Language - Visual Basic .NET: Difference between revisions

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Preamble about the language and its general strengths and weaknesses.
<metadesc>Communicate over USB with sensors, controllers and relays with Phidgets! Our Visual Basic .NET library supports Windows using Visual Studio or Mono.</metadesc>
[[Category:Language]]
__NOTOC__
We provide support for the Visual Basic .NET language on the '''Windows''' operating system. We also provide instructions on how to get your project started in a number of common development environments. Select your operating system and preferred development environment below, and follow the instructions to get your project running with Phidgets.


==Assessment for use with Phidgets==
If you do not know which development environment you want to use, or your development environment of choice is not listed, we recommend starting with Mono as the simplest path to getting your code running. Visual Studio is the most popular way to build Visual Basic .NET projects, but it also has a steep learning curve.
Our honest opinion on how well this language is suited to controlling Phidgets. If it is a poor choice, suggest and link similar (better) languages.


==Support==
Once you have set up your development environment to run with Phidgets, we recommend you follow our guide on [[Phidget Programming Basics]]. The guide will showcase the fundamentals of programming with Phidgets.
Visual Basic .NET has a complete API and sample code for all Phidgets devices.


For a complete list of our supported languages and their support status, [[Levels of Support|click here]].
== Setup Guide ==


==Restrictions==
<div class="phd-deck-sequence">
In this section, list any restrictions or limitations that this particular language may impose. For example, incompatibility with certain operating systems.
{{PT3_VBNET_CHOOSE}}{{PT3_VBNET_WIN_VS}}{{PT3_VBNET_WIN_MONO}}
 
==Development Environments and Compilers==
 
Describe each major compiler and notable differences or important information. (eg. framework versions) If there are known issues/workarounds mention them and link to the corresponding issue at the bottom of the page.
 
==Drivers, Libraries and Resources==
Before you can run your program, you need to set up the proper environment and get the necessary files off the Phidgets website.
Visit the drivers section at www.phidgets.com and get the latest:
* [http://www.phidgets.com/drivers.php Phidget Framework]
You will need the Phidget Framework to use and to program with Phidgets. We also recommend that you download the following reference materials:
* [http://www.phidgets.com/documentation/Phidget21.NET.zip API Manual]
* [http://www.phidgets.com/documentation/web/NETDoc/Index.html API Reference]
* [http://www.phidgets.com/downloads/examples/VBNET_2.1.8.20110616.zip VB.NET Sample Code]
* You can find a high level discussion about programming with Phidgets in general on the [[General API]] page.
* The [[Device Functionality]] page explains the general operational information for your device.
 
You may want to have these pages open while working through these instructions.
 
==Getting Started==
 
The Phidget examples were written using Visual Basic .NET 2005 and this tutorial assumes its use.
Newer versions of Visual Studio Express are freely available for download from Microsoft.
Older versions of Visual Studio work as well and would be set up in a similar manner (Note: you would have to recreate the user interface in the examples for Visual Studio versions earlier than 2005).
 
In Visual Studio:
 
* Generate a new VB.NET Windows Application with a descriptive name such as PhidgetTest.
* Launch the Add Reference window (Project | Add Reference).
* Under the .NET tab, select the most recent Phidget21.NET library. If it does not appear in this list, then you can Browse to the Phidget Framework installation directory and add the Phidget21.NET.dll. For earlier versions of Visual Studio, you will want to use the Phidget21.NET1.1.dll instead.
* Place a TextBox on your main form for the purpose of capturing output.
* Hook the form's Load and FormClosing events. Phidget initialization and shutdown will take place there.
 
The project now has access to Phidgets and we are ready to begin coding.
 
===Coding For Your Phidget===
 
A Phidget object will fist need to be declared and then initialized. For example, we can declare a PhidgetInterfaceKit inside our form with:
 
<div style="background-color: #f3f3f3; border-color: #1c9edb; border-width:1px; border-style: dashed;">
<font size="3">
<source lang=vbnet>
 
  Public Class Form1
      'The Phidget object declaration
  Dim WithEvents ifKit As Phidgets.InterfaceKit
      '... Form1_Load and Form1_OnClosing here
  End Class
 
</source>
</font>
</div>
 
The object name for any type of Phidget is listed in the API manual.
Every type of Phidget also inherits functionality from the Phidget base class.
 
===Connecting to the Phidget===
 
Next, the program needs to try and connect to the Phidget through a call to open().
Open will tell the program to continuously try to connect to a Phidget, based on the parameters given, even trying to reconnect if it gets disconnected.
This means that simply calling open does not guarantee you can immediately use the Phidget.
We can handle this by using event driven programming and tracking the AttachEvents and DetachEvents, or by calling waitForAttachment.
WaitForAttachment will block indefinitely until a connection is made to the Phidget, or an optional timeout is exceeded.
<div style="background-color: #f3f3f3; border-color: #1c9edb; border-width:1px; border-style: dashed;">
<font size="3">
<source lang=vbnet>
     
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        ifKit = New Phidgets.InterfaceKit
        ifKit.open()
        ifKit.waitForAttachment(3000)
    End Sub
 
</source>
</font>
</div>
</div>


The different types of open can be used with parameters to try and get the first device it can find, open based on its serial number, or even open across the network.
The API manual lists all of the available modes that open provides.
One important thing to remember is that when working with Phidgets, a local connection will reserve the device until closed.
This prevents any other instances from retrieving data from the Phidget, including other programs.
The one connection per device limit does not apply when exclusively using the Phidget Webservice.


===Event Driven Programming===
== Quick Downloads ==
 
If you already know what you're doing and just need the files, you can find them all below.
We recommend the use of event driven programming when working with Phidgets.
In VB.NET we can hook an event handler with the following code:
<div style="background-color: #f3f3f3; border-color: #1c9edb; border-width:1px; border-style: dashed;">
<font size="3">
<source lang=vbnet>
 
    Private Sub ifKit_SensorChange(ByVal sender As Object, ByVal e As Phidgets.Events.SensorChangeEventArgs) Handles ifKit.SensorChange
        TextBox1.Text = "Index " + e.Index.ToString() + " Value: " + e.Value.ToString()
    End Sub
 
</source>
</font>
</div>
 
With this function, the code inside ifKit_SensorChange will get executed every time the PhidgetInterfaceKit reports a change on one of its analog inputs.
Some events such as Attach and Detach belong to the base Phidget object and thus are common to all types of Phidgets.
Please refer to the API manual for a full list of events and their usage.
At the end of your program, unhook any events and call Application.DoEvents().
This will make sure there are no outstanding events being processed before calling close.
 
<div style="background-color: #f3f3f3; border-color: #1c9edb; border-width:1px; border-style: dashed;">
<font size="3">
<source lang=vbnet>
 
    Private Sub Form1_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing
        RemoveHandler ifKit.SensorChange, AddressOf ifKit_SensorChange
        Application.DoEvents()
        ifKit.close()
    End Sub
 
</source>
</font>
</div>
 
===Working directly with the Phidget===
 
Some values can be read and sent directly to the Phidget, simply use the instance members and properties.
This is also how you would set properties on the Phidget such as the output state or sensor sensitivity.
These functions can be used inside a polling loop as an alternative to event driven programming.
 
<div style="background-color: #f3f3f3; border-color: #1c9edb; border-width:1px; border-style: dashed;">
<font size="3">
<source lang=vbnet>
 
  Dim val As Integer = ifKit.sensors(0).Value
 
</source>
</font>
</div>


===Working with multiple Phidgets===
=== Documentation ===


Multiple Phidgets of the same type can easily be run inside the same program.
*{{Phidget22API}} (Select Visual Basic .NET from drop-down menu)
In our case, it requires another PhidgetInterfaceKit instance to be defined and initialized.
The new instance can then be set up, opened and used in the same process as the previous one.
If the application needs to distinguish between the devices, open can be called with the serial number of a specific Phidget.


===Other Phidgets===
=== Example Code ===


The design given in this document can also be followed for almost all Phidgets.
*{{SampleCode|VBNET|Visual Basic .NET Examples}}
For example, if you were using a PhidgetRFID instead of an PhidgetInterfacekit, you would declare an RFID object instead of an InterfaceKit.
The methods and events available would change but they can be accessed in a similar manner.


==Building your Project==
===Libraries===
Describe the different ways a project could be built using this language.


==Common Problems and Solutions/Workarounds==
{{AllQuickDownloads}}
Here you can put various frequent problems and our recommended solutions.

Latest revision as of 21:39, 10 August 2023


We provide support for the Visual Basic .NET language on the Windows operating system. We also provide instructions on how to get your project started in a number of common development environments. Select your operating system and preferred development environment below, and follow the instructions to get your project running with Phidgets.

If you do not know which development environment you want to use, or your development environment of choice is not listed, we recommend starting with Mono as the simplest path to getting your code running. Visual Studio is the most popular way to build Visual Basic .NET projects, but it also has a steep learning curve.

Once you have set up your development environment to run with Phidgets, we recommend you follow our guide on Phidget Programming Basics. The guide will showcase the fundamentals of programming with Phidgets.

Setup Guide

VB.NET - Select Development Environment

Select your Development Environment:

Windows

Language - VB.Net

Windows with Visual Studio

Welcome to using Phidgets with Visual Basic .NET! By using Visual Basic .NET, you will have access to the complete Phidget22 API, including events.

Visual Studio is an IDE provided by Microsoft that can be used to develop code in a wide variety of programming languages, including Visual Basic .NET.

Requirements

First, make sure you have the following installed:

● Phidgets Drivers for Windows (see Part 1 of this user guide)

● Microsoft Visual Studio


Nuget

The Phidget22.NET library is now available on nuget.org here. Nuget is the recommended way to install and use the .NET library in Visual Studio. The nuget package bundles the C library on Windows, so there are no other prerequisites that need to be installed. The nuget package adds targets for .NET Core and .NET Standard, so it should be usable from almost any .NET environment which also supports the C library.

Use Our Examples

One of the best ways to start programming with Phidgets is to use our example code as a guide.

VB.Net Code Samples

Download the example(s) that correspond to your Phidget's channel classes. You can find them listed on the enclosure in most cases, or on the API tab of the product page.

Use Our Examples

Unpack and open the example project and click the Start button:

The application will open the Phidget, list basic information about the Phidget, and demonstrate the Phidget's functionality. Here is an example of a Digital Output channel on a RFID Phidget:

You should now have the example up and running for your device. This would be a good time to play around with the device and experiment with some of its functionality.

Editing the Examples

The Visual Basic .Net examples are derived from the Windows Phidget Control Panel, so you'll need to modify a few things to adapt them for your own purposes. To begin with, you can remove the following line:

commandLineData phidgetParameters = open.parseCmdLine(); //get command line parameters

Then, you can modify any line that mentions phidgetParameters by setting it to the desired value instead of using PhidgetParameters object...

Editing the Examples

For instance:

Try 'set all the values grabbed from command line.  these values have defaults that are set in ExampleUtils.vb, you can check there to see them
    device.Channel = phidgetParameters.Channel 'selects the channel on the device to open
    device.DeviceSerialNumber = phidgetParameters.SerialNumber 'selects the device or hub to open
    device.HubPort = phidgetParameters.HubPort 'selects th eport on the hub to open
    device.IsHubPortDevice = phidgetParameters.isHubPortDevice 'is the device a port on a vint hub?

    If phidgetParameters.isRemote Then 'are we trying to open a remote device?
        device.IsRemote = True
        Net.EnableServerDiscovery(ServerType.Device) 'turn on network scan
        If phidgetParameters.Password <> vbNullString And 
           phidgetParameters.ServerName <> vbNullString Then
           
            Net.SetServerPassword(phidgetParameters.ServerName, phidgetParameters.Password)
        End If
    Else
        device.IsLocal = True
    End If

    device.Open() 'open the device specified by the above parameters
Catch ex As PhidgetException
    errorBox.addMessage("Error opening the device: " + ex.Message)
End Try

Might become:

Try
    device.Channel = 0
    device.DeviceSerialNumber = 370097
    device.HubPort = 0
    device.IsHubPortDevice = True
    device.IsLocal = True

    device.Open()
Catch ex As PhidgetException
    errorBox.addMessage("Error opening the device: " + ex.Message)
End Try

You can then manipulate the rest of the code as your application requires.

Write Code

You now have working examples and a project that is configured. This teaching section will help you understand how the examples were written so you can start writing your own code.

Remember: your main reference for writing VB.NET code will be:

● The Phidget22 API documentation

● The VB.Net Example Code

Write Code

Step One: Create And Address

You will need to declare your Phidget object in your code. For example, we can declare a digital input object like this:

ch = New Phidget22.DigitalInput()

Next, we can address which Phidget we want to connect to by setting parameters such as DeviceSerialNumber.

ch.DeviceSerialNumber = 496911

You can find information about all available parameters here or in the API documentation.

Write Code

Step One: Create And Address

Although we will not discuss it in-depth on this page, you should include error handling for all Phidget functions. Here is an example of the previous code with error handling:

Try
  ch = New Phidget22.DigitalInput()
  ch.DeviceSerialNumber = 496911
Catch ex As PhidgetException
  errorBox.addMessage("Error initializing: " + ex.Message)
End Try

Write Code

Step Two: Open And Wait For Attachment

After we have specified which Phidget to connect to, we can open the Phidget object like this:

ch.Open(5000)

To use a Phidget, it must be plugged in (attached). We can handle this by calling Open(timeout), which will block indefinitely until a connection is made, or until the timeout value is exceeded. Simply calling Open does not guarantee you can use the Phidget immediately.

Write Code

Alternately, you could verify the device is attached by using event driven programming and tracking the attach events.

To use events to handle attachments, we have to modify our code slightly:

Private Sub device_Attach(ByVal sender As Object, ByVal e As Phidget22.Events.AttachEventArgs) Handles ch.Attach
  Console.WriteLine("Phidget Attached!");
End Sub

We recommend using this attach handler to set any initialization parameters for the channel such as DataInterval and ChangeTrigger from within the AttachHandler, so the parameters are set as soon as the device becomes available.

Write Code

Step Three: Do Things With The Phidget

We recommend the use of event driven programming when working with Phidgets. In a similar way to handling an attach event as described above, we can also add an event handler for a state change event:

Private Sub device_DigitalInputChange(ByVal sender As Object, ByVal e As Phidget22.Events.DigitalInputStateChangeEventArgs) Handles ch.StateChange
  stateText.Text = "State: " + e.State;
End Sub

If you are using multiple Phidgets in your program, check out our page on Using Multiple Phidgets for information on how to properly address them and use them in events.

If events do not suit your needs, you can also poll the device directly for data using code like this:

state= device.State;
stateText.Text = "State: " + e.State;

Important Note: There will be a period of time between the attachment of a Phidget sensor and the availability of the first data from the device. Any attempts to get this data before it is ready will result in an exception. See more information on this on our page for Unknown Values.

Write Code

Step Three: Do Things With The Phidget

Enumerations: Some Phidget devices have functions that deal with specific predefined values called enumerations. Enumerations commonly provide readable names to a set of numbered options.

Enumerations with Phidgets in Visual Basic .NET will take the form of Phidget22.EnumerationType.Enumeration_Name.

For example, specifying a SensorType to use the 1142 for a voltage input would look like:

Phidget22.VoltageSensorType.PN_1142

and specifying a K-Type thermocouple for a temperature sensor would be:

Phidget22.ThermocoupleType.K

The Phidget error code for timing out could be specified as:

Phidget22.ErrorCode.Timeout

Write Code

Step Four: Close And Delete

At the end of your program, be sure to close and delete your device:

device.Close();

Setting up a New Project

When you are building a project from scratch, or adding Phidget functionality to an existing project, you'll need to configure your development environment to properly link the Phidget .NET library. To begin:

Create a new Windows Forms Application project:

Setting up a New Project

Next, right-click to add a reference to the Phidget .NET library:

Setting up a New Project

On the following screen, click Browse and navigate to the location of Phidget22.NET.dll:

Setting up a New Project

Finally, to include the Phidget .NET library, add the following lines to main window class file:

Imports Phidget22
Imports Phidget22.Events

Success! The project now has access to Phidgets.

What's Next?

Now that you've set up Phidgets in your programming environment, you should read our guide on Phidget Programming Basics to learn the fundamentals of programming with Phidgets.

Continue reading below for advanced information and troubleshooting for your device.

«
»

Language - VB.Net

Windows with Mono

Welcome to using Phidgets with Visual Basic .NET! By using Visual Basic .NET, you will have access to the complete Phidget22 API, including events.

Mono is an open-source programming environment that aims to make Microsoft .NET applications available across all operating systems.

Requirements

First, make sure you have the following installed:

● Phidgets Drivers for Windows (see Part 1 of this user guide)

Mono


Nuget

The Phidget22.NET library is now available on nuget.org here. Nuget is the recommended way to install and use the .NET library in Visual Studio. The nuget package bundles the C library on Windows, so there are no other prerequisites that need to be installed. The nuget package adds targets for .NET Core and .NET Standard, so it should be usable from almost any .NET environment which also supports the C library.

Use Our Examples

First, download and unpack the HelloWorld example for VB.Net. This example uses the Phidget Manager to list all Phidget channels that can be accessed by your computer:

HelloWorld example

Note: The HelloWorld example is compatible with Mono because it does not use Windows Forms. All other VB.Net examples use Windows Forms.

Use Our Examples

Next, copy Phidget22.NET.dll from type the following location:

● C:\Program Files\Phidgets\Phidget22\Phidget22.NET.dll

Place both the HelloWorld example and the Phidget22.NET.dll file in the same location. Your folder should now look something like this:

Use Our Examples

Open the command prompt at the folder location and enter the following command:

vbnc /r:Phidget22.NET.dll Module1.vb

This will create an executable file called Module1.exe. Type in the following command to run the example:

mono Module1.exe

Use Our Examples

You should be able to see the channels of your Phidget listed when the program starts or whenever the Phidget is plugged in while the program is running.

Now that you've confirmed that your devices are properly connected, the next step is to download and edit sample code for your specific device.

Use Our Examples

To download the code samples, visit this page:

VB.Net Code Samples

Download the example(s) that correspond to your Phidget's channel classes. You can find them listed on the enclosure in most cases, or on the API tab of the product page.

Editing the Examples

The Visual Basic .Net examples are derived from the Windows Phidget Control Panel, so you'll need to modify a few things to adapt them for your own purposes. To begin with, you can remove the following line:

commandLineData phidgetParameters = open.parseCmdLine(); //get command line parameters

Then, you can modify any line that mentions phidgetParameters by setting it to the desired value instead of using PhidgetParameters object...

Editing the Examples

For instance:

Try 'set all the values grabbed from command line.  these values have defaults that are set in ExampleUtils.vb, you can check there to see them
    device.Channel = phidgetParameters.Channel 'selects the channel on the device to open
    device.DeviceSerialNumber = phidgetParameters.SerialNumber 'selects the device or hub to open
    device.HubPort = phidgetParameters.HubPort 'selects th eport on the hub to open
    device.IsHubPortDevice = phidgetParameters.isHubPortDevice 'is the device a port on a vint hub?

    If phidgetParameters.isRemote Then 'are we trying to open a remote device?
        device.IsRemote = True
        Net.EnableServerDiscovery(ServerType.Device) 'turn on network scan
        If phidgetParameters.Password <> vbNullString And 
           phidgetParameters.ServerName <> vbNullString Then
           
            Net.SetServerPassword(phidgetParameters.ServerName, phidgetParameters.Password)
        End If
    Else
        device.IsLocal = True
    End If

    device.Open() 'open the device specified by the above parameters
Catch ex As PhidgetException
    errorBox.addMessage("Error opening the device: " + ex.Message)
End Try

Might become:

Try
    device.Channel = 0
    device.DeviceSerialNumber = 370097
    device.HubPort = 0
    device.IsHubPortDevice = True
    device.IsLocal = True

    device.Open()
Catch ex As PhidgetException
    errorBox.addMessage("Error opening the device: " + ex.Message)
End Try

You can then manipulate the rest of the code as your application requires.

Write Code

You now have working examples and a project that is configured. This teaching section will help you understand how the examples were written so you can start writing your own code.

Remember: your main reference for writing VB.NET code will be:

● The Phidget22 API documentation

● The VB.Net Example Code

Write Code

Step One: Create And Address

You will need to declare your Phidget object in your code. For example, we can declare a digital input object like this:

ch = New Phidget22.DigitalInput()

Next, we can address which Phidget we want to connect to by setting parameters such as DeviceSerialNumber.

ch.DeviceSerialNumber = 496911

You can find information about all available parameters here or in the API documentation.

Write Code

Step One: Create And Address

Although we will not discuss it in-depth on this page, you should include error handling for all Phidget functions. Here is an example of the previous code with error handling:

Try
  ch = New Phidget22.DigitalInput()
  ch.DeviceSerialNumber = 496911
Catch ex As PhidgetException
  errorBox.addMessage("Error initializing: " + ex.Message)
End Try

Write Code

Step Two: Open And Wait For Attachment

After we have specified which Phidget to connect to, we can open the Phidget object like this:

ch.Open(5000)

To use a Phidget, it must be plugged in (attached). We can handle this by calling Open(timeout), which will block indefinitely until a connection is made, or until the timeout value is exceeded. Simply calling Open does not guarantee you can use the Phidget immediately.

Write Code

Alternately, you could verify the device is attached by using event driven programming and tracking the attach events.

To use events to handle attachments, we have to modify our code slightly:

Private Sub device_Attach(ByVal sender As Object, ByVal e As Phidget22.Events.AttachEventArgs) Handles ch.Attach
  Console.WriteLine("Phidget Attached!");
End Sub

We recommend using this attach handler to set any initialization parameters for the channel such as DataInterval and ChangeTrigger from within the AttachHandler, so the parameters are set as soon as the device becomes available.

Write Code

Step Three: Do Things With The Phidget

We recommend the use of event driven programming when working with Phidgets. In a similar way to handling an attach event as described above, we can also add an event handler for a state change event:

Private Sub device_DigitalInputChange(ByVal sender As Object, ByVal e As Phidget22.Events.DigitalInputStateChangeEventArgs) Handles ch.StateChange
  stateText.Text = "State: " + e.State;
End Sub

If you are using multiple Phidgets in your program, check out our page on Using Multiple Phidgets for information on how to properly address them and use them in events.

If events do not suit your needs, you can also poll the device directly for data using code like this:

state= device.State;
stateText.Text = "State: " + e.State;

Important Note: There will be a period of time between the attachment of a Phidget sensor and the availability of the first data from the device. Any attempts to get this data before it is ready will result in an exception. See more information on this on our page for Unknown Values.

Write Code

Step Three: Do Things With The Phidget

Enumerations: Some Phidget devices have functions that deal with specific predefined values called enumerations. Enumerations commonly provide readable names to a set of numbered options.

Enumerations with Phidgets in Visual Basic .NET will take the form of Phidget22.EnumerationType.Enumeration_Name.

For example, specifying a SensorType to use the 1142 for a voltage input would look like:

Phidget22.VoltageSensorType.PN_1142

and specifying a K-Type thermocouple for a temperature sensor would be:

Phidget22.ThermocoupleType.K

The Phidget error code for timing out could be specified as:

Phidget22.ErrorCode.Timeout

Write Code

Step Four: Close And Delete

At the end of your program, be sure to close and delete your device:

device.Close();

Setting up a New Project

When you are building a project from scratch, or adding Phidget functionality to an existing project, you'll need to configure your development environment to properly link the Phidget .NET library. To begin:

To include the Phidget .NET library, simply add the following lines to your code:

Imports Phidget22
Imports Phidget22.Events

Setting up a New Project

Next, copy Phidget22.NET.dll from the following location:

● C:\Program Files\Phidgets\Phidget22\Phidget22.NET.dll

Place your program and the Phidget22.NET.dll file in the same location. Your folder should now look something like this:

Setting up a New Project

Open the command prompt at the folder location and enter the following command:

vbnc /r:Phidget22.NET.dll Module1.vb

This will create an executable file called Module1.exe. Type in the following command to run the example:

mono Module1.exe

Success! The project now has access to Phidgets.

What's Next?

Now that you've set up Phidgets in your programming environment, you should read our guide on Phidget Programming Basics to learn the fundamentals of programming with Phidgets.

Continue reading below for advanced information and troubleshooting for your device.

«
»


Quick Downloads

If you already know what you're doing and just need the files, you can find them all below.

Documentation

Example Code

Libraries