Windows with Mono
Welcome to using Phidgets with Visual Basic! By using Visual Basic, 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
● 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. 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 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 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 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 code will be:
● The Phidget22 API documentation
● The VB 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 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.
