What's the input impedance of a PIC input?  How about one on a chip
that's been comprimised or damaged?

Also a thought, does the F84 have the internal PORTB pullups?  Are
they enabled, and maybe you have a weak internal pullup competing
with a weak external pulldown...

Mike H.
>Just come back to PICs after a very long break. Just updating an old
>project, on
>a 16F84. Very simple, just flashes LEDs etc.
>
>Now changed rb6 and rb7 to inputs to read a pair of simple switches, which
>are
>pulled low by 10K res, then switch pulls them high.
>
>I've set to inputs like this....
>
>move to bank 1
>     movlw    b'11000000'
>     movwf    TRISB
>return to bank0
>etc
>
>then read them as
>     btfsc    portb,6
>etc
>
>but when run PIC does not recognise state of RB6 and RB7 -a simple
>voltmeter
>check on them gives approx 1.55 volts when they are not pulled high by
>input
>switch.
>
>Can anyone suggest what is causing this? I think it is something simple and
>I'll
>kick myself when I realise....
>
>Stuart
>
>--
>http://www.piclist.com hint: The PICList is archived three different
>ways.  See http://www.piclist.com/#archives for details.

_________________________________________________________________
Shop online for kids  toys by age group, price range, and toy category at
MSN Shopping. No waiting for a clerk to help you! http://shopping.msn.com

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.