Software / API Bindings / Visual Basic .NET / API Reference and Examples / Bricklets / Rotary Poti Bricklet

Visual Basic .NET - Rotary Poti Bricklet¶

This is the description of the Visual Basic .NET API bindings for the Rotary Poti Bricklet. General information and technical specifications for the Rotary Poti Bricklet are summarized in its hardware description.

An installation guide for the Visual Basic .NET API bindings is part of their general description.

Examples¶

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

Simple¶

Download (ExampleSimple.vb)

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 Rotary Poti Bricklet

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

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

        ' Get current position
        Dim position As Short = rp.GetPosition()
        Console.WriteLine("Position: " + position.ToString()) ' Range: -150 to 150

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

Callback¶

Download (ExampleCallback.vb)

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 Rotary Poti Bricklet

    ' Callback subroutine for position callback
    Sub PositionCB(ByVal sender As BrickletRotaryPoti, ByVal position As Short)
        Console.WriteLine("Position: " + position.ToString()) ' Range: -150 to 150
    End Sub

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

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

        ' Register position callback to subroutine PositionCB
        AddHandler rp.PositionCallback, AddressOf PositionCB

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

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

API¶

Since Visual Basic .NET does not support multiple return values directly, we use the ByRef keyword to return multiple values from a function.

All functions and procedures listed below are thread-safe.

Basic Functions¶

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

Creates an object with the unique device ID uid:

Dim rotaryPoti As New BrickletRotaryPoti("YOUR_DEVICE_UID", ipcon)

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

Function BrickletRotaryPoti.GetPosition() As Short¶

Returns:	position – Type: Short, Unit: 1 °, Range: [-150 to 150]

Returns the position of the rotary potentiometer. The value is between -150° (turned left) and 150° (turned right).

If you want to get the position periodically, it is recommended to use the PositionCallback callback and set the period with SetPositionCallbackPeriod().

Advanced Functions¶

Function BrickletRotaryPoti.GetAnalogValue() As Integer¶

Returns:	value – Type: Integer, Range: [0 to 2¹²]

Returns the value as read by a 12-bit analog-to-digital converter.

Note

The value returned by GetPosition() is averaged over several samples to yield less noise, while GetAnalogValue() gives back raw unfiltered analog values. The only reason to use GetAnalogValue() is, if you need the full resolution of the analog-to-digital converter.

If you want the analog value periodically, it is recommended to use the AnalogValueCallback callback and set the period with SetAnalogValueCallbackPeriod().

Sub BrickletRotaryPoti.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:

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]

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 BrickletRotaryPoti.SetPositionCallbackPeriod(ByVal period As Long)¶

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

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

The PositionCallback callback is only triggered if the position has changed since the last triggering.

Function BrickletRotaryPoti.GetPositionCallbackPeriod() As Long¶

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

Returns the period as set by SetPositionCallbackPeriod().

Sub BrickletRotaryPoti.SetAnalogValueCallbackPeriod(ByVal period As Long)¶

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

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

The AnalogValueCallback callback is only triggered if the analog value has changed since the last triggering.

Function BrickletRotaryPoti.GetAnalogValueCallbackPeriod() As Long¶

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

Returns the period as set by SetAnalogValueCallbackPeriod().

Sub BrickletRotaryPoti.SetPositionCallbackThreshold(ByVal option As Char, ByVal min As Short, ByVal max As Short)¶

Parameters:	option – Type: Char, Range: See constants, Default: "x"C min – Type: Short, Unit: 1 °, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0 max – Type: Short, Unit: 1 °, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0

Sets the thresholds for the PositionReachedCallback callback.

The following options are possible:

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

The following constants are available for this function:

For option:

BrickletRotaryPoti.THRESHOLD_OPTION_OFF = "x"C
BrickletRotaryPoti.THRESHOLD_OPTION_OUTSIDE = "o"C
BrickletRotaryPoti.THRESHOLD_OPTION_INSIDE = "i"C
BrickletRotaryPoti.THRESHOLD_OPTION_SMALLER = "<"C
BrickletRotaryPoti.THRESHOLD_OPTION_GREATER = ">"C

Sub BrickletRotaryPoti.GetPositionCallbackThreshold(ByRef option As Char, ByRef min As Short, ByRef max As Short)¶

Output Parameters:	option – Type: Char, Range: See constants, Default: "x"C min – Type: Short, Unit: 1 °, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0 max – Type: Short, Unit: 1 °, Range: [-2¹⁵ to 2¹⁵ - 1], Default: 0

Returns the threshold as set by SetPositionCallbackThreshold().

The following constants are available for this function:

For option:

BrickletRotaryPoti.THRESHOLD_OPTION_OFF = "x"C
BrickletRotaryPoti.THRESHOLD_OPTION_OUTSIDE = "o"C
BrickletRotaryPoti.THRESHOLD_OPTION_INSIDE = "i"C
BrickletRotaryPoti.THRESHOLD_OPTION_SMALLER = "<"C
BrickletRotaryPoti.THRESHOLD_OPTION_GREATER = ">"C

Sub BrickletRotaryPoti.SetAnalogValueCallbackThreshold(ByVal option As Char, ByVal min As Integer, ByVal max As Integer)¶

Parameters:	option – Type: Char, Range: See constants, Default: "x"C min – Type: Integer, Unit: 1 °, Range: [0 to 2¹⁶ - 1], Default: 0 max – Type: Integer, Unit: 1 °, Range: [0 to 2¹⁶ - 1], Default: 0

Sets the thresholds for the AnalogValueReachedCallback callback.

The following options are possible:

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

The following constants are available for this function:

For option:

BrickletRotaryPoti.THRESHOLD_OPTION_OFF = "x"C
BrickletRotaryPoti.THRESHOLD_OPTION_OUTSIDE = "o"C
BrickletRotaryPoti.THRESHOLD_OPTION_INSIDE = "i"C
BrickletRotaryPoti.THRESHOLD_OPTION_SMALLER = "<"C
BrickletRotaryPoti.THRESHOLD_OPTION_GREATER = ">"C

Sub BrickletRotaryPoti.GetAnalogValueCallbackThreshold(ByRef option As Char, ByRef min As Integer, ByRef max As Integer)¶

Output Parameters:	option – Type: Char, Range: See constants, Default: "x"C min – Type: Integer, Unit: 1 °, Range: [0 to 2¹⁶ - 1], Default: 0 max – Type: Integer, Unit: 1 °, Range: [0 to 2¹⁶ - 1], Default: 0

Returns the threshold as set by SetAnalogValueCallbackThreshold().

The following constants are available for this function:

For option:

BrickletRotaryPoti.THRESHOLD_OPTION_OFF = "x"C
BrickletRotaryPoti.THRESHOLD_OPTION_OUTSIDE = "o"C
BrickletRotaryPoti.THRESHOLD_OPTION_INSIDE = "i"C
BrickletRotaryPoti.THRESHOLD_OPTION_SMALLER = "<"C
BrickletRotaryPoti.THRESHOLD_OPTION_GREATER = ">"C

Sub BrickletRotaryPoti.SetDebouncePeriod(ByVal debounce As Long)¶

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

Sets the period with which the threshold callbacks

PositionReachedCallback,
AnalogValueReachedCallback

are triggered, if the thresholds

SetPositionCallbackThreshold(),
SetAnalogValueCallbackThreshold()

keep being reached.

Function BrickletRotaryPoti.GetDebouncePeriod() As Long¶

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 by assigning a procedure to an callback property of the device object:

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

AddHandler rotaryPoti.ExampleCallback, AddressOf MyCallback

The available callback property and their type of parameters 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.

Event BrickletRotaryPoti.PositionCallback(ByVal sender As BrickletRotaryPoti, ByVal position As Short)¶

Callback Parameters:	sender – Type: BrickletRotaryPoti position – Type: Short, Unit: 1 °, Range: [-150 to 150]

This callback is triggered periodically with the period that is set by SetPositionCallbackPeriod(). The parameter is the position of the rotary potentiometer.

The PositionCallback callback is only triggered if the position has changed since the last triggering.

Event BrickletRotaryPoti.AnalogValueCallback(ByVal sender As BrickletRotaryPoti, ByVal value As Integer)¶

Callback Parameters:	sender – Type: BrickletRotaryPoti value – Type: Integer, Range: [0 to 2¹²]

This callback is triggered periodically with the period that is set by SetAnalogValueCallbackPeriod(). The parameter is the analog value of the rotary potentiometer.

The AnalogValueCallback callback is only triggered if the position has changed since the last triggering.

Event BrickletRotaryPoti.PositionReachedCallback(ByVal sender As BrickletRotaryPoti, ByVal position As Short)¶

Callback Parameters:	sender – Type: BrickletRotaryPoti position – Type: Short, Unit: 1 °, Range: [-150 to 150]

This callback is triggered when the threshold as set by SetPositionCallbackThreshold() is reached. The parameter is the position of the rotary potentiometer.

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

Event BrickletRotaryPoti.AnalogValueReachedCallback(ByVal sender As BrickletRotaryPoti, ByVal value As Integer)¶

Callback Parameters:	sender – Type: BrickletRotaryPoti value – Type: Integer, Range: [0 to 2¹²]

This callback is triggered when the threshold as set by SetAnalogValueCallbackThreshold() is reached. The parameter is the analog value of the rotary potentiometer.

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

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 BrickletRotaryPoti.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 BrickletRotaryPoti.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:

BrickletRotaryPoti.FUNCTION_SET_POSITION_CALLBACK_PERIOD = 3
BrickletRotaryPoti.FUNCTION_SET_ANALOG_VALUE_CALLBACK_PERIOD = 5
BrickletRotaryPoti.FUNCTION_SET_POSITION_CALLBACK_THRESHOLD = 7
BrickletRotaryPoti.FUNCTION_SET_ANALOG_VALUE_CALLBACK_THRESHOLD = 9
BrickletRotaryPoti.FUNCTION_SET_DEBOUNCE_PERIOD = 11

Sub BrickletRotaryPoti.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.

The following constants are available for this function:

For functionId:

BrickletRotaryPoti.FUNCTION_SET_POSITION_CALLBACK_PERIOD = 3
BrickletRotaryPoti.FUNCTION_SET_ANALOG_VALUE_CALLBACK_PERIOD = 5
BrickletRotaryPoti.FUNCTION_SET_POSITION_CALLBACK_THRESHOLD = 7
BrickletRotaryPoti.FUNCTION_SET_ANALOG_VALUE_CALLBACK_THRESHOLD = 9
BrickletRotaryPoti.FUNCTION_SET_DEBOUNCE_PERIOD = 11

Sub BrickletRotaryPoti.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 BrickletRotaryPoti.DEVICE_IDENTIFIER¶

This constant is used to identify a Rotary Poti 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 BrickletRotaryPoti.DEVICE_DISPLAY_NAME¶: This constant represents the human readable name of a Rotary Poti Bricklet.