..
 #############################################################
 # This file was automatically generated on 2015-05-08.      #
 #                                                           #
 # If you have a bugfix for this file and want to commit it, #
 # please fix the bug in the generator. You can find a link  #
 # to the generators git repository on tinkerforge.com       #
 #############################################################


:breadcrumbs: <a href="../../index.html">Home</a> / <a href="../../index.html#software-java">Software</a> / Java - Hall Effect Bricklet

.. |device_identifier_constant| replace:: There is also a :ref:`constant <hall_effect_bricklet_java_constants>` for the device identifier of this Bricklet.

.. _hall_effect_bricklet_java:

Java - Hall Effect Bricklet
===========================

This is the description of the :ref:`Java API bindings <api_bindings_java>` for the :ref:`Hall Effect Bricklet <hall_effect_bricklet>`. General information and technical
specifications for the Hall Effect Bricklet are summarized in its :ref:`hardware description
<hall_effect_bricklet_description>`.

An :ref:`installation guide <api_bindings_java_install>` for the Java API
bindings is part of their general description.

.. _hall_effect_bricklet_java_examples:


Examples
--------

The example code below is `Public Domain (CC0 1.0)
<http://creativecommons.org/publicdomain/zero/1.0/>`__.

Simple
^^^^^^

`Download (ExampleSimple.java) <https://github.com/Tinkerforge/hall-effect-bricklet/raw/master/software/examples/java/ExampleSimple.java>`__

.. literalinclude:: HallEffect_Bricklet_Java_ExampleSimple.java
 :language: java
 :linenos:
 :tab-width: 4

Callback
^^^^^^^^

`Download (ExampleCallback.java) <https://github.com/Tinkerforge/hall-effect-bricklet/raw/master/software/examples/java/ExampleCallback.java>`__

.. literalinclude:: HallEffect_Bricklet_Java_ExampleCallback.java
 :language: java
 :linenos:
 :tab-width: 4

.. _hall_effect_bricklet_java_api:

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
^^^^^^^^^^^^^^^


.. java:function:: class BrickletHallEffect(String uid, IPConnection ipcon)

 Creates an object with the unique device ID ``uid``:

 .. code-block:: java

  BrickletHallEffect hallEffect = new BrickletHallEffect("YOUR_DEVICE_UID", ipcon);

 This object can then be used after the IP Connection is connected
 (see examples :ref:`above <hall_effect_bricklet_java_examples>`).


.. java:function:: public boolean BrickletHallEffect::getValue()

 Returns *true* if a magnetic field of 35 Gauss (3.5mT) or greater is detected.
 
.. java:function:: public long BrickletHallEffect::getEdgeCount(boolean resetCounter)

 Returns the current value of the edge counter. You can configure
 edge type (rising, falling, both) that is counted with
 :java:func:`setEdgeCountConfig() <BrickletHallEffect::setEdgeCountConfig>`.
 
 If you set the reset counter to *true*, the count is set back to 0
 directly after it is read.
 


Advanced Functions
^^^^^^^^^^^^^^^^^^

.. java:function:: public void BrickletHallEffect::setEdgeCountConfig(short edgeType, short debounce)

 The edge type parameter configures if rising edges, falling edges or 
 both are counted. Possible edge types are:
 
 * 0 = rising (default)
 * 1 = falling
 * 2 = both
 
 A magnetic field of 35 Gauss (3.5mT) or greater causes a falling edge and a
 magnetic field of 25 Gauss (2.5mT) or smaller causes a rising edge.
 
 If a magnet comes near the Bricklet the signal goes low (falling edge), if
 a magnet is removed from the vicinity the signal goes high (rising edge).
 
 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:
 
 * BrickletHallEffect.EDGE_TYPE_RISING = 0
 * BrickletHallEffect.EDGE_TYPE_FALLING = 1
 * BrickletHallEffect.EDGE_TYPE_BOTH = 2
 
.. java:function:: public BrickletHallEffect.EdgeCountConfig BrickletHallEffect::getEdgeCountConfig()

 Returns the edge type and debounce time as set by :java:func:`setEdgeCountConfig() <BrickletHallEffect::setEdgeCountConfig>`.
 
 The following constants are available for this function:
 
 * BrickletHallEffect.EDGE_TYPE_RISING = 0
 * BrickletHallEffect.EDGE_TYPE_FALLING = 1
 * BrickletHallEffect.EDGE_TYPE_BOTH = 2
 
 The returned object has the public member variables ``short edgeType`` and ``short debounce``.

.. java:function:: public short[] BrickletHallEffect::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.
 
.. java:function:: public boolean BrickletHallEffect::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
 :java:func:`setResponseExpected() <BrickletHallEffect::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 :java:func:`setResponseExpected() <BrickletHallEffect::setResponseExpected>`
 for the list of function ID constants available for this function.
 
.. java:function:: public void BrickletHallEffect::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:
 
 * BrickletHallEffect.FUNCTION_SET_EDGE_COUNT_CONFIG = 3
 * BrickletHallEffect.FUNCTION_SET_EDGE_INTERRUPT = 5
 * BrickletHallEffect.FUNCTION_SET_EDGE_COUNT_CALLBACK_PERIOD = 7
 
.. java:function:: public void BrickletHallEffect::setResponseExpectedAll(boolean responseExpected)

 Changes the response expected flag for all setter and listener configuration
 functions of this device at once.
 
.. java:function:: public BrickletHallEffect.Identity BrickletHallEffect::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 :ref:`here <device_identifier>`.
 |device_identifier_constant|
 
 The returned object has the public member variables ``String uid``, ``String connectedUid``, ``char position``, ``short[] hardwareVersion``, ``short[] firmwareVersion`` and ``int deviceIdentifier``.



Listener Configuration Functions
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

.. java:function:: public void BrickletHallEffect::setEdgeInterrupt(long edges)

 Sets the number of edges until an interrupt is invoked.
 
 If *edges* is set to n, an interrupt is invoked for every n-th detected edge.
 
 If *edges* is set to 0, the interrupt is disabled.
 
 Default value is 0.
 
.. java:function:: public long BrickletHallEffect::getEdgeInterrupt()

 Returns the edges as set by :java:func:`setEdgeInterrupt() <BrickletHallEffect::setEdgeInterrupt>`.
 
.. java:function:: public void BrickletHallEffect::setEdgeCountCallbackPeriod(long period)

 Sets the period in ms with which the :java:func:`EdgeCountListener <BrickletHallEffect.EdgeCountListener>` listener is triggered
 periodically. A value of 0 turns the listener off.
 
 :java:func:`EdgeCountListener <BrickletHallEffect.EdgeCountListener>` is only triggered if the edge count has changed since the
 last triggering.
 
 The default value is 0.
 
.. java:function:: public long BrickletHallEffect::getEdgeCountCallbackPeriod()

 Returns the period as set by :java:func:`setEdgeCountCallbackPeriod() <BrickletHallEffect::setEdgeCountCallbackPeriod>`.
 


.. _hall_effect_bricklet_java_callbacks:

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:

.. code-block:: java

    device.addExampleListener(new BrickletHallEffect.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.


.. java:function:: public class BrickletHallEffect.EdgeCountListener()

 This listener can be added with the ``addEdgeCountListener()`` function.
 An added listener can be removed with the ``removeEdgeCountListener()`` function.

 .. java:function:: public void edgeCount(long count, boolean value)
  :noindex:


  This listener is triggered periodically with the period that is set by
  :java:func:`setEdgeCountCallbackPeriod() <BrickletHallEffect::setEdgeCountCallbackPeriod>`. The parameters are the
  current count and the current value (see :java:func:`getValue() <BrickletHallEffect::getValue>` and :java:func:`getEdgeCount() <BrickletHallEffect::getEdgeCount>`).
  
  :java:func:`EdgeCountListener <BrickletHallEffect.EdgeCountListener>` is only triggered if the count or value changed since the
  last triggering.
  


.. _hall_effect_bricklet_java_constants:

Constants
^^^^^^^^^

.. java:member:: public static final int BrickletHallEffect.DEVICE_IDENTIFIER

 This constant is used to identify a Hall Effect Bricklet.

 The :java:func:`getIdentity() <BrickletHallEffect::getIdentity>` function and the
 :java:func:`EnumerateListener <IPConnection.EnumerateListener>`
 listener of the IP Connection have a ``deviceIdentifier`` parameter to specify
 the Brick's or Bricklet's type.

