Todd Bailey wrote:

> Hi there.
>
>  I know the USB dragon keeps getting slayed over and over again on 
> this mailing list, but I finally got contracted to make a device which 
> interprets some simple user data (switch closures, mostly) and sends 
> them to a PC at a really slow (8kbits per second would be more than 
> sufficient) data rate.
>  The client wants the project done with USB, and honestly, I've been 
> remiss in not taking it upon myself to figure out that particular 
> protocol before now.
>
> I guess the questions I have for you wizards are:
>
> 1.) I'm inclined to use one of the PIC18F parts with a hardware usb 
> transciever, although I've seen it done in examples with software and 
> an external transciever IC.  Any reason I would want to use the two 
> chip solution?
>
> 2.) I'm getting it together, slowly, from datasheets and the Microchip 
> docs.  Can any of you recommend a good (better) resource (web page, 
> book, source code, etc) for a simple USB project AND/OR usb theory of 
> operation?  Seems like there's a lot of arbitrary handshaking and 
> protocols that go on in USB communication.
>
>  Any pointers you guys had would be great.  You've always steered me 
> right before -- I hope these questions aren't too remedial or 
> understudied.
>
> Thanks in advance,
>
> Yours,
>
> Todd
>
>
While using a USB PIC seems like best solution, the easiest solution is 
to use the FT232B AND a simple serial PIC, such as an F88. That way, you 
can use their free USB Windows driver that works perfectly.

You will get bogged down quickly trying  to do this by the specs. My 
printed copy of the USB 2.0specs is 2  2" notebooks thick.
Microchip makes fooling with the USB PICs a tough job.

I'm not saying you can't do it, but its a lot like teaching yourself 
brain surgery and  practicing on the closest available brain (yours).

--Bob

-- 
Note: To protect our network,
attachments must be sent to
attach@engineer.cotse.net .
1-520-777-7606 USA/Canada
http://beam.to/azengineer

-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist