Visual Basic .NET - Thermocouple Bricklet

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

    Sub Main()
        Dim ipcon As New IPConnection() ' Create IP connection
        Dim t As New BrickletThermocouple(UID, ipcon) ' Create device object

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

        ' Get current temperature
        Dim temperature As Integer = t.GetTemperature()
        Console.WriteLine("Temperature: " + (temperature/100.0).ToString() + " °C")

        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 Thermocouple Bricklet

    ' Callback subroutine for temperature callback
    Sub TemperatureCB(ByVal sender As BrickletThermocouple, _
                      ByVal temperature As Integer)
        Console.WriteLine("Temperature: " + (temperature/100.0).ToString() + " °C")
    End Sub

    Sub Main()
        Dim ipcon As New IPConnection() ' Create IP connection
        Dim t As New BrickletThermocouple(UID, ipcon) ' Create device object

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

        ' Register temperature callback to subroutine TemperatureCB
        AddHandler t.TemperatureCallback, AddressOf TemperatureCB

        ' Set period for temperature callback to 1s (1000ms)
        ' Note: The temperature callback is only called every second
        '       if the temperature has changed since the last call!
        t.SetTemperatureCallbackPeriod(1000)

        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 Thermocouple Bricklet

    ' Callback subroutine for temperature reached callback
    Sub TemperatureReachedCB(ByVal sender As BrickletThermocouple, _
                             ByVal temperature As Integer)
        Console.WriteLine("Temperature: " + (temperature/100.0).ToString() + " °C")
    End Sub

    Sub Main()
        Dim ipcon As New IPConnection() ' Create IP connection
        Dim t As New BrickletThermocouple(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)
        t.SetDebouncePeriod(10000)

        ' Register temperature reached callback to subroutine TemperatureReachedCB
        AddHandler t.TemperatureReachedCallback, AddressOf TemperatureReachedCB

        ' Configure threshold for temperature "greater than 30 °C"
        t.SetTemperatureCallbackThreshold(">"C, 30*100, 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 BrickletThermocouple(ByVal uid As String, ByVal ipcon As IPConnection)

Creates an object with the unique device ID uid:

Dim thermocouple As New BrickletThermocouple("YOUR_DEVICE_UID", ipcon)

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

Function BrickletThermocouple.GetTemperature() As Integer

Returns the temperature of the thermocouple. The value is given in °C/100, e.g. a value of 4223 means that a temperature of 42.23 °C is measured.

If you want to get the temperature periodically, it is recommended to use the TemperatureCallback callback and set the period with SetTemperatureCallbackPeriod().

Advanced Functions

Sub BrickletThermocouple.SetConfiguration(ByVal averaging As Byte, ByVal thermocoupleType As Byte, ByVal filter As Byte)

You can configure averaging size, thermocouple type and frequency filtering.

Available averaging sizes are 1, 2, 4, 8 and 16 samples.

As thermocouple type you can use B, E, J, K, N, R, S and T. If you have a different thermocouple or a custom thermocouple you can also use G8 and G32. With these types the returned value will not be in °C/100, it will be calculated by the following formulas:

  • G8: value = 8 * 1.6 * 2^17 * Vin
  • G32: value = 32 * 1.6 * 2^17 * Vin

where Vin is the thermocouple input voltage.

The frequency filter can be either configured to 50Hz or to 60Hz. You should configure it according to your utility frequency.

The conversion time depends on the averaging and filter configuration, it can be calculated as follows:

  • 60Hz: time = 82 + (samples - 1) * 16.67
  • 50Hz: time = 98 + (samples - 1) * 20

The default configuration is 16 samples, K type and 50Hz.

The following constants are available for this function:

  • BrickletThermocouple.AVERAGING_1 = 1
  • BrickletThermocouple.AVERAGING_2 = 2
  • BrickletThermocouple.AVERAGING_4 = 4
  • BrickletThermocouple.AVERAGING_8 = 8
  • BrickletThermocouple.AVERAGING_16 = 16
  • BrickletThermocouple.TYPE_B = 0
  • BrickletThermocouple.TYPE_E = 1
  • BrickletThermocouple.TYPE_J = 2
  • BrickletThermocouple.TYPE_K = 3
  • BrickletThermocouple.TYPE_N = 4
  • BrickletThermocouple.TYPE_R = 5
  • BrickletThermocouple.TYPE_S = 6
  • BrickletThermocouple.TYPE_T = 7
  • BrickletThermocouple.TYPE_G8 = 8
  • BrickletThermocouple.TYPE_G32 = 9
  • BrickletThermocouple.FILTER_OPTION_50HZ = 0
  • BrickletThermocouple.FILTER_OPTION_60HZ = 1
Sub BrickletThermocouple.GetConfiguration(ByRef averaging As Byte, ByRef thermocoupleType As Byte, ByRef filter As Byte)

Returns the configuration as set by SetConfiguration().

The following constants are available for this function:

  • BrickletThermocouple.AVERAGING_1 = 1
  • BrickletThermocouple.AVERAGING_2 = 2
  • BrickletThermocouple.AVERAGING_4 = 4
  • BrickletThermocouple.AVERAGING_8 = 8
  • BrickletThermocouple.AVERAGING_16 = 16
  • BrickletThermocouple.TYPE_B = 0
  • BrickletThermocouple.TYPE_E = 1
  • BrickletThermocouple.TYPE_J = 2
  • BrickletThermocouple.TYPE_K = 3
  • BrickletThermocouple.TYPE_N = 4
  • BrickletThermocouple.TYPE_R = 5
  • BrickletThermocouple.TYPE_S = 6
  • BrickletThermocouple.TYPE_T = 7
  • BrickletThermocouple.TYPE_G8 = 8
  • BrickletThermocouple.TYPE_G32 = 9
  • BrickletThermocouple.FILTER_OPTION_50HZ = 0
  • BrickletThermocouple.FILTER_OPTION_60HZ = 1
Sub BrickletThermocouple.GetErrorState(ByRef overUnder As Boolean, ByRef openCircuit As Boolean)

Returns the current error state. There are two possible errors:

  • Over/Under Voltage and
  • Open Circuit.

Over/Under Voltage happens for voltages below 0V or above 3.3V. In this case it is very likely that your thermocouple is defective. An Open Circuit error indicates that there is no thermocouple connected.

You can use the ErrorStateCallback callback to automatically get triggered when the error state changes.

Function BrickletThermocouple.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 BrickletThermocouple.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 BrickletThermocouple.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:

  • BrickletThermocouple.FUNCTION_SET_TEMPERATURE_CALLBACK_PERIOD = 2
  • BrickletThermocouple.FUNCTION_SET_TEMPERATURE_CALLBACK_THRESHOLD = 4
  • BrickletThermocouple.FUNCTION_SET_DEBOUNCE_PERIOD = 6
  • BrickletThermocouple.FUNCTION_SET_CONFIGURATION = 10
Sub BrickletThermocouple.SetResponseExpectedAll(ByVal responseExpected As Boolean)

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

Sub BrickletThermocouple.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 BrickletThermocouple.SetTemperatureCallbackPeriod(ByVal period As Long)

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

The TemperatureCallback callback is only triggered if the temperature has changed since the last triggering.

The default value is 0.

Function BrickletThermocouple.GetTemperatureCallbackPeriod() As Long

Returns the period as set by SetTemperatureCallbackPeriod().

Sub BrickletThermocouple.SetTemperatureCallbackThreshold(ByVal option As Char, ByVal min As Integer, ByVal max As Integer)

Sets the thresholds for the TemperatureReachedCallback callback.

The following options are possible:

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

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

The following constants are available for this function:

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

Returns the threshold as set by SetTemperatureCallbackThreshold().

The following constants are available for this function:

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

Sets the period in ms with which the threshold callback

is triggered, if the threshold

keeps being reached.

The default value is 100.

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

AddHandler thermocouple.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 BrickletThermocouple.TemperatureCallback(ByVal sender As BrickletThermocouple, ByVal temperature As Integer)

This callback is triggered periodically with the period that is set by SetTemperatureCallbackPeriod(). The parameter is the temperature of the thermocouple.

The TemperatureCallback callback is only triggered if the temperature has changed since the last triggering.

Event BrickletThermocouple.TemperatureReachedCallback(ByVal sender As BrickletThermocouple, ByVal temperature As Integer)

This callback is triggered when the threshold as set by SetTemperatureCallbackThreshold() is reached. The parameter is the temperature of the thermocouple.

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

Event BrickletThermocouple.ErrorStateCallback(ByVal sender As BrickletThermocouple, ByVal overUnder As Boolean, ByVal openCircuit As Boolean)

This Callback is triggered every time the error state changes (see GetErrorState()).

Constants

Const BrickletThermocouple.DEVICE_IDENTIFIER

This constant is used to identify a Thermocouple 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 BrickletThermocouple.DEVICE_DISPLAY_NAME

This constant represents the human readable name of a Thermocouple Bricklet.