----- Original Message -----
From: Tony Nixon <Tony.Nixon@ENG.MONASH.EDU.AU>

> > I am using a 16F877 chip, and I am trying to use all of port b as an
input.
> > Right now I am having problems with pin RB6.  The data sheet says it's
used
> > for in-circuit debugging but I have that feature turned off, just like I
> > have low voltage programming turned off.
> >
> > If I turn the input voltages for pins 5,6 & 7 off (0V) at the same time,
RB6
> > manages to go down with the others but within 5 seconds RB6 drifts back
high
> > again, and if I switch either RB5 or RB7, the pin input data gathered is
> > more likely to change than with switching the input at RB6 itself!  I am
> > using a DIP switch and I have tried it in pull-up and pull-down
> > configurations with 4.7k resistors.
> >
> > I am using the uChip Picstart Plus & MPLAB software, it says I have the
LVP
> > and debugging turned off.
> >
> > Am I overlooking something?  I can't find much in the datasheet.

> Are these pins set as inputs or outputs. You seem to want to write data
> to them, but also have switches connected.
>
> It sounds like RB6 is a floating input.

The pin is set as an input.  I'm not sure where I allude to an output, I am
putting the data out to port C.  I can't see why it is floating.  I'm not
trying to write data to them.  I have the tris state set correctly.

I'll try another chip, maybe there is something wrong with it.

Jeff

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