Open port USB with vb.net in PDA | Abrir el puerto USB con vb.net en PDA

[Chris Tacke, eMVP]

USB ports are *not* RS232 ports and they don't work the same. You cannot
simply "open" a USB port and send and receive data.

There are some instances where there is a serial converter driver or serial
converter device that then exposes such an interface, but they work only
with USB Host devices. USB hosting requires specific hardware which I don't
think is available in any PPCs.

 

[Edgar Hdz]

Hi everybody |<es>| Hola a todos

I have a problem with a USB; I can´t open USB port with VB.net for PDA
|<es>| Tengo un problema con el USB; no he logrado abrir el puerto USB con
VB.net

I need send text to a printer RS232 but i can´t;
|<es>| Necesito enviar texto a una impresora RS232 pero no puedo
I have USB to RS232 (Chip PL2303)
|<es>| Tengo un cable USB a RS232 (Chip PL2303)

can you help me? can you tell me how open the port?
|<es>| Prodrian ayudarme? podrian decirme como abrir el puerto?

I use CreateFile() and WriteFile() but it dosen't works
|<es>| He usado CreateFile() y WriteFile() pero no funcina

I also use CreateFile() and DeviceIOcontrol() but it dosen't works
|<es>| Tambien he usado CreateFile() y DeviceIOcontrol() y no funciona


Example Code

<DllImport("coredll.dll")> _
Private Shared Function CreateFile(ByVal lpFileName As String, _
ByVal dwDesiredAccess As Integer, ByVal dwShareMode As Integer, _
ByVal lpSecurityAttributes As Integer, ByVal dwCreationDisposition
As Integer, _
ByVal dwFlagsAndAttributes As Integer, ByVal hTemplateFile As
Integer) As Integer
End Function
<DllImport("coredll.dll")> _
Private Shared Function DeviceIoControl( _
ByVal hDevice As Int32, ByVal dwIoControlCode As Int32, _
ByRef lpInBuffer As Int32, ByVal nInBufferSize As Int32, _
ByRef lpOutBuffer As String, ByVal nOutBufferSize As Int32, _
ByRef lpBytesReturned As Int32, ByRef lpOverlapped As Int32) As
Int32
End Function
<DllImport("coredll.dll")> _
Private Shared Function WriteFile( _
ByVal hFile As Int32, ByVal Buffer As Byte(), ByVal
nNumberOfBytesToWrite As Int32, _
ByVal lpNumberOfBytesWritten As Int32, ByVal overlapped As Int32)
As Int32
End Function

Function PrinterDeviceIO()
idPort = CreateFile("COM9:", GENERIC_READ Or GENERIC_WRITE, 0, 0,
OPEN_EXISTING, 0, 0)

intBF = DeviceIoControl(idPort, FILE_GENERIC_WRITE, 2048, 1,
strValue, strValue.Length, intReturn, intOver)
End Function

Function PrinterWriter()
idPort = CreateFile("COM9:", GENERIC_READ Or GENERIC_WRITE, 0, 0,
OPEN_EXISTING, 0, 0)

intBF = WriteFile(idPort, bytBuffer, bytBuffer.Length, 1024, 0)
End Function