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

Andreas Köpke koepke at tkn.tu-berlin.de
Mon Feb 16 23:24:28 PST 2009


The bottom line of the discussion was very simple: many users seem to be happy 
with 57600 bit/s, especially if packets should travel from PC to mote: the 
telos node can not handle the interrupt load at higher baud rates. But as Phil 
pointed out: due to some long atomic sections in the TinyOS code, this is 
still no guarantee that the packet will arrive at the mote. 

In my experience the reliability of the connection from mote to PC is more a 
serial forwarder issue than anything else. 

Maybe we should take a poll on this. 

Best, Andreas 

Stephen Dawson-Haggerty wrote:
> I don't know what other tests people have run, but at least in my
> experience (all on linux) 115200 seems to have more dropped packets and be
> less stable when you're sending quickly.  I haven't run any micro tests on
> this, though; I'd be happy to if someone has one.  Perhaps the cygwin
> serial is going to be equally unreliable at all rates...
>
> This mail thread seemed to end without resolution, so I'm also curious
> about what happened...
>
> Steve
>
> On Mon, Feb 16, 2009 at 2:09 PM, Philip Levis <pal at cs.stanford.edu> wrote:
> > On Feb 16, 2009, at 1:26 PM, Stephen Dawson-Haggerty wrote:
> >
> >  Everybody seems to have agreed that the default msp430 uart speed should
> >
> >> be 57600-- can somebody in core make the change?  It is definitely much
> >> more reliable at the slower baud rate...
> >>
> >> Best,
> >> Steve
> >
> > Hold on -- I think we went over this a long long time ago, and found out
> > the problem was Cygwin, not TinyOS per se. Can someone summarize the
> > tests that have been run (read/write load, host OS)? The mail thread
> > doesn't seem to have much detail.
> >
> > Phil



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