On Thu, Apr 20, 2006 at 09:10:44AM -0500, Mike Hord wrote:
> You have your microswitch connected to the LVP pin.  The PIC isn't
> entering programming mode unless the LVP pin is held low.
> 
> Yes, yes, I know you have LVP turned off, but still, there it is.

Actually, almost... The LVP pin is RB3 on the 16f88, not the RB5 that my
microswitch is connected too.

Of course, you probably are right in that putting RB5 low makes RB3 go
just slighly low enough... Bah.

So where's the handy webpage explaining in excruciating detail what I,
like many before me, screwed up on? :)

Could I just put a 10k resistor from RB3 to ground and be done with it?
Or heck, I can just connect it to the programmer with a jumper like the
rest of the ICSP pins and it should work? If it's disabled, it's only
needed for programming right?

> On 4/20/06, Peter Todd <pete@petertodd.ca> wrote:
> > I've got a minor project using a 16lf88 running at 3V with some LEDs
> > attached to PORTA and PORTB and a microswitch to cycle between display
> > patterns. Dead simple thing, a client just needed a mockup of a bike
> > light. The circuit is equally simple, LEDs connected to ground and the
> > pins, all LEDs setup to consume 5ma (white or red w/ resistor) The power
> > source is two fresh 3V lithium's in parallel. Finally the normally open
> > microswitch is connected between ground and RB5. I have the weak pullups
> > enabled.
> >
> > The problem is that ICSP doesn't work unless the microswitch is pressed
> > *down*. This happens even when the PIC is completely out of the circuit,
> > and the only thing connected is the ICSP pins and my microswitch via
> > jumper cables. (and the capacitor, I just soldered it on directly) This
> > has happened with two seperate PIC chips and seems very reproducable.
> > The programmer works fine on different code, but once I program the
> > firmware in, I simply have to have that switch pressed down for ICSP to
> > work.
> >
> > My quite short firmware is attached. I got everything working for the
> > client, but I'd love to figure out what the root cause of this was.
> >
> >
> > Incidentally, I think this is the first post I've made to piclist about
> > pic chips rather than tricked-out scooters or very large numbers... I've
> > been subscribed for about 6 months I think...
> >
> > --
> > pete@petertodd.ca http://www.petertodd.ca
> >
> >
> > --
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> >
> >
> >
> >
> 
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-- 
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