Hi Wasif, On Thu, Jan 10, 2013 at 10:05 AM, wasif masood <[email protected]> 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 <[email protected]> > 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 <[email protected]> >> 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 <[email protected]> >> > 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 >> >> <[email protected]> >> >> 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 <[email protected]> >> >>> 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 >> >>>> [email protected] >> >>>> >> >>>> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >> >>> >> >>> >> >> >> >> >> >> >> >> -- >> >> Wasif Masood >> >> >> >> _______________________________________________ >> >> Tinyos-help mailing list >> >> [email protected] >> >> >> >> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >> > > > > > > -- > Wasif Masood _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
