Thanks Janos, now these stacks seem to have some relevance, see the histograms below:
http://s7.postimage.org/3oh7d6gln/cc2420.png http://s9.postimage.org/qswev86xr/cc2420x.png Miklos, Thanks for the reply but I was referring to timestamping accuracy in Ucmini, so the question was does ucmini needs a separate timestamping stack like cc2420x or does the current implementation of it does not require that since timestamping already works fine on it. Regards, Wasif! On Wed, Jan 9, 2013 at 10:45 PM, Janos Sallai <janos.sal...@vanderbilt.edu>wrote: > Hi Wasif, > > The cc2420x stack should be straightforward to set up with the z1. > Just follow how it's set up on the telos. > > One thing it needs is a fast SPI bit rate. My suspicion is that the > SPI on the z1 is configured with 256 or 512 kbps bit rate, though I > can't confirm this. You might want to take a look at the directory > tos\platforms\telosa\chips\cc2420x\tmicro to see how I have > reconfigured the telos clock subsistem to speed up the SPI. Most > probably, the same has to be done with the z1. Since it has a slightly > different MCU than the telos, the code in that directory will probably > have to be altered a bit to work on the z1. > > Janos > > On Wed, Jan 9, 2013 at 2:28 PM, Miklos Maroti <mmar...@math.u-szeged.hu> > wrote: > > Hi Wasif! > > > > Ucmini uses the atmega128rfa1 chip (and not the cc2420) and it is > > fully supported in tinyos, just type "make ucmini". > > > > Miklos > > > > On Wed, Jan 9, 2013 at 11:55 AM, wasif masood <rwmas...@gmail.com> > wrote: > >> > >> Thanks alot Janos! it seems to work now, it was a clumsy mistake on my > side. > >> Another Questions, make z1 CC2420x doesn't work. Do u ever have any > >> experience with that! and also neither for UCMINI. > >> > >> Regards, > >> Wasif! > >> > >> > >> On Wed, Jan 9, 2013 at 4:25 PM, Janos Sallai < > janos.sal...@vanderbilt.edu> > >> wrote: > >>> > >>> Wasif: > >>> > >>> Regarding setting the backoff values to 1us in the cc2420x stack: this > >>> clearly doesn't work, because the code would schedule an alarm 1us in > the > >>> future, which is simply not possible. By the time the operation of > >>> scheduling the alarm completes, that time instant is going to be in the > >>> past, and the alarm will fire after the counter overflows and reaches > that > >>> particular value again. To put it in another way: backoff values under > >>> (approximately) 200 microseconds are not valid. > >>> > >>> To get rid of CSMA logic altogether, you need to remove the collision > >>> avoidance layer altogether and rewire the stack (CC2420XRadioC.nc) as > I have > >>> described in my previous email. > >>> > >>> Janos > >>> > >>> > >>> On Wed, Jan 9, 2013 at 5:31 AM, wasif masood <rwmas...@gmail.com> > wrote: > >>>> > >>>> > >>>> Hi all, > >>>> > >>>> I am trying to measure the message delay on Telosb platform and now > >>>> comparing the CC2420 stack with CC2420X stack. Below are the two > Histograms > >>>> showing the delay spread of Cc2420 and CC2420X stacks respectively. > The > >>>> experiment is perfromed for around 1 hr at the same time using two > different > >>>> frequency channels. > >>>> For CC2420X I have used the TimeSyncAMSend<TMicro,uint32_t> interface > >>>> and have calculated the delay at the receiver end as > >>>> > >>>> delay = call LocalTimeMicro.get() - call TimeSyncPacket.eventTime(msg) > >>>> > >>>> and for CC2420 Stack, I have used TimeSyncAMSend with Milli sec > >>>> precision and have calculated the delay as : > >>>> > >>>> delay = call LocalTimeMilli.get() - call TimeSyncPacket.eventTime(msg) > >>>> > >>>> in case of CC2420 stack CCA is disabled and for CC2420X stack, I have > >>>> changed RandomCollisionConfig implementatoin in CC2420XRadioP module > in such > >>>> a way that all types of backoff values ( Initial, minimum and > congestion) > >>>> are now just RADIO_ALARM_MICROSEC value (because I couldn't find a > direct > >>>> way to disable it). > >>>> > >>>> Now, what I observe is a bit interesting since the two histograms > show a > >>>> completely different delay behaviors, ie. with the Cc2420X stack the > delay > >>>> ranges between 1 to 13ms, but with CC2420X stack the delay goes from > 70ms to > >>>> 150ms. Is this also what any of you experience or is there something > I am > >>>> missing here? > >>>> > >>>> here are the histograms: > >>>> > >>>> http://s14.postimage.org/55bs7ni0x/Telosb_CC2420x.png > >>>> > >>>> http://s8.postimage.org/8paur8s6d/Telosb_CC2420.png > >>>> > >>>> > >>>> Regards, > >>>> Wasif Masood > >>>> > >>>> _______________________________________________ > >>>> Tinyos-help mailing list > >>>> Tinyos-help@millennium.berkeley.edu > >>>> > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > >>> > >>> > >> > >> > >> > >> -- > >> Wasif Masood > >> > >> _______________________________________________ > >> Tinyos-help mailing list > >> Tinyos-help@millennium.berkeley.edu > >> > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > > > -- Wasif Masood
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