Remember that those pins are made to control a keypad so they put
some pull-up resistors to make the scanning routine, and there´s 3.3V
because is a CMOS.
I suggest to read the samples of keypad.c and button.c , this samples
explains a little bit how to works the GPIO Map, and another
documentations that you should read is the "EP9301_user_guide" , is
about the cirrus logic proccesor more specifically the chapter
21 "GPIO Interface".. whith all this stuff you could change the DIO
pins to output or inputs, even the LCD pins.
best regards,
sergio
--- In "linna_lisa" <> wrote:
>
> Why would there be 3.3V on inputs for the TS-7200? I would think
> with a pull up resistor it would be less than 3.3. And if it is
just
> from an internal pull up and it's 3.3 if nothing is connected,
> wouldn't I short something if I put gnd on it?
>
> --- In Kevin Cozens <kevin@> wrote:
> >
> > evil666demonic wrote:
> > > Is it possible that they are coming up as inputs, and that the
> voltage
> > > we are seeing is really just from the internal pull-up
resistors
> on
> > > the DIO? This would explain why you read ~3.3V on those pins at
> > > startup. Dangerous indeed if they attempt to source current,
> > > especially in my case.
> >
> > It is possible. I have seen microcontrollers that come out of
reset
> with the
> > I/O pins set to input with weak pull-ups enabled.
> >
> > --
> > Cheers!
> >
> > Kevin.
> >
> > http://www.ve3syb.ca/ |"What are we going to do today,
> Borg?"
> > Owner of Elecraft K2 #2172 |"Same thing we always do,
Pinkutus:
> > | Try to assimilate the world!"
> > #include <disclaimer/favourite> | -Pinkutus & the
Borg
> >
>
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