Visual Basic example

The Visual Basic example is slightly more complex because Visual Basic has no direct equivalent of OUT in QBasic or _outp() in Visual C++ . This means you have to write a DLL or use someone else's . We will choose the latter .

Download inpout32.zip

Unzip the file and follow the instructions in the file called inpout32.txt
Put the inpout32.dll in c:\windows, c:\windows\system and
your program's default directory to insure your program can find it.

Now lets create a simple program to test the simple circuit . First create a new project and place 2 command buttons on this form , call one of the buttons LED on and the other LED off.

figure 1 : Visual Basic layout

Now enter this in the general declarations section

Private Declare Function Inp Lib "inpout32.dll" _
Alias "Inp32" (ByVal PortAddress As Integer) As Integer
Private Declare Sub Out Lib "inpout32.dll" _
Alias "Out32" (ByVal PortAddress As Integer, ByVal Value As Integer)

Dim Port1 As Integer

Now enter the following in the LEDS ON command button's click procedure

Private Sub Command1_Click()
Port1 = 888
Out Port1, 1
End Sub

Now enter the following in the LEDS OFF command button's click procedure

Private Sub Command2_Click()
Port1 = 888
Out Port1, 0
End Sub

Now run your program and test out the buttons , viola the led switches on and off .

Download

ledflash.frm
ledflash.vbp
ledflash.exe