[Tinyos-devel] again about the baudrate issue for telos

[Eric Decker]

On Thu, Sep 4, 2008 at 12:16 AM, Andreas Köpke <koepke at tkn.tu-berlin.de>wrote:

> Am Donnerstag, den 04.09.2008, 00:13 -0700 schrieb Eric Decker:
> >
> >
> > On Wed, Sep 3, 2008 at 11:40 PM, Andreas Köpke
> > <koepke at tkn.tu-berlin.de> wrote:
> >         You try to send 115200 at the same time in _both_ directions.
> >         That is
> >         indeed a problem.
> >
> >
> > Why do you say this?  It is full duplex.  And if the interrupt service
> > time wasn't so
> > long it should work.
> >
> >
> > So what are you hinting at?
> >
> >
> > eric
>
> The ISR time is short enough for half-duplex, but too long for
> full-duplex.


The outgoing code I've looked at is pretty short so I don't think that would
be a problem.

However the incoming receive code definitely takes too long.

So I'd say we are agreeing.

eric


>


> >
> >         Am Mittwoch, den 03.09.2008, 18:40 -0400 schrieb Razvan
> >         Musaloiu-E.:
> >
> >         > Hi!
> >         >
> >         > I attached a small application and a Python testing script
> >         that shows that
> >         > 115200 doesn't work reliably for telos. The nesC application
> >         is sending
> >         > packets back to back while the script will accept all the
> >         incoming packets
> >         > and tried from time to time to send some (one at a time).
> >         Using the 57600
> >         > (enabled by default in the application) the acks work
> >         properly. When the
> >         > 115200 is enabled the acks stop working (or they come very
> >         infrequently).
> >         >
> >         > This issue was discussed before [1] but no solution surface
> >         from that. In
> >         > this context I think it would be good to switch to safer
> >         57600 rate for
> >         > now. Is anybody against this? :P
> >         >
> >         > Note: I don't have a Windows TinyOS installation so I only
> >         tested on Linux
> >         > on real machines and VMWare.
> >         >
> >         > [1]
> >
> http://mail.millennium.berkeley.edu/pipermail/tinyos-devel/2008-April/thread.html#2651
> >         >
> >         > --
> >         > Razvan ME
> >
> >         > _______________________________________________ Tinyos-devel
> >         mailing list Tinyos-devel at millennium.berkeley.edu
> >
> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-devel
> >
> >
> >         _______________________________________________
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> >
> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-devel
> >
> >
> >
> >
> > --
> > Eric B. Decker
> > Senior (over 50 :-) Researcher
> > Autonomous Systems Lab
> > Jack Baskin School of Engineering
> > UCSC
> >
> >
>
>


-- 
Eric B. Decker
Senior (over 50 :-) Researcher
Autonomous Systems Lab
Jack Baskin School of Engineering
UCSC
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