Java - Industrial Digital In 4 Bricklet

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

Examples

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

Simple

Download (ExampleSimple.java)

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import com.tinkerforge.BrickletIndustrialDigitalIn4;
import com.tinkerforge.IPConnection;

public class ExampleSimple {
    private static final String HOST = "localhost";
    private static final int PORT = 4223;
    private static final String UID = "xyz"; // Change to your UID

    // 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
        BrickletIndustrialDigitalIn4 idi4 =
          new BrickletIndustrialDigitalIn4(UID, ipcon); // Create device object

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

        // Read out values as bitmask
        int value = idi4.getValue();
        System.out.println("value: " + value);

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

Interrupt

Download (ExampleInterrupt.java)

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import com.tinkerforge.BrickletIndustrialDigitalIn4;
import com.tinkerforge.IPConnection;

public class ExampleInterrupt {
    private static final String HOST = "localhost";
    private static final int PORT = 4223;
    private static final String UID = "xyz"; // Change to your UID
    
    // 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
        BrickletIndustrialDigitalIn4 idi4 =
          new BrickletIndustrialDigitalIn4(UID, ipcon); // Create device object

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

        // Add and implement listener for interrupt (called if pin 0 changes)
        idi4.addInterruptListener(new BrickletIndustrialDigitalIn4.InterruptListener() {
            public void interrupt(int interruptMask, int valueMask) {
                System.out.println("Interrupt by: " + Integer.toBinaryString(interruptMask));
                System.out.println("Value: " + Integer.toBinaryString(valueMask));
            }
        });

        // Enable interrupt on pin 0
        idi4.setInterrupt(1 << 0);

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

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 BrickletIndustrialDigitalIn4(String uid, IPConnection ipcon)

Creates an object with the unique device ID uid:

BrickletIndustrialDigitalIn4 industrialDigitalIn4 = new 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 Digital 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 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 and listeners it is always disabled.

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 listener 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.

Listener Configuration Functions

public void setDebouncePeriod(long debounce)

Sets the debounce period of the InterruptListener listener 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 listener InterruptListener.

public int getInterrupt()

Returns the interrupt bitmask as set by setInterrupt().

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 BrickletIndustrialDigitalIn4.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.

Note

Using listeners 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 class BrickletIndustrialDigitalIn4.InterruptListener()

This listener can be added with the addInterruptListener() function. An added listener can be removed with the removeInterruptListener() function.

public void interrupt(int interruptMask, int valueMask)

This listener 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.

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 EnumerateListener listener of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

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