I checked the voltage on the input pins and found that they're 3.3V
so it's a definite '1'. I have nothing connected to it so it's
coming from somewhere else on the board for some reason.
-Confused
--- In Michael Schmidt <> wrote:
>
> linna_lisa wrote:
> > Hey,
> >
> > I'm using PortB as DIO with the direction register set up as 0x0F
so I
> > can use the first 1-4 as outputs and 6-9 as inputs (pin 5 is
ground).
> > The outputs work fine but when I'm trying to use the inputs all
the
> > pins are high even though they shouldn't be. For a while I was
trying
> > to figure out why my (simple) code wasn't working, then I put a
few
> > print statements in to see where it was hanging up and found it
was
> > going to a part of the code which was based on one of these
inputs
> > being high. I knew the input shouldn't be high but just to make
sure i
> > took out all the connections to verify it couldn't possibly be
coming
> > from my circuit.
>
> > With nothing going to any of the inputs the pins are
> > a logic '1', which must be coming from somewhere else on the
board.
>
> It sounds like there is an internal pull-up resistor on the EP9302
GPIO
> pins. Typically this will be a very weak pull-up, so you will only
see
> the effect when the pin is configured as an input with nothing
connected.
>
>
> ______ Best Regards,
> |__ __/ Michael Schmidt
> || Software Engineer
> ||echnologic Systems (EmbeddedARM.com)
> || (480) 16610 East Laser Drive #10
> |/ 837-5200 Fountain Hills, AZ 85268
> http://oz.embeddedarm.com/~michael
>
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