thanks Miklos, that is convenient! On Thu, Jan 10, 2013 at 10:23 AM, Miklos Maroti <mmar...@math.u-szeged.hu>wrote:
> Hi Wasif, > > On Thu, Jan 10, 2013 at 10:05 AM, wasif masood <rwmas...@gmail.com> wrote: > > > > 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. > > The atmega128rfa1 (the MCU in the ucmini) has a built in time capture > register which is based on a 62.5 KHz 32-bit low power timer that is > always running. No extra configuration is necessary, everything works > by default. > > Miklos > > > > > 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 > -- Wasif Masood
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