> Van: Michael Rigby-Jones <mrjones@NORTELNETWORKS.COM>
> Aan: PICLIST@MITVMA.MIT.EDU
> Onderwerp: Re: Two pins joined: One input, other output
> Datum: dinsdag 18 mei 1999 13:17
>
> > > Hi all!
> >
> > Hello Gabriel,
> >
> > >    I have a question for all of you:
> >
> > >   I have to connect one 16F84 to a line of an external circuit, wich
is
> > waiting for
> > > receiving 255 bits from the 16F84. When this is done, the external
> > circuit will reply
> > > to the 16F84 with information, and then begins the loop begins again
and
> > again.
> >
> > >    May I connect two lines of the 16F84 (eg.: RB0 as int, and RA0)
one
> > being
> > > configured as otuput and the other as input ?
> >
> > Yes.  No problem. Oki-Dokie.
> >
> > >    Would the Pic get burned ?
> >
> > No. Nope. No way.
> >
> > One thing though ... I suspect that that line RB0-RA0 will be the line
> > that
> > goes to the other device ?  It's, I hope, not used as a bi-directional
> > line
> > ?  Otherwise you will have the output of the other device linked to the
> > output of you PIC, and that's not allowed ...
> >
> > By the way:  Why would you want to generate a interrupt from a signal
you
> > are creating yourself (RA0 -> RB0) ?
> >
> > Greetz,
> >   Rudy Wieser
> >
> It sounds to me as though Gabriel wants to perform half duplex comms over
a
> 1 wire link.
>
> Thats OK, but when transmitting, you will have to disable interupts, and
> when receiving, you will have to tri-state your transmit pin (RA0).
>
> Regards
>
> Mike Rigby-Jones

Hello Mike,

  What you are describing is what I was thinking. But I wanted to let
Gabriel answer the question, resulting in a more serious question, namely
"Is it allowed to connect two _outputs_ to each other".  Wich You / I /
Someone could have pointed out to him as being hazardous ...  As you have
done :-)

Next question could be : "Why connect two I/O -pins of the same device to
each other, when one pin can be switched between In and Output" ....

Greetz,
  Rudy Wiesr