);

    % Set period for reflectivity callback to 1s (1000ms)
    % Note: The reflectivity callback is only called every second
    %       if the reflectivity has changed since the last call!
    l.setReflectivityCallbackPeriod(1000);

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

% Callback function for reflectivity callback
function cb_reflectivity(e)
    fprintf("Reflectivity: %d\n", e.reflectivity);
end

Threshold (Octave)¶

Download (octave_example_threshold.m)

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function octave_example_threshold()
    more off;

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

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

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

    % Get threshold callbacks with a debounce time of 1 second (1000ms)
    l.setDebouncePeriod(1000);

    % Register reflectivity reached callback to function cb_reflectivity_reached
    l.addReflectivityReachedCallback(@cb_reflectivity_reached);

    % Configure threshold for reflectivity "greater than 2000"
    l.setReflectivityCallbackThreshold(">", 2000, 0);

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

% Callback function for reflectivity reached callback
function cb_reflectivity_reached(e)
    fprintf("Reflectivity: %d\n", e.reflectivity);
end

Basic Functions¶

class BrickletLine(String uid, IPConnection ipcon)¶

Parameters:	uid – Type: String ipcon – Type: IPConnection
Returns:	line – Type: BrickletLine

Creates an object with the unique device ID uid.

In MATLAB:

import com.tinkerforge.BrickletLine;

line = BrickletLine('YOUR_DEVICE_UID', ipcon);

In Octave:

line = java_new("com.tinkerforge.BrickletLine", "YOUR_DEVICE_UID", ipcon);

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

int BrickletLine.getReflectivity()¶

Returns:	reflectivity – Type: int, Range: [0 to 212 - 1]

Returns the currently measured reflectivity. The reflectivity is a value between 0 (not reflective) and 4095 (very reflective).

Usually black has a low reflectivity while white has a high reflectivity.

If you want to get the reflectivity periodically, it is recommended to use the ReflectivityCallback callback and set the period with setReflectivityCallbackPeriod().

Advanced Functions¶

BrickletLine.Identity BrickletLine.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.

Callback Configuration Functions¶

void BrickletLine.setReflectivityCallbackPeriod(long period)¶

Parameters:	period – Type: long, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Sets the period with which the ReflectivityCallback callback is triggered periodically. A value of 0 turns the callback off.

The ReflectivityCallback callback is only triggered if the reflectivity has changed since the last triggering.

long BrickletLine.getReflectivityCallbackPeriod()¶

Returns:	period – Type: long, Unit: 1 ms, Range: [0 to 232 - 1], Default: 0

Returns the period as set by setReflectivityCallbackPeriod().

void BrickletLine.setReflectivityCallbackThreshold(char option, int min, int max)¶

Parameters:	option – Type: char, Range: See constants, Default: 'x' min – Type: int, Range: [0 to 216 - 1], Default: 0 max – Type: int, Range: [0 to 216 - 1], Default: 0

Sets the thresholds for the ReflectivityReachedCallback callback.

The following options are possible:

Option	Description
'x'	Callback is turned off
'o'	Callback is triggered when the reflectivity is outside the min and max values
'i'	Callback is triggered when the reflectivity is inside the min and max values
'<'	Callback is triggered when the reflectivity is smaller than the min value (max is ignored)
'>'	Callback is triggered when the reflectivity is greater than the min value (max is ignored)

The following constants are available for this function:

For option:

• BrickletLine.THRESHOLD_OPTION_OFF = 'x'
• BrickletLine.THRESHOLD_OPTION_OUTSIDE = 'o'
• BrickletLine.THRESHOLD_OPTION_INSIDE = 'i'
• BrickletLine.THRESHOLD_OPTION_SMALLER = '<'
• BrickletLine.THRESHOLD_OPTION_GREATER = '>'

BrickletLine.ReflectivityCallbackThreshold BrickletLine.getReflectivityCallbackThreshold()¶

Return Object:	option – Type: char, Range: See constants, Default: 'x' min – Type: int, Range: [0 to 216 - 1], Default: 0 max – Type: int, Range: [0 to 216 - 1], Default: 0

Returns the threshold as set by setReflectivityCallbackThreshold().

The following constants are available for this function:

For option:

• BrickletLine.THRESHOLD_OPTION_OFF = 'x'
• BrickletLine.THRESHOLD_OPTION_OUTSIDE = 'o'
• BrickletLine.THRESHOLD_OPTION_INSIDE = 'i'
• BrickletLine.THRESHOLD_OPTION_SMALLER = '<'
• BrickletLine.THRESHOLD_OPTION_GREATER = '>'

void BrickletLine.setDebouncePeriod(long debounce)¶

Parameters:	debounce – Type: long, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Sets the period with which the threshold callback

• ReflectivityReachedCallback

is triggered, if the threshold

• setReflectivityCallbackThreshold()

keeps being reached.

long BrickletLine.getDebouncePeriod()¶

Returns:	debounce – Type: long, Unit: 1 ms, Range: [0 to 232 - 1], Default: 100

Returns the debounce period as set by setDebouncePeriod().

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.

callback BrickletLine.ReflectivityCallback¶

Event Object:	reflectivity – Type: int, Range: [0 to 212 - 1]

This callback is triggered periodically with the period that is set by setReflectivityCallbackPeriod(). The parameter is the reflectivity of the sensor.

The ReflectivityCallback callback is only triggered if the reflectivity has changed since the last triggering.

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 addReflectivityCallback() function. An added callback function can be removed with the removeReflectivityCallback() function.

callback BrickletLine.ReflectivityReachedCallback¶

Event Object:	reflectivity – Type: int, Range: [0 to 212 - 1]

This callback is triggered when the threshold as set by setReflectivityCallbackThreshold() is reached. The parameter is the reflectivity of the sensor.

If the threshold keeps being reached, the callback is triggered periodically with the period as set by setDebouncePeriod().

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 addReflectivityReachedCallback() function. An added callback function can be removed with the removeReflectivityReachedCallback() 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[] BrickletLine.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 BrickletLine.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:

• BrickletLine.FUNCTION_SET_REFLECTIVITY_CALLBACK_PERIOD = 2
• BrickletLine.FUNCTION_SET_REFLECTIVITY_CALLBACK_THRESHOLD = 4
• BrickletLine.FUNCTION_SET_DEBOUNCE_PERIOD = 6

void BrickletLine.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:

• BrickletLine.FUNCTION_SET_REFLECTIVITY_CALLBACK_PERIOD = 2
• BrickletLine.FUNCTION_SET_REFLECTIVITY_CALLBACK_THRESHOLD = 4
• BrickletLine.FUNCTION_SET_DEBOUNCE_PERIOD = 6

void BrickletLine.setResponseExpectedAll(boolean responseExpected)¶

Parameters:	responseExpected – Type: boolean

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

Constants¶

int BrickletLine.DEVICE_IDENTIFIER¶

This constant is used to identify a Line 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 BrickletLine.DEVICE_DISPLAY_NAME¶

This constant represents the human readable name of a Line Bricklet.