On Mon, Apr 18, 2011 at 8:27 AM, Janos Sallai <sal...@isis.vanderbilt.edu>wrote:
> Hey Markus, > > The reason why I have only checked in the micaz version of the cc2420x > stack is that the telos timer subsystem must be reconfigured > "significantly" in order for the microsecond timestamping to work. > If you are using standard interfaces that may be true. But the TelosB h/w timer is actually ticking at 1uis (binary microsecond ticks). The main mis (binary millisecond) timer is being clocked off a 32KiHz clock. The main clocks are shut down when the cpu goes to sleep. > Specifically, we have to make sure two things: a) the SPI bus is fast > enough to download from/upload to the FIFO in real time, and b) that > the SFD is captured by the microsecond counter (vs. the asynchronous > 32khz counter). > > I have the code for this in tinyos-2.x-contrib/vu. Specifically, the > code that configures the timer subsystem in is tos/msp430, and the > altered timer map is in platforms/telosa. > > RADIO_ALARM_MICROSEC can safely be set to 1, since the mote runs close > to 4MHz, which when prescaled by 4 will give a microsecond timer (and > alarm, therefore). For the same reason, RADIO_ALARM_MILLI_EXP should > be set to 10. > > Janos > > > On Fri, Apr 15, 2011 at 5:04 AM, Markus Becker > <m...@comnets.uni-bremen.de> wrote: > > Hello, > > > > I was checking out rfxlink and whether it works on TelosB nodes. I didn't > see > > support in the repository nor someone working on it on the mailing list. > > > > So I got started with it and wired things together for TelosB: > > http://www.comnets.uni-bremen.de/gitweb/?p=mab-tinyos- > > main.git;a=commit;h=3df542e639efcaea007127b28691d45c99768bf9 > > > > rfxlink/TestTransmit compiles for telosb now at least. > > > > I don't know how to calculate the values for RADIO_ALARM_MICROSEC and > > RADIO_ALARM_MILLI_EXP , though. Would someone advise me please? > > > > BR, > > mab > > > > ------------------------------------------------ > > | Dipl.-Ing. Markus Becker > > | Communication Networks > > | Mobile Research Center > > | TZI - Center for Computing Technologies > > | University Bremen > > | Germany > > ------------------------------------------------ > > _______________________________________________ > > Tinyos-help mailing list > > Tinyos-help@millennium.berkeley.edu > > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > > > > _______________________________________________ > Tinyos-help mailing list > Tinyos-help@millennium.berkeley.edu > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > -- Eric B. Decker Senior (over 50 :-) Researcher
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