USBDemo, something to learn USB a little bit

[Josuetas]

Other than that, since you can find the handle of each device with the same Vendor/Product ID, within your software you can create a Challenge/Response type arrangement that will let the computer assign a unique number to any new devices on the BUS.

Ok i will use Darrel´s exe program.

I know it will not be exactly the same for VB but if there is any chance that you could post the source code i would finally see how it´s done!

I am sure i can do with just the handler, i could also identify wich device was connected first and have a record of devices....

This would be a great place to begin

Thanks for your replies

DJC

[Darrel Taylor]

Ok i will use Darrel´s exe program.

Thank You!<hr>
Looking at the VB side of USBDemo

Public Sub OnPlugged(ByVal pHandle As Long)
    '
    '   A HID device has been plugged in,
    '   check if it's the right one, and enable the form LED (top left)
    '
    Dim DeviceHandle As Long
    Dim VendorName As String * 15
    Dim ProductName As String * 15
    
    If hidGetVendorID(pHandle) = VendorID And hidGetProductID(pHandle) = ProductID Then ' Good one?
        '
        '   get the device handle
        '   =====================
        DeviceHandle = hidGetHandle(VendorID, ProductID)
        '
        '   Get the vendor and product name from the handle
        '   ===============================================
        hidGetVendorName DeviceHandle, VendorName, 255
        hidGetProductName DeviceHandle, ProductName, 255
        '
        '   Enable the LED and display device information
        '   VendorName and ProductName
        '   =============================================
        imgON.Visible = True
        lVendorName.Caption = VendorName
        lProductName.Caption = ProductName
        End If
End Sub

Using the line shown in red, anytime a device is plugged in with the same Vendor/Product ID, it will forget about the last device and start using the new one.

To get around that, you need to check further to make sure it's the device you want to talk to. And, for that, you need to search through the HID Device list.

Again, I don't do VB, so the syntax is most probably wrong. But ...<hr>
The function hidGetItemCount returns the number of HID devices in the List.
Then hidGetItem(Index) returns the handle of the item in the list that's specified by Index (0 to count-1).

You can get the info about that device by requesting each field.
Vendor = hidGetVendorID(handle)
Product = hidGetProductID(handle)
Serial = hidGetSerialNumber(handle)

Now if everything matches, you know you have the right one. If not, keep searching through the list.

If you're not using the Serial Number, you'll need to send/receive something to the device to figure out if it's the correct one.

Is that any help?
I'll keep trying if not.
<br>

[atwoz]

Steve, do I need the 18f4550 or any other USB pic for your USB project? or can I do it with a standard pic, like the 18f452?

[mister_e]

Atwoz, only USB PIC will work!

[atwoz]

Ok Thanks Steve! Looks like I will have to buy some 18f4550 .

[mister_e]

Well, one in the list... 18F4550, 2550,2455, 4455 they all works.

As you'll see, it's fun to have it's first working USB project....even if you're aware of post #7 and #8

[kiwipiper]

Hopefully this Topic is still alive as I am really keen to do some experimenting with USB.

I have looked at all the posts and haven't found any refering to my problem.

I am using the 18F4550 pic, Picbasic Pro 2.50 and MicroCode Studio Plus 3.0.0.5

When I compile it stops on Line 81

Line 81: UCFG var byte EXT ' include UCFG register... Yeah Melabs didn't (
Line 82: ucfg = %00010100 ' enable internal USB pull-up, Full speed USB

With the following Error Message:

ERROR Line 81: Redefinition of VAR. (USBDemo.pbp)

I notice that when I paste the code from mister-e's zip file into MicroCode Studio it changes the case of line 82:

Line 81: UCFG var byte EXT ' include UCFG register... Yeah Melabs didn't (
Line 82: UCFG = %00010100 ' enable internal USB pull-up, Full speed USB

the ucfg is now in Capitals, I don't know if this has anything to do with it?

[semiuniversal]

Hi mister_e & all who have contributed. I am quite new to PBP and this is my first post to this list. I just found this demo a week ago, read the thread, ordered the parts, assembled a proto board on Saturday and - (insert Windows USB Device da-dink! sound) it worked FLAWLESSLY, the first time. I am either lucky standing on the shoulders of giants - but oh, my, what a good feeling.

I have been tinkering incessantly since then.
Thank you for giving me super powers.

[skimask]

Hi mister_e & all who have contributed. I am quite new to PBP and this is my first post to this list. I just found this demo a week ago, read the thread, ordered the parts, assembled a proto board on Saturday and - (insert Windows USB Device da-dink! sound) it worked FLAWLESSLY, the first time. I am either lucky standing on the shoulders of giants - but oh, my, what a good feeling.

I have been tinkering incessantly since then.
Thank you for giving me super powers.

Take my advice...Give out while you still can...
I have lost countless hours of sleep playing with USB and that demo, spent untold amounts of money, not to mention ticked off the wife numerous times...

Seriously though...Good game...
I wish other Noobs would take that as an example...especially the part about 'reading the thread'....