Anyone know whats wrong with this code

[Jerson]

Bonxy

First of all, I must clarify, I haven't used VB express till now. But, on the face of it, you need to do something differently.

'--------------------------------------------------------------------------

Using comPort As SerialPort = My.Computer.Ports.OpenSerialPort("COM1", 9600)
comPort.DtrEnable = True
comPort.Write("S")

' All data transfer code goes here.

End Using

'All the above works
'------------------------------------------------------------------------
'All below does not work

Dim buffer As New StringBuilder()
Using comPort As SerialPort = My.Computer.Ports.OpenSerialPort("COM1")
Do
Dim line As String = comPort.ReadLine()
If line Is Nothing Then
Exit Do
Else
buffer.AppendLine(line)
End If
Loop
End Using
'--------------------------------------------------------------------------

The above code of yours needs to be modified so that the using block encompasses the entire code. Something like this

'--------------------------------------------------------------------------

Using comPort As SerialPort = My.Computer.Ports.OpenSerialPort("COM1", 9600)
comPort.DtrEnable = True
comPort.Write("S")

' All data transfer code goes here.

'All the above works
'------------------------------------------------------------------------
'All below does not work

Dim buffer As New StringBuilder()
Do
Dim line As String = comPort.ReadLine()
If line Is Nothing Then
Exit Do
Else
buffer.AppendLine(line)
End If
Loop
End Using
'--------------------------------------------------------------------------

I suspect that the OpenSerialPort method destroys whatever data is held in the receiver buffer uptil that time. So, you should try and see if you can open the serial port at the start of your program and close it at the end of your program. Rest of the time, just use it without the using/endusing clauses.

Hope this helps

Jerson

[Bonxy]

Hi Jerson

I tried the mod u suggest but it does not work, it locks the prog up as before.
I was looking on the MS website and i think i found a clue, I may be placing the code in the wrong place ?.
The MS example i found uses a command line interface with the code snips place in a code module.
What i am doing is simply placing a button on a form and putting the code snips in the buttonclick sub.

The worst thing is that MS doesnt provide a simple working example and i cant find anyone that KNOWS how to do this one simple thing, its driving me bloody nuts.

[Jerson]

Bonxy

try the usual way. Like I said, at application startup, do the openserialport method call(without the using keyword). Then when you are about to close the app, close serial port(dont know if theres a method for this). I wouldnt mind giving it a shot, but it will take a couple of days since I am very tied up right now with other assignments.
Perhaps you could ZIP attach the app for me to look at.

Jerson

[Bonxy]

Jerson

Thanks for your offer but i have to get this thing working today, i am going to try to find a book that explains it.

If anyone knows how to do serial comms in VB Express please help.

[mister_e]

Probably harder for sure, but the windows API call method should work.

How to in VBExpress? i wish i could help better.... i don't know.