Hello, Janos. Thank you a lot for your reply - it was very enlightening. Now, I am trying to figure it out how to port that behavior to TOSSIM (since it does not simulate Low Power Listening).
I was trying to port the LPL used by CC2420 but it has a lot of dependencies and therefore porting it would be a pain in the backside, I guess. Maybe creating a new and simplified LPL from the scratch would be the best thing to do? Any idea is more than welcomed! :) Kind regards, Pedro Nunes On Mon, May 31, 2010 at 7:49 PM, Janos Sallai <[email protected]>wrote: > Pedro: > > Take a look at the radio control states on page 43 of the cc2420 datasheet. > Apart from the IDLE state, there are two more low power modes, namely "power > down" and "voltage regulator off". The difference between IDLE and "power > down" is that the on-chip 16Mhz oscillator is turned off in the latter > state. Not surprisingly, the transceiver draws about 1mA less in power down > than in IDLE. On the other hand, it takes about 680us more to start a > transmission or to enter receive mode from power down than from IDLE. > > To answer your question: the tinyos-2.x radio stack actually goes _below_ > the IDLE state in terms of power consumption in LPL mode. In fact, as I > recall, not only the oscillator, but also the voltage regulator is turned > off when the transceiver "sleeps". > > Janos > > On Mon, May 31, 2010 at 1:01 PM, Pedro Nunes <[email protected]> wrote: > >> Hi all. >> >> I dug a little bit on mail archives and I found an old thread where it is >> said that the IDLE state is not implemented on CC2420 radio stack (please >> refer to >> http://mail.millennium.berkeley.edu/pipermail/tinyos-help/2005-December/013742.html >> to >> see the whole thread). >> >> Don't you think it is very strange that a mote only has two states? >> (Sending or Receiving?) >> Why don't use IDLE state where battery could be saved? >> This way, whenever a mode isn't in TX mode (transmitting), then it is in >> RX mode (receiving). Accordingly to MICAz datasheet, RX state has a cost of >> 19.7 mA which is higher than any TX state can be. >> This kind of behavior will lead us to something like: one application that >> sends shorter messages (and therefore is on TX mode for shorter periods of >> time) will spend more energy than an application that sends bigger messages >> (and therefore will be on TX mode for longer periods). Since the former >> application will be on RX mode most of the time it will spend more energy >> than the latter (since receiving a message is heavier than sending one cf. >> MICAz datasheet: >> http://www.xbow.com/Products/Product_pdf_files/Wireless_pdf/MICAz_Datasheet.pdf >> ). >> >> Please, can anyone shed some light here? >> >> Kind regards, >> Pedro Nunes >> >> On Mon, May 31, 2010 at 5:10 PM, Pedro Nunes <[email protected]> wrote: >> >>> Hello all. >>> >>> What are the different states of CC2420 radio stack in TinyOS? >>> >>> Regards, >>> Pedro Nunes >>> >> >> >> _______________________________________________ >> Tinyos-help mailing list >> [email protected] >> https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help >> > >
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