On Sun, Jul 07, 2002 at 06:39:53PM -0500, Rex Byrns wrote:
> Thanks,
>
> I read your excellent article a while back on the 16f628 and bought one, but
> then as my project has developed along, I want to save that one for the next
> project, as it has more IO, etc.
>
> Getting this bit bang to work is turning into a quest, it is getting
> personal.  I should have licked it by now, grrrrr.

Rex,

Trust me, it isn't worth it. See, your time is much much much more valuable
than either the part or the aggravation. Don't have the '628, use it.

>
> I am working on a prototype that will definitely use the USART and MAX232
> one the next version, but lots of work till I get there.

But why spin your wheels when it isn't the ultimate goal? You'll have to spend
some debugging time with the 628 too. No point in doubling your efforts.

>
> I have  a question about ground, do I need a ground wire (-5v,pic) connected
> to pin 5 on the 9-pin din?

Yes. It's a signal ground. Full duplex RS232 requires a minimum of 3 wires:
RX, TX, and GND. And it is pin 5 on the DB9.

>  Or, is it chassis ground (PC)?

Nope. They may be one and the same. However that connection is always made
through pin 5 on the DB9 (pin 7 on the DB25 instead of pin 1: chassis ground)

>
> Thanks again.

No problem.

BAJ

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