>
> *The function digitalRead returns the value of the pin does it not?*
>

This I do not know first hand as I have never used bonescript. What I can
say is that typically, when calling an executable directly from Nodejs (
which is what bonescript uses - Nodejs ), you need to use a callback to
capture the output of that executable *if* you wish to use that value from
within the script.

What I do imagine, as far as how bonescript works. Is that it directly
calls an executable of some sort ( custom, or Linux command ), which then
returns a value depending on which mode the pin is set as. Jason Kridner
should know for sure since he wrote the library, and I could be wrong. I
never really examined his code all that well, before I decided it was not
for me.

*Basically what I ask is, if reading the return value of the digitalRead is
> enough, of should I capture the value of the pin via a callback function.*
>

 Ok, so if bonescript does in fact return a value, and if correct ( without
a callback ), then there should be no problem. You could / should test the
value to make sure it is correct though.

*I am writing a small program where I interchange  the mode of a pin as
> input and output. I am having difficulties doing that.  I am a newbie in
> javascript, but I am wondering if that is possible at all.*
> * Thanks in advance*
>

I have read on these groups from various people that using a single pin (
GPIO - read / write ) is possible. However, I am left wondering in which
case that would be useful. Whatever the case, digitalRead would only work
when the pin is configured as GPIO -> IN.

Two ways I *think* you may be able to do this is using . . .

https://github.com/cdsteinkuehler/beaglebone-universal-io - This would be
slow-ish, but you could call config-pin directly from Nodejs.

or by using pin(s) the PRU's can switch modes for fast. For something like
say a buffer<->external memory. This way would also be far more complex,
but should be vastly faster than using universal-io.



On Tue, Jan 6, 2015 at 3:29 PM, Vasilis Iliadis <[email protected]>
wrote:

> The function digitalRead returns the value of the pin does it not?
> Basically what I ask is, if reading the return value of the digitalRead is
> enough, of should I capture the value of the pin via a callback function.
> I am writing a small program where I interchange  the mode of a pin as
> input and output. I am having difficulties doing that.  I am a newbie in
> javascript, but I am wondering if that is possible at all.
> Thanks in advance
>
> On Jan 6, 2015 2:44 AM, "William Hermans" <[email protected]> wrote:
> >
> > How would you plan on getting the information back from digitalRead if
> not by using a javascript callback ?
> >
> > Also, more information is needed. e.g. what is your program goal ?
> >
> > On Mon, Jan 5, 2015 at 2:38 PM, 'Vasilis Iliadis' via BeagleBoard <
> [email protected]> wrote:
> >>
> >> I am playing with GPIO and digitalRead in bonescript. I noticed that
> although digitalRead is fairly fast the callback function takes a while. I
> am asking the group if I should wait for the callback to be triggered or
> just calling digitalRead is enough!.
> >>
> >> Thanks
> >>
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