Visual Basic .NET - Hall Effect Bricklet¶

Simple¶

Download (ExampleSimple.vb)

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Imports System
Imports Tinkerforge

Module ExampleSimple
    Const HOST As String = "localhost"
    Const PORT As Integer = 4223
    Const UID As String = "XYZ" ' Change XYZ to the UID of your Hall Effect Bricklet

    Sub Main()
        Dim ipcon As New IPConnection() ' Create IP connection
        Dim he As New BrickletHallEffect(UID, ipcon) ' Create device object

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

        ' Get current edge count without reset
        Dim count As Long = he.GetEdgeCount(False)
        Console.WriteLine("Count: " + count.ToString())

        Console.WriteLine("Press key to exit")
        Console.ReadLine()
        ipcon.Disconnect()
    End Sub
End Module

Callback¶

Download (ExampleCallback.vb)

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Imports System
Imports Tinkerforge

Module ExampleCallback
    Const HOST As String = "localhost"
    Const PORT As Integer = 4223
    Const UID As String = "XYZ" ' Change XYZ to the UID of your Hall Effect Bricklet

    ' Callback subroutine for edge count callback
    Sub EdgeCountCB(ByVal sender As BrickletHallEffect, ByVal count As Long, _
                    ByVal value As Boolean)
        Console.WriteLine("Count: " + count.ToString())
    End Sub

    Sub Main()
        Dim ipcon As New IPConnection() ' Create IP connection
        Dim he As New BrickletHallEffect(UID, ipcon) ' Create device object

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

        ' Register edge count callback to subroutine EdgeCountCB
        AddHandler he.EdgeCountCallback, AddressOf EdgeCountCB

        ' Set period for edge count callback to 0.05s (50ms)
        ' Note: The edge count callback is only called every 0.05 seconds
        '       if the edge count has changed since the last call!
        he.SetEdgeCountCallbackPeriod(50)

        Console.WriteLine("Press key to exit")
        Console.ReadLine()
        ipcon.Disconnect()
    End Sub
End Module

Basic Functions¶

Class BrickletHallEffect(ByVal uid As String, ByVal ipcon As IPConnection)¶

Creates an object with the unique device ID uid:

Dim hallEffect As New BrickletHallEffect("YOUR_DEVICE_UID", ipcon)

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

Function BrickletHallEffect.GetValue() As Boolean¶

Returns:	value – Type: Boolean

Returns true if a magnetic field of 3.5 millitesla or greater is detected.

Function BrickletHallEffect.GetEdgeCount(ByVal resetCounter As Boolean) As Long¶

Parameters:	resetCounter – Type: Boolean
Returns:	count – Type: Long, Range: [0 to 232 - 1]

Returns the current value of the edge counter. You can configure edge type (rising, falling, both) that is counted with SetEdgeCountConfig().

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

Advanced Functions¶

Sub BrickletHallEffect.SetEdgeCountConfig(ByVal edgeType As Byte, ByVal debounce As Byte)¶

Parameters:	edgeType – Type: Byte, Range: See constants, Default: 0 debounce – Type: Byte, Unit: 1 ms, Range: [0 to 255], Default: 100

The edge type parameter configures if rising edges, falling edges or both are counted. Possible edge types are:

• 0 = rising
• 1 = falling
• 2 = both

A magnetic field of 3.5 millitesla or greater causes a falling edge and a magnetic field of 2.5 millitesla 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).

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.

The following constants are available for this function:

For edgeType:

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

Sub BrickletHallEffect.GetEdgeCountConfig(ByRef edgeType As Byte, ByRef debounce As Byte)¶

Output Parameters:	edgeType – Type: Byte, Range: See constants, Default: 0 debounce – Type: Byte, Unit: 1 ms, Range: [0 to 255], Default: 100

Returns the edge type and debounce time as set by SetEdgeCountConfig().

The following constants are available for this function:

For edgeType:

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

Sub BrickletHallEffect.GetIdentity(ByRef uid As String, ByRef connectedUid As String, ByRef position As Char, ByRef hardwareVersion() As Byte, ByRef firmwareVersion() As Byte, ByRef deviceIdentifier As Integer)¶

Output Parameters:

uid – Type: String, Length: up to 8 connectedUid – Type: String, Length: up to 8 position – Type: Char, Range: ["a"C to "h"C, "z"C] hardwareVersion – Type: Byte Array, Length: 3 0: major – Type: Byte, Range: [0 to 255] 1: minor – Type: Byte, Range: [0 to 255] 2: revision – Type: Byte, Range: [0 to 255] firmwareVersion – Type: Byte Array, Length: 3 0: major – Type: Byte, Range: [0 to 255] 1: minor – Type: Byte, Range: [0 to 255] 2: revision – Type: Byte, Range: [0 to 255] deviceIdentifier – Type: Integer, 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¶

Sub BrickletHallEffect.SetEdgeInterrupt(ByVal edges As Long)¶

Parameters:	edges – Type: Long, Range: [0 to 232 - 1], Default: 0

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.

Function BrickletHallEffect.GetEdgeInterrupt() As Long¶

Returns:	edges – Type: Long, Range: [0 to 232 - 1], Default: 0

Returns the edges as set by SetEdgeInterrupt().

Sub BrickletHallEffect.SetEdgeCountCallbackPeriod(ByVal period As Long)¶

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

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

The EdgeCountCallback callback is only triggered if the edge count has changed since the last triggering.

Function BrickletHallEffect.GetEdgeCountCallbackPeriod() As Long¶

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

Returns the period as set by SetEdgeCountCallbackPeriod().

Callbacks¶

Callbacks can be registered to receive time critical or recurring data from the device. The registration is done by assigning a procedure to an callback property of the device object:

Sub MyCallback(ByVal sender As BrickletHallEffect, ByVal value As Short)
    Console.WriteLine("Value: {0}", value)
End Sub

AddHandler hallEffect.ExampleCallback, AddressOf MyCallback

The available callback property and their type of parameters are described below.

Event BrickletHallEffect.EdgeCountCallback(ByVal sender As BrickletHallEffect, ByVal count As Long, ByVal value As Boolean)¶

Callback Parameters:	sender – Type: BrickletHallEffect count – Type: Long, Range: [0 to 232 - 1] value – Type: Boolean

This callback is triggered periodically with the period that is set by SetEdgeCountCallbackPeriod(). The parameters are the current count and the current value (see GetValue() and GetEdgeCount()).

The EdgeCountCallback callback is only triggered if the count or value changed since the last triggering.

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.

Function BrickletHallEffect.GetAPIVersion() As Byte()¶

Output Parameters:	apiVersion – Type: Byte Array, Length: 3 0: major – Type: Byte, Range: [0 to 255] 1: minor – Type: Byte, Range: [0 to 255] 2: revision – Type: Byte, 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.

Function BrickletHallEffect.GetResponseExpected(ByVal functionId As Byte) As Boolean¶

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:

• BrickletHallEffect.FUNCTION_SET_EDGE_COUNT_CONFIG = 3
• BrickletHallEffect.FUNCTION_SET_EDGE_INTERRUPT = 5
• BrickletHallEffect.FUNCTION_SET_EDGE_COUNT_CALLBACK_PERIOD = 7

Sub BrickletHallEffect.SetResponseExpected(ByVal functionId As Byte, ByVal responseExpected As Boolean)¶

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:

• BrickletHallEffect.FUNCTION_SET_EDGE_COUNT_CONFIG = 3
• BrickletHallEffect.FUNCTION_SET_EDGE_INTERRUPT = 5
• BrickletHallEffect.FUNCTION_SET_EDGE_COUNT_CALLBACK_PERIOD = 7

Sub BrickletHallEffect.SetResponseExpectedAll(ByVal responseExpected As Boolean)¶

Parameters:	responseExpected – Type: Boolean

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

Constants¶

Const BrickletHallEffect.DEVICE_IDENTIFIER¶

This constant is used to identify a Hall Effect 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.

Const BrickletHallEffect.DEVICE_DISPLAY_NAME¶

This constant represents the human readable name of a Hall Effect Bricklet.