PIC18F14K50 and USBin

[iw2fvo]

Hi Derrel,
I would like to use the USB connection to the PC for the first time since I do not have the serial port available to me anymore.
I am asking if there is a complete sample program that shows me everything on the USB usage to exchange data to and from the PC.
Are there some hardware advices ? or just use d+ and d- to the PIC ?
The pic is the 184550 and the compiler is PBP 2.50.
Thanks in advance for the assistance on the matter.
Best regards,
Ambrogio IW2FVO

[Darrel Taylor]

To replace a COM port with USB, you'll want to use the CDC protocol.

Start with this thread ...

USB CDC Communications for Dummies!
http://www.picbasic.co.uk/forum/showthread.php?t=5806

[iw2fvo]

Thanks Derrel,
I red a lot of posts as indicated.
I am asking if there is a "final summary "available in which the final hardware and software configuration is described.
In my personal case I shall use the 18f4455 device and the crystal oscillator that could be 20 Mhz or 4 MHz. No bus power will be used.
What will be the configuration set up ? ( include, define ... etc )
What is the program to callup every cycle in my PBP program to comunicate and to receive USB data?
I am sorry but reading all the above posts I still not have a clear understanding.
Thanks for any help.
Best regards,
Ambrogio
iw2fvo

[ybosco]

Start with this thread ...

USB CDC Communications for Dummies!
http://www.picbasic.co.uk/forum/showthread.php?t=5806

I have to note that that thread doesn't write anything useful about clock settings. The line "DEFINE OSC 48" looks very naively. :-) It is not enough.

By the way I managed partly to solve my problem. I found that if I set the system clock as high as 48 MHz then the CPU functions unstable. I got some other problems with another type of operations besides the USB interface.

Now my setting are the following:

• clock frequency- 12 Mhz;
• 4xPLL -enabled;
• CPUDIV=10;

That is the system clock is 16 MHz and USB clock is 48 MHz.
But I had no time to check USB operations at these conditions. I'll check and will report lately.

[mackrackit]

I have to note that that thread doesn't write anything useful about clock settings. The line "DEFINE OSC 48" looks very naively. :-) It is not enough.

Maybe it would help if you read the whole thread, or at least to post #14
http://www.picbasic.co.uk/forum/show...8359#post68359

And the data sheet is VERY helpful too.

[ybosco]

And the data sheet is VERY helpful too.

Of course, it is very helpful!

Still not checked USB with new clock settings... It might happen tonight.