No the radio is not turned off by default after sending every message. Even if you have defined LOW_POWER_LISTENING, the radio is turned on and off regularly maintaining a duty cycle. I dont know what RxTxDelay is. It had no mention in the CC2420 datasheet. And I tested experimentally the radio starting time on my micaz motes.... the reults are appended
(you can see that the diff b/w startCommandIssueTime and startDoneTime is always 2ms) (note that the value 2ms is accurate only to the order of milliseconds) Messsage <BlinkToRadioMsg> [nodeid=0x1] [startCommandIssueTime= 252] [startDoneTime= 254] --------------------------------------- Message <BlinkToRadioMsg> [nodeid=0x1] [startCommandIssueTime= 502] [startDoneTime= 504] --------------------------------------- Message <BlinkToRadioMsg> [nodeid=0x1] [startCommandIssueTime= 752] [startDoneTime= 754] --------------------------------------- Message <BlinkToRadioMsg> [nodeid=0x1] [startCommandIssueTime= 1002] [startDoneTime= 1004] --------------------------------------- Message <BlinkToRadioMsg> [nodeid=0x1] [startCommandIssueTime= 1252] -- INSERT -- Messsage <BlinkToRadioMsg> [nodeid=0x1] [startCommandIssueTime= 252] [startDoneTime= 254] --------------------------------------- Message <BlinkToRadioMsg> [nodeid=0x1] [startCommandIssueTime= 502] [startDoneTime= 504] --------------------------------------- Message <BlinkToRadioMsg> [nodeid=0x1] [startCommandIssueTime= 752] [startDoneTime= 754] --------------------------------------- Message <BlinkToRadioMsg> [nodeid=0x1] [startCommandIssueTime= 1002] [startDoneTime= 1004] On Thu, Jun 12, 2008 at 6:23 PM, salvatore galati <[EMAIL PROTECTED]> wrote: > Hi all. > Sorry for my frequent questions. > I'm a student of Informatic Engeenering of University of Pisa. > I'm working with TmoteSky motes and TinyOs 2.x on cygwin. > > I founded a difference between my tossim simulation and realt tests with > motes. > In Tossim simulation the average message transmission time is about 6,8 ms > In TmoteSky the average transmission time is about 10 ms. > > I found in http://csl.stanford.edu/~pal/pubs/tinyos-programming.pdf > that > time to turn on/off the CC2420 radio is about: > > 1.) 0.6ms ------> Turn on the voltage regulator > 2.) X ms (depends on contention) ------> Acquire the SPI bus to the > radio > 3.) 0.86ms ------> Start the radio's oscillator by sending a command > over the bus (0.86ms) > 4.) 0.2ms ------> Put the radio in RX mode (0.2ms) > > so total time to turn on/off radio is about ( minimum value ) 1,66 ms > > My question are : > -- This time is the RxTxDelay ? so after sending a message the radio turns > alway off and then turns on? > -- This time to turn on/off radio is the same for micaz and telosb/TmoteSky > motes? > > If this time is the RxTxDelay--->so dafault value in Tossim "mac" object ( > = 0,18 ms from "opt\tinyos-2.x\tos\lib\tossim\sim_csma.h" ) > is too low respect to this value of 1,66ms , it can be possible that > difference, between average transmission > time in tossim and in motes, is caused by this too low RxTxDelay default > value in tossim configuration parameters for a CSMA link.? > > thanks very much for your answers > > Best Regards > > Bye Salvatore. > > _______________________________________________ > Tinyos-help mailing list > Tinyos-help@millennium.berkeley.edu > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >
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