USB to VB.NET

[Andre_Pretorius]

Can someone please assist me, i am trying to get a PIC18F4550 to talk to a VB application.
If i connect the pic the software detects the pic but no data comes through.
I have hard coded the data witch should be sended.
any advice on how to send data back to the PIC would also be appreciated

PIC Code

DEFINE OSC 48          
DEFINE LOADER_USED 1

USBBufferSizeTX    con 8  ' input 
USBBufferSizeRX    con 8  ' output

' the USB buffer...
USBBufferTX       Var Byte[USBBufferSizeTX]
USBBufferRX       Var Byte[USBBufferSizeRX] 
USBBufferCount   Var Byte 

' ************************************************************
' * main program loop - remember, you must keep the USB      *
' * connection alive with a call to USBService every couple  *
' * of milliseconds or so...                                 *
' ************************************************************
usbinit ' initialise USB...
ProgramStart: 
	USBBufferTX[0] = "1"
	USBBufferTX[1] = "2"
	USBBufferTX[2] = "3"
	USBBufferTX[3] = "4"
	USBBufferTX[4] = "5"
	USBBufferTX[5] = "6"
	USBBufferTX[6] = "7"
	USBBufferTX[7] = "8"
   gosub DoUSBIn
   gosub DoUSBOut
   goto ProgramStart   

' ************************************************************
' * receive data from the USB bus                            *
' ************************************************************
DoUSBIn:
   USBBufferCount = USBBufferSizeRX              ' RX buffer size
   USBService                                    ' keep connection alive
   USBIn 1, USBBufferRX, USBBufferCount, DoUSBIn   ' read data, if available
   return
    
' ************************************************************
' * wait for USB interface to attach                         *
' ************************************************************
DoUSBOut:
   USBBufferCount = USBBufferSizeTX              ' TX buffer size
   USBService                                    ' keep connection alive
   USBOut 1, USBBufferTX, USBBufferCount, DoUSBOut ' if bus available, transmit data
   return

VB.NET code the form only contains textboxes and i use VB.NET2008

Option Strict Off
Option Explicit On

Friend Class MainForm
    Inherits System.Windows.Forms.Form

    ' vendor and product IDs
    Private Const VendorID As Short = 6017
    Private Const ProductID As Short = 2000

    ' read and write buffers
    Private Const BufferInSize As Short = 8
    Private Const BufferOutSize As Short = 8
    Dim BufferIn(BufferInSize) As Byte
    Dim BufferOut(BufferOutSize) As Byte

    ' ****************************************************************
    ' when the form loads, connect to the HID controller - pass
    ' the form window handle so that you can receive notification
    ' events...
    '*****************************************************************
    Private Sub MainForm_Load(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles MyBase.Load
        ' do not remove!
        ConnectToHID(Me.Handle.ToInt32)
    End Sub

    '*****************************************************************
    ' disconnect from the HID controller...
    '*****************************************************************
    Private Sub MainForm_FormClosed(ByVal eventSender As System.Object, ByVal eventArgs As System.Windows.Forms.FormClosedEventArgs) Handles Me.FormClosed
        DisconnectFromHID()
    End Sub

    '*****************************************************************
    ' a HID device has been plugged in...
    '*****************************************************************
    Public Sub OnPlugged(ByVal pHandle As Integer)
        If hidGetVendorID(pHandle) = VendorID And hidGetProductID(pHandle) = ProductID Then
            ' ** YOUR CODE HERE **
            TextBox1.Text = "plugged"
        End If
    End Sub

    '*****************************************************************
    ' a HID device has been unplugged...
    '*****************************************************************
    Public Sub OnUnplugged(ByVal pHandle As Integer)
        If hidGetVendorID(pHandle) = VendorID And hidGetProductID(pHandle) = ProductID Then
            hidSetReadNotify(hidGetHandle(VendorID, ProductID), False)
            TextBox1.Text = "unplugged"
        End If
    End Sub

    '*****************************************************************
    ' controller changed notification - called
    ' after ALL HID devices are plugged or unplugged
    '*****************************************************************
    Public Sub OnChanged()
        ' get the handle of the device we are interested in, then set
        ' its read notify flag to true - this ensures you get a read
        ' notification message when there is some data to read...
        Dim pHandle As Integer
        pHandle = hidGetHandle(VendorID, ProductID)
        hidSetReadNotify(hidGetHandle(VendorID, ProductID), True)
    End Sub

    '*****************************************************************
    ' on read event...
    '*****************************************************************
    Public Sub OnRead(ByVal pHandle As Integer)
        ' read the data (don't forget, pass the whole array)...
        If hidRead(pHandle, BufferIn(0)) Then
            ' ** YOUR CODE HERE **
            ' first byte is the report ID, e.g. BufferIn(0)
            ' the other bytes are the data from the microcontroller...
            TextBox2.Text = BufferIn(0)
            TextBox3.Text = BufferIn(1)
            TextBox4.Text = BufferIn(2)
            TextBox5.Text = BufferIn(3)
            TextBox6.Text = BufferIn(4)
            TextBox7.Text = BufferIn(5)
            TextBox8.Text = BufferIn(6)
            TextBox9.Text = BufferIn(7)
        End If
    End Sub
End Class

[Darrel Taylor]

After setting the data in the TX buffer, the first thing you do is ...
gosub DoUSBIn

It will sit there until it receives something from the PC, and nothing will be sent.
The VB program doesn't send anything, so it's stuck in the DoUSBIn subroutine.

The subroutine can be changed to continue if nothing is received.

[ardhuru]

It will sit there until it receives something from the PC, and nothing will be sent.
The VB program doesn't send anything, so it's stuck in the DoUSBIn subroutine.

Precisely where I am stuck in my misadventures with USB.

I dont think I have fully understood the syntax and the arguments for USBIN;

How exactly do you timeout and get out of the subroutine, Darrel?

"USBIn 1, USBBuffer, USBBufferCount, DoUSBIn"

Is it by changing the last argument, or is there any other way?

Anand

[Andre_Pretorius]

After looking at some other code this is what i did and it works, now for the next one sending data from the VB application

' ************************************************************
' * receive data from the USB bus                            *
' ************************************************************
DoUSBIn:
   USBBufferCount = USBBufferSizeRX              ' RX buffer size
   USBService                                    ' keep connection alive
   USBIn 1, USBBufferRX, USBBufferCount, Timeout   ' read data, if available
Timeout:                                            '
   return
    
' ************************************************************
' * wait for USB interface to attach                         *
' ************************************************************
DoUSBOut:
 WaitPC:
   USBBufferCount = USBBufferSizeTX              ' TX buffer size
   USBService                                    ' keep connection alive
   USBOut 1, USBBufferTX, USBBufferCount, Waitpc ' if bus available, transmit data
   return

[rsocor01]

After looking at some other code this is what i did and it works, now for the next one sending data from the VB application

' ************************************************************
' * receive data from the USB bus                            *
' ************************************************************
DoUSBIn:
   USBBufferCount = USBBufferSizeRX              ' RX buffer size
   USBService                                    ' keep connection alive
   USBIn 1, USBBufferRX, USBBufferCount, Timeout   ' read data, if available
Timeout:                                            '
   return
    
' ************************************************************
' * wait for USB interface to attach                         *
' ************************************************************
DoUSBOut:
 WaitPC:
   USBBufferCount = USBBufferSizeTX              ' TX buffer size
   USBService                                    ' keep connection alive
   USBOut 1, USBBufferTX, USBBufferCount, Waitpc ' if bus available, transmit data
   return

For DoUSBin that is also what I did to get out of the loop. However, I don't know if that is the best solution. The problem that I found with this approach is that I lost some of the incoming USB data. Somehow, some of the USB data going to the PIC got lost while the PIC was doing something else. I don't know if the incomming data sits in the PIC buffers waiting to be read or not.

I got the best results by combinning the original DoUSBin routine with the modified one.

Robert

[Darrel Taylor]

Another easy way is to use USB_ASM_Service.pbp ...
http://www.picbasic.co.uk/forum/show...8306#post78306

Then you don't have to worry about adding USBSERVICE or USBINIT, it's handled by the USB interrupts.

It also tells you when something has been received, so you can gosub to DoUSBin only when needed.

Main:
    IF RX_READY THEN GOSUB DoUSBin
; ...
GOTO Main

Has a TX_READY too, which tells you when it's ok to send, instead of getting locked up in the DoUSBout routine.

hth,