You meant cc2420? In fact , you can take a look at the code of CC2420Radio
module. It transmits how many bytes your ask it to transmit.

On 3/31/08, David <[EMAIL PROTECTED]> wrote:
>
> Do you know if this applies to the cc2400, or where I can look this up?
>
> Thanks,
>
> David.
>
> On Mon, Mar 31, 2008 at 10:54 AM, SANG Junjun <[EMAIL PROTECTED]> wrote:
> > I think it depends on the radio.
> > Because some radio can only send/recv a fixed size of packet, for
> example
> > nRF905.
> >
> >
> > On Mon, Mar 31, 2008 at 3:06 PM, Kevin Klues <[EMAIL PROTECTED]> wrote:
> >
> >
> > > If you call send() with a length of 2 bytes, only two bytes will be
> > > transmitted over the air.  The TOSH_DATA_LENGTH paramter basically
> > > determines the maximum size of the payload you could ever send and
> > > receive.  Essentially, it is used to define the size of the data
> > > portion of the message_t struct used to hold messages on your mote.
> > > The length passed to send() is stored in the header portion of
> > > message_t, and when the message is being spooled out over the radio,
> > > theis length field is read to determin how many of the bytes stored in
> > > the data portion of the message should actually be sent.
> > >
> > > Kevin
> > >
> > >
> > >
> > >
> > > On Sun, Mar 30, 2008 at 11:37 PM, David <[EMAIL PROTECTED]> wrote:
> > > > Hi list.
> > > >
> > > >  I've taken a look at tep111 and tep126, but there's something which
> > > >  isn't clear to me from the teps.
> > > >
> > > >  Are the packets transmitted over radio a fixed length or variable
> > > >  (based on requested payload length)?
> > > >
> > > >  eg, if you leave TOSH_DATA_LENGTH at 28, but send a payload of 2
> > > >  bytes, will the other 26 bytes worth of payload still be sent over
> > > >  radio?
> > > >
> > > >  I'm asking because one of my apps needs to send as small as
> possible
> > > >  packets (reduce battery usage, and to hog the radio freqeuncy for
> as
> > > >  short as possible). However, I would like the app to still be able
> to
> > > >  receive larger packets. Otherwise all the apps in the mote network
> > > >  need to have the smaller TOSH_DATA_LENGTH, which is bothersome.
> > > >
> > > >  Any insights on this subject?
> > > >
> > > >  David.
> > > >  _______________________________________________
> > > >  Tinyos-help mailing list
> > > >  [email protected]
> > > >
> > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
> > > >
> > >
> > >
> > >
> > > --
> > > ~Kevin
> > >
> > >
> > >
> > > _______________________________________________
> > > Tinyos-help mailing list
> > > [email protected]
> > >
> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
> > >
> >
> >
> >
> > --
> > Best Regards,
> > SANG JUNJUN
> > http://www.tinysys.cn/
> >
> _______________________________________________
> Tinyos-help mailing list
> [email protected]
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>



-- 
Renjie Huang
Sensorweb Research Laboratory
http://sensorweb.vancouver.wsu.edu/
Washington State University
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