Thanks. Anyone else wants to share some experience implementing microsecond ftsp on TelosB?
-Xiaohui Liu On Thu, Nov 15, 2012 at 3:49 PM, Janos Sallai <[email protected]>wrote: > You will probably have to change the clock source (change T32khz to > TMicro). I'm not familiar with the code, so I can't tell you where this has > to be done in the code. > > Also, you'll have to prevent the MCU from sleeping, because the TMicro > clock stops when the mote goes to sleep. > > Janos > > > On Thu, Nov 15, 2012 at 2:39 PM, Xiaohui Liu <[email protected]> wrote: > >> Hi, >> >> Thanks again. Still one question in line. >> >> On Thu, Nov 15, 2012 at 3:35 PM, Janos Sallai < >> [email protected]> wrote: >> >>> Hi, >>> >>> > So essentially, ftsp only works with cc2420x stack, not cc2420. >>> The cc2420 stack has a timestamping bug, so it won't work well. >>> >>> > What are the changes to the default cc2420 stack if the fix is to be >>> ported to it? >>> I can't tell that. I found the cc2420 stack to be very complicated. >>> Instead of trying to figure out how to fix the timestamping bug, I wrote a >>> complete new stack from scratch. >>> >>> > I find something under $TOSDIR/platforms/telosa/chips/cc2420x/ and >>> $TOSDIR/chips/cc2420x, but not sure which files to look at. >>> The file that contains the cc2420x timestamping implementation >>> is tos\chips\cc2420x\CC2420XDriverLayerP.nc. >>> >>> >>> > Provided that the fix solves the timestamping issue, what else has to >>> be changed to make microsecond ftsp work with cc2420 stack? >>> If you can fix the timestamping issue on the cc2420 stack, then FTSP >>> should work correctly. >>> >> 32khz and millisecond ftsp should work. What about *microsecond* ftsp? >> What changes are necessary? >> >>> >>> >> > BTW, can you please also help answer my previous >> > question<http://mail.millennium.berkeley.edu/pipermail/tinyos-help/2012-October/055927.html> >> > related >>> to timestamping? >>> That question is related to the cc2420 stack, so I can't answer this. I >>> more than happy to answer questions related to the cc2420x stack, though. >>> >>> Janos >>> >>> >>> >>> >>> >>> On Thu, Nov 15, 2012 at 2:12 PM, Xiaohui Liu <[email protected]> wrote: >>> >>>> Hi, >>>> >>>> So essentially, ftsp only works with cc2420x stack, not cc2420. >>>> >>>> What are the changes to the default cc2420 stack if the fix is to be >>>> ported to it? I find something under >>>> $TOSDIR/platforms/telosa/chips/cc2420x/ and $TOSDIR/chips/cc2420x, but not >>>> sure which files to look at. >>>> >>>> Provided that the fix solves the timestamping issue, what else has to >>>> be changed to make microsecond ftsp work with cc2420 stack? >>>> >>>> BTW, can you please also help answer my previous >>>> question<http://mail.millennium.berkeley.edu/pipermail/tinyos-help/2012-October/055927.html> >>>> related >>>> to timestamping? >>>> >>>> Your help is sincerely appreciated. >>>> >>>> -Xiaohui Liu >>>> >>>> >>>> On Thu, Nov 15, 2012 at 2:12 PM, Janos Sallai < >>>> [email protected]> wrote: >>>> >>>>> >>>>> There is weird bug in the timestamping code in the cc2420 stack. >>>>> Sometimes packets get timestamps that should be associated with a >>>>> different >>>>> packet. A few people tried to fix it, yet unsiccessfully. That was the >>>>> primary reason why the cc2420x stack was created. >>>>> >>>>> Janos >>>>> >>>>> >>>>> On Thu, Nov 15, 2012 at 10:48 AM, Xiaohui Liu <[email protected]>wrote: >>>>> >>>>>> Hi everybody, >>>>>> >>>>>> I'm working on a TDMA protocol which requires high precision, even >>>>>> 32khz ftsp does not work for me. I can get microsecond precision if >>>>>> cc2420x >>>>>> stack is used instead of the default cc2420 based on the discussions like >>>>>> here<http://mail.millennium.berkeley.edu/pipermail/tinyos-help/2011-April/050745.html> >>>>>> and >>>>>> here<http://ftsp%20microseconds%20synchronization%20usign%20telosb/>. >>>>>> However, there are many changes of the default cc2420 driver I made, so >>>>>> it's much easier for me to stick to cc2420 than to apply all changes to >>>>>> cc2420x. Is microsecond-level ftsp implemented on TelosB using default >>>>>> cc2420? If not, what changes are necessary to have it? Thanks for any >>>>>> hint >>>>>> in advance. >>>>>> >>>>>> -Xiaohui Liu >>>>>> >>>>>> _______________________________________________ >>>>>> Tinyos-help mailing list >>>>>> [email protected] >>>>>> >>>>>> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >>>>>> >>>>> >>>>> >>>> >>> >> >
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