On Fri, Apr 25, 2008 at 8:23 PM, Philip Levis <[EMAIL PROTECTED]> wrote:

>
> On Apr 25, 2008, at 2:00 AM, Linas Ramanauskas wrote:
>
> > Hello,
> >
> > Platform: CrossbowTelos (Rev B 2004/09/27)
> > Operating system: TinyOS 2.0.2 (downloaded from CVS 2008.04.23)
> >
> > Is it possible, that after calling "call Send.send(&packet,
> > sizeof(data_t))" that resulted in SUCCESS the event "event void
> > Send.sendDone(message_t* m, error_t err)" is not signaled?
> >
> > I have an application, based on EasyCollection, that takes data form
> > integrated sensors and sends it 4 times per second. There is three motes:
> > base (packet sniffer), root and sender.
> >
> > When mote executes SendMsgTask() and finds flag radioSendBusy TRUE, it
> > toggles red led (it means, packet will not be send). When mote successfully
> > calls Send.send(&packet, sizeof(data_t)), it toggles green led. When there
> > is event void Send.sendDone(message_t* m, error_t err) signaled without
> > SUCCESS in err, mote turns on blue led.
> >
> > Normally the green led is blinking and data is received at PC. If I turn
> > off the root, sending mote starts retransmitting data. During this time I
> > can see red diode blinking few times, this indicates that there is
> > radioSendBusy set to TRUE. So, during this blinking, event
> > Send.sendDone(message_t* m, error_t err) fires and because there was no ACK
> > from root, the blue led is turn on. This is also normal behavior.
> >
>
> Why would no ACK from root cause the blue LED to turn on? That's not the
> semantics of the error_t in sendDone().


As far as I know error_t in  sendDone() just informs if packet was
successfully send over radio, but in scenario described above error_t is
also equal to FAIL if there was no ACK. I can see many retransmissions
before blue LED turns on. Am I wrong?


On Fri, Apr 25, 2008 at 8:25 PM, Philip Levis <[EMAIL PROTECTED]> wrote:

>
> On Apr 25, 2008, at 2:00 AM, Linas Ramanauskas wrote:
>
> > Hello,
> >
> > Platform: CrossbowTelos (Rev B 2004/09/27)
> > Operating system: TinyOS 2.0.2 (downloaded from CVS 2008.04.23)
> >
> > Is it possible, that after calling "call Send.send(&packet,
> > sizeof(data_t))" that resulted in SUCCESS the event "event void
> > Send.sendDone(message_t* m, error_t err)" is not signaled?
> >
>
> This should never happen. It sometimes happens in TOSSIM when you forget
> to configure the radio model such that a node never hears a clear channel,
> but it shouldn't occur in the real world (barring egregious 2.4GHz
> interference, which is very very unlikely).


Here I find out that in close neighborhood there is some government
organizations that uses RF jamming devices. So it explains everything. Very
nice place for WSN developing ;)

Thanks for your answers, Philip
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