MATLAB/Octave - Industrial Digital In 4 Bricklet

This is the description of the MATLAB/Octave API bindings for the Industrial Digital In 4 Bricklet. General information and technical specifications for the Industrial Digital In 4 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).

Simple (MATLAB)

Download (matlab_example_simple.m)

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function matlab_example_simple()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletIndustrialDigitalIn4;

    HOST = 'localhost';
    PORT = 4223;
    UID = 'XYZ'; % Change XYZ to the UID of your Industrial Digital In 4 Bricklet

    ipcon = IPConnection(); % Create IP connection
    idi4 = handle(BrickletIndustrialDigitalIn4(UID, ipcon), 'CallbackProperties'); % Create device object

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

    % Get current value as bitmask
    valueMask = idi4.getValue();
    fprintf('Value Mask: %s\n', dec2bin(valueMask));

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

Interrupt (MATLAB)

Download (matlab_example_interrupt.m)

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function matlab_example_interrupt()
    import com.tinkerforge.IPConnection;
    import com.tinkerforge.BrickletIndustrialDigitalIn4;

    HOST = 'localhost';
    PORT = 4223;
    UID = 'XYZ'; % Change XYZ to the UID of your Industrial Digital In 4 Bricklet

    ipcon = IPConnection(); % Create IP connection
    idi4 = handle(BrickletIndustrialDigitalIn4(UID, ipcon), 'CallbackProperties'); % Create device object

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

    % Register interrupt callback to function cb_interrupt
    set(idi4, 'InterruptCallback', @(h, e) cb_interrupt(e));

    % Enable interrupt on pin 0
    idi4.setInterrupt(bitshift(1, 0));

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

% Callback function for interrupt callback
function cb_interrupt(e)
    fprintf('Interrupt Mask: %s\n', dec2bin(e.interruptMask));
    fprintf('Value Mask: %s\n', dec2bin(e.valueMask));
    fprintf('\n');
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 Industrial Digital In 4 Bricklet

    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
    idi4 = javaObject("com.tinkerforge.BrickletIndustrialDigitalIn4", UID, ipcon); % Create device object

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

    % Get current value as bitmask
    valueMask = idi4.getValue();
    fprintf("Value Mask: %s\n", dec2bin(valueMask));

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

Interrupt (Octave)

Download (octave_example_interrupt.m)

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function octave_example_interrupt()
    more off;

    HOST = "localhost";
    PORT = 4223;
    UID = "XYZ"; % Change XYZ to the UID of your Industrial Digital In 4 Bricklet

    ipcon = javaObject("com.tinkerforge.IPConnection"); % Create IP connection
    idi4 = javaObject("com.tinkerforge.BrickletIndustrialDigitalIn4", UID, ipcon); % Create device object

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

    % Register interrupt callback to function cb_interrupt
    idi4.addInterruptCallback(@cb_interrupt);

    % Enable interrupt on pin 0
    idi4.setInterrupt(bitshift(1, 0));

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

% Callback function for interrupt callback
function cb_interrupt(e)
    fprintf("Interrupt Mask: %s\n", dec2bin(e.interruptMask));
    fprintf("Value Mask: %s\n", dec2bin(e.valueMask));
    fprintf("\n");
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 BrickletIndustrialDigitalIn4(String uid, IPConnection ipcon)

Creates an object with the unique device ID uid.

In MATLAB:

import com.tinkerforge.BrickletIndustrialDigitalIn4;

industrialDigitalIn4 = BrickletIndustrialDigitalIn4('YOUR_DEVICE_UID', ipcon);

In Octave:

industrialDigitalIn4 = java_new("com.tinkerforge.BrickletIndustrialDigitalIn4", "YOUR_DEVICE_UID", ipcon);

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

public int getValue()

Returns the input value with a bitmask. The bitmask is 16bit long, true refers to high and false refers to low.

For example: The value 3 or 0b0011 means that pins 0-1 are high and the other pins are low.

If no groups are used (see setGroup()), the pins correspond to the markings on the IndustrialDigital In 4 Bricklet.

If groups are used, the pins correspond to the element in the group. Element 1 in the group will get pins 0-3, element 2 pins 4-7, element 3 pins 8-11 and element 4 pins 12-15.

public long getEdgeCount(short pin, boolean resetCounter)

Returns the current value of the edge counter for the selected pin. You can configure the edges that are counted with setEdgeCountConfig().

If you set the reset counter to true, the count is set back to 0 directly after it is read.

New in version 2.0.1 (Plugin).

Advanced Functions

public void setGroup(char[] group)

Sets a group of Digital In 4 Bricklets that should work together. You can find Bricklets that can be grouped together with getAvailableForGroup().

The group consists of 4 elements. Element 1 in the group will get pins 0-3, element 2 pins 4-7, element 3 pins 8-11 and element 4 pins 12-15.

Each element can either be one of the ports ('a' to 'd') or 'n' if it should not be used.

For example: If you have two Digital In 4 Bricklets connected to port A and port B respectively, you could call with ['a', 'b', 'n', 'n'].

Now the pins on the Digital In 4 on port A are assigned to 0-3 and the pins on the Digital In 4 on port B are assigned to 4-7. It is now possible to call getValue() and read out two Bricklets at the same time.

Changing the group configuration resets all edge counter configurations and values.

public char[] getGroup()

Returns the group as set by setGroup()

public short getAvailableForGroup()

Returns a bitmask of ports that are available for grouping. For example the value 5 or 0b0101 means: Port A and port C are connected to Bricklets that can be grouped together.

public void setEdgeCountConfig(int selectionMask, short edgeType, short debounce)

Configures the edge counter for the selected pins. A bitmask of 9 or 0b1001 will enable the edge counter for pins 0 and 3.

The edge type parameter configures if rising edges, falling edges or both are counted if the pin is configured for input. Possible edge types are:

  • 0 = rising (default)
  • 1 = falling
  • 2 = both

The debounce time is given in ms.

Configuring an edge counter resets its value to 0.

If you don't know what any of this means, just leave it at default. The default configuration is very likely OK for you.

Default values: 0 (edge type) and 100ms (debounce time)

The following constants are available for this function:

  • BrickletIndustrialDigitalIn4.EDGE_TYPE_RISING = 0
  • BrickletIndustrialDigitalIn4.EDGE_TYPE_FALLING = 1
  • BrickletIndustrialDigitalIn4.EDGE_TYPE_BOTH = 2

New in version 2.0.1 (Plugin).

public BrickletIndustrialDigitalIn4.EdgeCountConfig getEdgeCountConfig(short pin)

Returns the edge type and debounce time for the selected pin as set by setEdgeCountConfig().

The following constants are available for this function:

  • BrickletIndustrialDigitalIn4.EDGE_TYPE_RISING = 0
  • BrickletIndustrialDigitalIn4.EDGE_TYPE_FALLING = 1
  • BrickletIndustrialDigitalIn4.EDGE_TYPE_BOTH = 2

New in version 2.0.1 (Plugin).

The returned object has the public member variables short edgeType and short debounce.

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:

  • BrickletIndustrialDigitalIn4.FUNCTION_SET_GROUP = 2
  • BrickletIndustrialDigitalIn4.FUNCTION_SET_DEBOUNCE_PERIOD = 5
  • BrickletIndustrialDigitalIn4.FUNCTION_SET_INTERRUPT = 7
  • BrickletIndustrialDigitalIn4.FUNCTION_SET_EDGE_COUNT_CONFIG = 11
public void setResponseExpectedAll(boolean responseExpected)

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

public BrickletIndustrialDigitalIn4.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.

Callback Configuration Functions

public void setDebouncePeriod(long debounce)

Sets the debounce period of the InterruptCallback callback in ms.

For example: If you set this value to 100, you will get the interrupt maximal every 100ms. This is necessary if something that bounces is connected to the Digital In 4 Bricklet, such as a button.

The default value is 100.

public long getDebouncePeriod()

Returns the debounce period as set by setDebouncePeriod().

public void setInterrupt(int interruptMask)

Sets the pins on which an interrupt is activated with a bitmask. Interrupts are triggered on changes of the voltage level of the pin, i.e. changes from high to low and low to high.

For example: An interrupt bitmask of 9 or 0b1001 will enable the interrupt for pins 0 and 3.

The interrupts use the grouping as set by setGroup().

The interrupt is delivered with the InterruptCallback callback.

public int getInterrupt()

Returns the interrupt bitmask as set by setInterrupt().

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.

Note

Using callbacks for recurring events is always preferred compared to using getters. It will use less USB bandwidth and the latency will be a lot better, since there is no round trip time.

public callback BrickletIndustrialDigitalIn4.InterruptCallback
Parameters:
  • interruptMask -- int
  • valueMask -- int

This callback is triggered whenever a change of the voltage level is detected on pins where the interrupt was activated with setInterrupt().

The values are a bitmask that specifies which interrupts occurred and the current value bitmask.

For example:

  • (1, 1) or (0b0001, 0b0001) means that an interrupt on pin 0 occurred and currently pin 0 is high and pins 1-3 are low.
  • (9, 14) or (0b1001, 0b1110) means that interrupts on pins 0 and 3 occurred and currently pin 0 is low and pins 1-3 are high.

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 addInterruptCallback() function. An added callback function can be removed with the removeInterruptCallback() function.

Constants

public static final int BrickletIndustrialDigitalIn4.DEVICE_IDENTIFIER

This constant is used to identify a Industrial Digital In 4 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.

public static final String BrickletIndustrialDigitalIn4.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Industrial Digital In 4 Bricklet.