USB to VB.NET [Archive] - MEL PICBASIC Forum

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Andre_Pretorius

- 24th June 2010, 18:44

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

- 24th June 2010, 19:26

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

- 25th June 2010, 13:27

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

- 25th June 2010, 14:58

rsocor01

- 25th June 2010, 19:14

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

- 25th June 2010, 20:43

Another easy way is to use USB_ASM_Service.pbp ...
http://www.picbasic.co.uk/forum/showthread.php?t=11728&p=78306#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,

Andre_Pretorius

- 26th June 2010, 14:17

Thanks Darrel after looking at your code i changed the code to look like the this, it works fine, i will again post some code if i get the VB code to send some data.

include "USB_ASM_Service.pbp"
DEFINE LOADER_USED 1
Define OSC 48

' ************************************************** ***
bufferRX Var Byte[8]
bufferTX Var Byte[8]
cntRX Var Byte
cntRX = 8 ' Specify input buffer size
cntTX Var Byte
cntTX = 8 ' Specify output buffer size
LED Var PORTD.7
' ************************************************** **

Main:
IF Plugged THEN 'indicate conection to PC
LED = 1
ELSE
LED = 0
ENDIF

IF RX_READY THEN ; USB data has been rcvd
RX_READY = 0 ; clear the Ready flag
USBIN 1, BufferRX, CntRX, Main
ENDIF

IF TX_READY THEN ; USB is Ready to transmit
TX_READY = 0 ; clear the Ready flag
USBOUT 1, BufferTX, CntTX, TXfail
TXfail:
ENDIF

bufferTX[0] = 1
bufferTX[1] = 2
bufferTX[2] = 3
bufferTX[3] = 4
bufferTX[4] = 5
bufferTX[5] = 6
bufferTX[6] = 7
bufferTX[7] = 8

Goto Main

Andre_Pretorius

- 14th July 2010, 19:30

Hi there, i am back still batteling with the VB.net part of my project, i have tried this code to send data to my pic when i press a button, it does not work, i know this is not a vb forum but mabe someone can give me some advice
thank you

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim pHandle As Integer
pHandle = hidGetHandle(VendorID, ProductID)
BufferOut(0) = 1
BufferOut(1) = 2
BufferOut(2) = 3
BufferOut(3) = 4
BufferOut(4) = 5
BufferOut(5) = 6
BufferOut(6) = 7
BufferOut(7) = 8
hidWrite(pHandle, BufferOut(0))
End Sub

rsocor01

- 14th July 2010, 22:55

Andre,

I created my application using EasyHID. The code is in VB6 and it works fine. If you think that it might help you, I will post the VB6 code here.

The VB code in your first post has the "plugged", "unplugged", and "OnRead" subroutines, but I don't see the "WriteSomeData" routine that exists in the VB6 version. What program did you use to get this code? Was it HIDMaker?

Robert

ardhuru

- 15th July 2010, 17:52

Robert, I would love to see your VB code; like I said earlier, I too managed to send data from the pic to the PC, but the reverse is just not happening.

Regards,

Anand

rsocor01

- 16th July 2010, 04:53

The following VB6 code is created by EasyHID. It is a subroutine to send bytes from the computer to the MCU. You need to comment out the BufferOut(0) and BufferOut(1) lines like I did below.

'************************************************* ****************
' this is how you write some data...
'************************************************* ****************
Public Sub WriteSomeData()
' BufferOut(0) = 0 ' first by is always the report ID
' BufferOut(1) = 10 ' first data item, etc etc

' write the data (don't forget, pass the whole array)...
hidWriteEx VendorID, ProductID, BufferOut(0)
End Sub

All you need to do is give a value to variables BufferOut(1) to BufferOut(8) and call the WriteSomeData routine when the command button is pressed. Then, on the PIC side try to read bytes USBBuffer_IN[0] to USBBuffer_IN[7] by using the DoUSBIn routine.

Private Sub Command1_btn_Click()

BufferOut(1) = 1
BufferOut(2) = 2
BufferOut(3) = 3
BufferOut(4) = 4
BufferOut(5) = 5
BufferOut(6) = 6
BufferOut(7) = 7
BufferOut(8) = 8

WriteSomeData 'Calls routine WriteSomeData

End Sub

Robert

ardhuru

- 16th July 2010, 18:14

Robert, thanks a lot. I'll try this out soon and be back with a feedback.

Regards,

Anand

Andre_Pretorius

- 18th July 2010, 19:02

Thank you it works like a charm, now i can continue with the rest of my program, thank you once again:)