Hi, Janos. Thank you once again for your reply. I didn't know that stack. I've been using only TOSSIM. But accomplishing what you said would cause to port the whole stack, right? I was just interested on LPL.
Got to know more about this stack. Kind regards, Pedro Nunes On Tue, Jun 1, 2010 at 2:34 AM, Janos Sallai <[email protected]>wrote: > Pedro: > > Why don't you port the rf2xx stack (tos/chips/rf2xx) to TOSSIM? The code is > organized such that only the lowermost layer is transceiver-specific. The > transceiver-specific driver layer is responsible for powering on and off the > radio, sending packets, downloading received packets and > timestamping/synchronization. Everything else, including LPL, is implemented > in a transceiver-independent manner in upper layers. > > Janos > > On Mon, May 31, 2010 at 8:10 PM, Pedro Nunes <[email protected]> wrote: > >> 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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