Visual Basic .NET - Distance IR Bricklet

This is the description of the Visual Basic .NET API bindings for the Distance IR Bricklet. General information and technical specifications for the Distance IR 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)

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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 Distance IR Bricklet

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

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

        ' Get current distance
        Dim distance As Integer = dir.GetDistance()
        Console.WriteLine("Distance: " + (distance/10.0).ToString() + " cm")

        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 Distance IR Bricklet

    ' Callback subroutine for distance callback
    Sub DistanceCB(ByVal sender As BrickletDistanceIR, ByVal distance As Integer)
        Console.WriteLine("Distance: " + (distance/10.0).ToString() + " cm")
    End Sub

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

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

        ' Register distance callback to subroutine DistanceCB
        AddHandler dir.DistanceCallback, AddressOf DistanceCB

        ' Set period for distance callback to 0.2s (200ms)
        ' Note: The distance callback is only called every 0.2 seconds
        '       if the distance has changed since the last call!
        dir.SetDistanceCallbackPeriod(200)

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

Threshold

Download (ExampleThreshold.vb)

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Imports System
Imports Tinkerforge

Module ExampleThreshold
    Const HOST As String = "localhost"
    Const PORT As Integer = 4223
    Const UID As String = "XYZ" ' Change XYZ to the UID of your Distance IR Bricklet

    ' Callback subroutine for distance reached callback
    Sub DistanceReachedCB(ByVal sender As BrickletDistanceIR, ByVal distance As Integer)
        Console.WriteLine("Distance: " + (distance/10.0).ToString() + " cm")
    End Sub

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

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

        ' Get threshold callbacks with a debounce time of 10 seconds (10000ms)
        dir.SetDebouncePeriod(10000)

        ' Register distance reached callback to subroutine DistanceReachedCB
        AddHandler dir.DistanceReachedCallback, AddressOf DistanceReachedCB

        ' Configure threshold for distance "smaller than 30 cm"
        dir.SetDistanceCallbackThreshold("<"C, 30*10, 0)

        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 BrickletDistanceIR(ByVal uid As String, ByVal ipcon As IPConnection)

Creates an object with the unique device ID uid:

Dim distanceIR As New BrickletDistanceIR("YOUR_DEVICE_UID", ipcon)

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

Function BrickletDistanceIR.GetDistance() As Integer

Returns the distance measured by the sensor. The value is in mm and possible distance ranges are 40 to 300, 100 to 800 and 200 to 1500, depending on the selected IR sensor.

If you want to get the distance periodically, it is recommended to use the DistanceCallback callback and set the period with SetDistanceCallbackPeriod().

Advanced Functions

Function BrickletDistanceIR.GetAnalogValue() As Integer

Returns the value as read by a 12-bit analog-to-digital converter. The value is between 0 and 4095.

Note

The value returned by GetDistance() 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 BrickletDistanceIR.SetSamplingPoint(ByVal position As Byte, ByVal distance As Integer)

Sets a sampling point value to a specific position of the lookup table. The lookup table comprises 128 equidistant analog values with corresponding distances.

If you measure a distance of 50cm at the analog value 2048, you should call this function with (64, 5000). The utilized analog-to-digital converter has a resolution of 12 bit. With 128 sampling points on the whole range, this means that every sampling point has a size of 32 analog values. Thus the analog value 2048 has the corresponding sampling point 64 = 2048/32.

Sampling points are saved on the EEPROM of the Distance IR Bricklet and loaded again on startup.

Note

An easy way to calibrate the sampling points of the Distance IR Bricklet is implemented in the Brick Viewer. If you want to calibrate your Bricklet it is highly recommended to use this implementation.

Function BrickletDistanceIR.GetSamplingPoint(ByVal position As Byte) As Integer

Returns the distance to a sampling point position as set by SetSamplingPoint().

Function BrickletDistanceIR.GetAPIVersion() As Byte()

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.

Function BrickletDistanceIR.GetResponseExpected(ByVal functionId As Byte) As 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 send and errors are silently ignored, because they cannot be detected.

See SetResponseExpected() for the list of function ID constants available for this function.

Sub BrickletDistanceIR.SetResponseExpected(ByVal functionId As Byte, ByVal responseExpected As 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 send and errors are silently ignored, because they cannot be detected.

The following function ID constants are available for this function:

  • BrickletDistanceIR.FUNCTION_SET_SAMPLING_POINT = 3
  • BrickletDistanceIR.FUNCTION_SET_DISTANCE_CALLBACK_PERIOD = 5
  • BrickletDistanceIR.FUNCTION_SET_ANALOG_VALUE_CALLBACK_PERIOD = 7
  • BrickletDistanceIR.FUNCTION_SET_DISTANCE_CALLBACK_THRESHOLD = 9
  • BrickletDistanceIR.FUNCTION_SET_ANALOG_VALUE_CALLBACK_THRESHOLD = 11
  • BrickletDistanceIR.FUNCTION_SET_DEBOUNCE_PERIOD = 13
Sub BrickletDistanceIR.SetResponseExpectedAll(ByVal responseExpected As Boolean)

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

Sub BrickletDistanceIR.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)

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.

Callback Configuration Functions

Sub BrickletDistanceIR.SetDistanceCallbackPeriod(ByVal period As Long)

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

The DistanceCallback callback is only triggered if the distance has changed since the last triggering.

The default value is 0.

Function BrickletDistanceIR.GetDistanceCallbackPeriod() As Long

Returns the period as set by SetDistanceCallbackPeriod().

Sub BrickletDistanceIR.SetAnalogValueCallbackPeriod(ByVal period As Long)

Sets the period in ms 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.

The default value is 0.

Function BrickletDistanceIR.GetAnalogValueCallbackPeriod() As Long

Returns the period as set by SetAnalogValueCallbackPeriod().

Sub BrickletDistanceIR.SetDistanceCallbackThreshold(ByVal option As Char, ByVal min As Integer, ByVal max As Integer)

Sets the thresholds for the DistanceReachedCallback callback.

The following options are possible:

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

The default value is ('x', 0, 0).

The following constants are available for this function:

  • BrickletDistanceIR.THRESHOLD_OPTION_OFF = "x"C
  • BrickletDistanceIR.THRESHOLD_OPTION_OUTSIDE = "o"C
  • BrickletDistanceIR.THRESHOLD_OPTION_INSIDE = "i"C
  • BrickletDistanceIR.THRESHOLD_OPTION_SMALLER = "<"C
  • BrickletDistanceIR.THRESHOLD_OPTION_GREATER = ">"C
Sub BrickletDistanceIR.GetDistanceCallbackThreshold(ByRef option As Char, ByRef min As Integer, ByRef max As Integer)

Returns the threshold as set by SetDistanceCallbackThreshold().

The following constants are available for this function:

  • BrickletDistanceIR.THRESHOLD_OPTION_OFF = "x"C
  • BrickletDistanceIR.THRESHOLD_OPTION_OUTSIDE = "o"C
  • BrickletDistanceIR.THRESHOLD_OPTION_INSIDE = "i"C
  • BrickletDistanceIR.THRESHOLD_OPTION_SMALLER = "<"C
  • BrickletDistanceIR.THRESHOLD_OPTION_GREATER = ">"C
Sub BrickletDistanceIR.SetAnalogValueCallbackThreshold(ByVal option As Char, ByVal min As Integer, ByVal max As Integer)

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 default value is ('x', 0, 0).

The following constants are available for this function:

  • BrickletDistanceIR.THRESHOLD_OPTION_OFF = "x"C
  • BrickletDistanceIR.THRESHOLD_OPTION_OUTSIDE = "o"C
  • BrickletDistanceIR.THRESHOLD_OPTION_INSIDE = "i"C
  • BrickletDistanceIR.THRESHOLD_OPTION_SMALLER = "<"C
  • BrickletDistanceIR.THRESHOLD_OPTION_GREATER = ">"C
Sub BrickletDistanceIR.GetAnalogValueCallbackThreshold(ByRef option As Char, ByRef min As Integer, ByRef max As Integer)

Returns the threshold as set by SetAnalogValueCallbackThreshold().

The following constants are available for this function:

  • BrickletDistanceIR.THRESHOLD_OPTION_OFF = "x"C
  • BrickletDistanceIR.THRESHOLD_OPTION_OUTSIDE = "o"C
  • BrickletDistanceIR.THRESHOLD_OPTION_INSIDE = "i"C
  • BrickletDistanceIR.THRESHOLD_OPTION_SMALLER = "<"C
  • BrickletDistanceIR.THRESHOLD_OPTION_GREATER = ">"C
Sub BrickletDistanceIR.SetDebouncePeriod(ByVal debounce As Long)

Sets the period in ms with which the threshold callbacks

are triggered, if the thresholds

keep being reached.

The default value is 100.

Function BrickletDistanceIR.GetDebouncePeriod() As Long

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

AddHandler distanceIR.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 BrickletDistanceIR.DistanceCallback(ByVal sender As BrickletDistanceIR, ByVal distance As Integer)

This callback is triggered periodically with the period that is set by SetDistanceCallbackPeriod(). The parameter is the distance of the sensor.

The DistanceCallback callback is only triggered if the distance has changed since the last triggering.

Event BrickletDistanceIR.AnalogValueCallback(ByVal sender As BrickletDistanceIR, ByVal value As Integer)

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

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

Event BrickletDistanceIR.DistanceReachedCallback(ByVal sender As BrickletDistanceIR, ByVal distance As Integer)

This callback is triggered when the threshold as set by SetDistanceCallbackThreshold() is reached. The parameter is the distance of the sensor.

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

Event BrickletDistanceIR.AnalogValueReachedCallback(ByVal sender As BrickletDistanceIR, ByVal value As Integer)

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

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

Constants

Const BrickletDistanceIR.DEVICE_IDENTIFIER

This constant is used to identify a Distance IR Bricklet.

The GetIdentity() function and the EnumerateCallback callback of the IP Connection have a deviceIdentifier parameter to specify the Brick's or Bricklet's type.

Const BrickletDistanceIR.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Distance IR Bricklet.