Pic 18f Usb

[Bruce]

Hi Steve,

If you have the PIC being recognized as an HID device, try this. It's real simple, but will allow you to control an LED from VB6 (should also work with VB5) but I don't have that to test it with.

Create your VB code with EasyHID. Open the project, and drop two command buttons on your form. Add this code for your buttons --

Private Sub Command1_Click()
BufferOut(8) = 0 ' LED on
hidWriteEx VendorID, ProductID, BufferOut(0)
End Sub

Private Sub Command2_Click()
BufferOut(8) = 1 ' LED off
hidWriteEx VendorID, ProductID, BufferOut(0)
End Sub

Modify the PBP code created by EasyHID something like this --

PORTB = 0
TRISB = 0

usbinit ' initialise USB...
ProgramStart:
gosub DoUSBIn
PORTB = USBBuffer[7]
goto ProgramStart

Note this doesn't send data, it's just a sit & spin simple app reading USB input, and placing the value received in USBBuffer(7) on RB.

[Tissy]

Bruce, thanks ever so much for taking the time to reply and for starting me in the right direction. Indeed i now have VB talking to the PIC over USB.

Do you have any knowledge of the EasyHID application? Having used EasyHID to set the base code etc, when i look at the device manager, it only shows up as a 'USB Human Interface Device' and 'HID-Compliant Device' and not as i set in the EasyHID maker, such as 'USB LED Controller'.

I was expecting an .inf file or similar to be compiled. Is this something that needs to be done manually? It would be a nice touch to have that when i plug in the device, in the task bar, the name of this device is displayed like any other USB device when connected.

Thanks again for you kind help,

Steve Tisseyre

[Bruce]

Hi Steve,

The information you enter when creating USB framework files with EasyHID is just for the embedded side with a very handy .dll that handles host to function communications.

EasyHID just gives you the USB framework. As far as I know, it does not create a Windows .inf file. That's up to you to create.

If you don't have your own .inf file or HID driver, then Windows will install its own HID drivers, and your new USB gadget is just going to show up with the default Windows name in Device Manager like 'USB Human Interface Device' and 'HID-Compliant Device'.

If you're running XP, look in the Windows input.inf file, and you'll see why. It tries to match the descriptors, VID, PID with existing "certified" manufacturers & hardware. If your new USB gadget isn't in the list, Windows uses the default HID compliant description with generic HID drivers.

Download the Microchip USB framework and take a look at how they setup the .inf & driver files. That will help you understand what's required.

If you plan on making a USB enabled "product", then you might also want to grab a copy of Jan Axelson's USB Complete 3rd edition. It's worth every penny, and gives you details on how to get your USB product/manufacturer name to show up in Windows Device Manager.

EasyHID will get you started, (and really quick I might add), but there's still a lot left to the end user to figure out.

Hats off to Dave at Mecanique for putting in the HUGE amount of time & study required just to give everyone that nifty "free" utility.

[Tissy]

Hi Bruce,

I have now ordered the book as you recommended, i'm sure it will come in very handy.

I have figured out that if you use EasyHID to set the maximum Buffer size to 32, then you can increase the amount of outputs on the PIC that you can set HIGH or LOW. ie the PIC side is odd numbers 1 - 31 and the VB side is even numbers 2 - 32.

ie on the PIC side requires:

PORTC.1 = USBBuffer[23]

where as on the VB side requires:

BufferOut(24) = 1 ' LED on

If i want to use all of PORTA and PORTB, is there an easy way of listing these in the two codes, or do they have to be done seperately? ie:

PIC
PORTA.1 = USBBuffer[1]
PORTA.2 = USBBuffer[3]
PORTA.3 = USBBuffer[5]
PORTA.4 = USBBuffer[7]
PORTA.5 = USBBuffer[9]

VB
BufferOut(2) = 1 ' LED on
BufferOut(4) = 1 ' LED on
BufferOut(6) = 1 ' LED on
BufferOut(8) = 1 ' LED on
BufferOut(10) = 1 ' LED on

Moving on from the switching of outputs HIGH or LOW, how would one send say text from the PIC to a text box in VB. For example, on the PIC, if a certain routine is executed, it sends a command to the VB application which is then displayed in a text window. Or is this getting too advanced for a quick explanation??

Thanks again for you assistance,

Steve

[andresnavas]

Hello. I don't know what happend but my EasyHID only create 4 files:
DESCUSBProject.asm
USBDESC.asm
USBProject.asm
USBProject.pbp

What i doing wrong? why it don't creat the other files like the USB18.c

Thanks for yours help!!!

Please if somebody have any example send it to me at: [email protected]

Thanks!

[Tissy]

andresnavas,

I have sent the reply straight to your personal email address. It would appear that the files aren't generating properly. All i can suggest is check the compilation settings again. If that doesn't work, try installing the application again.

I certainly haven't had any problems like that.

Within the directory you specified in the project settings (default is C:\Program Files\Mecanique\EasyHID\) should see another directory as per your title, such as USBProject. Within that directory is 2 sub directories, one for the VB or C code and one for the Proton or PICBasic code.

I have sent you a zip file containing what you should expect to see for a default VB and PICBasic code using the PIC18F4550 also with all the default settings.

Hope this helps,

Steve

[judy]

Hi all,

Absolutely brilliant thread, a lot of quality info and best of all can be done fast, cheers to all those involved. I am really new to this interfacing stuff, so if I'm asking too much or the newbie stink is unbearable, feel free to tell me to sling my hook.

I was wondering how one would go about changing the HID code provided by Easy HID USB code generator to simply read in up to three pulse width inputs (as far as I know the digital ins on the 18f2455 support this) and up to three analog ins through on board adc (ideally varying between -3 to +3v) simultaneously and as fast as possible, in fact how many samples per second is possible using the HID approach? Sin e.

I would greatly appreciate any help with this/direction to where help should be sought.

Thanks in advanced
Judy

[Demon]

...
Download the Microchip USB framework and take a look at how they setup the .inf & driver files. That will help you understand what's required.
...

Hi Bruce, do you have a link? I did a search on the Microchip site for <Microchip USB framework> and couldn't find a download.

(I'm assuming this is some sort of compile utility that will help Windows XP make a link between the USB device and our EasyHID-generated VB code.)

Robert

[Bruce]

Hi Robert,

The Microchip USB framework files are C18 code for the USB PIC. Look under Development Tools for PIC Demo Boards. Go to the page for the full speed USB board. All files & app notes can be downloaded from that page.

When you run the setup program for the PIC USB demo board it installs the framework files. You'll want to grab all the associated app notes on the same page, and USB loader if you plan on using that.

With PBP v2.46 you use DEFINE RESET_ORG 800h to force user code to start at the proper location when using the Microchip USB loader.

[Tissy]

Is the USB loader so you can bootload the PIC over USB with a new firmware?

[Bruce]

Yes. It's the same USB boot-loader provided with the Microchip full speed PIC USB demo board.