On Thu, 10 Jul 2003, Alex Kilpatrick wrote:

> > >> I'm using the CCS compiler.  The code looks like this:
> > >>
> > >> Output_low(PIN_A1);
> > >> Delay_ms(200);
> > >> Output_high(PIN_A1);
> >
> > Wouldn't you need a delay after the output high, so you can
> > see the led is on?
> >
>
> No, the anode of the LED is connected to the PIC.  The cathode is
> connected to +3.

Matters not.  Here is what you're doing:

Turn LED on for 200ms
Turn LED off for 1uS
Turn LED on for 200ms

See a problem there?

> I generally do this, since PICs can sink more current than they can
> supply, right?

Some can, some cannot.  Check the data sheet.  But it's immaterial if you
are not trying to run 20-25mA to the LED.  If you have a current limiting
resistor in series with the LED to less than 20mA, then who cares whether
the pin can do 20 or 25mA in that direction?  Having said that, either way
is fine.

Dale
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