[Tinyos-help] sleep and current consumption for tinynodes

[Alan Marchiori]

Hi Jacob,

I really don't have an answer for you; more of an idea.  If it is the
same flash as used on TelosB you need to send it a command over the
SPI bus to put the flash into low power sleep.  I thought TOS did this
during boot but possibly because you are using the null app or removed
all SPI support it is not sending the sleep command.

I would test by removing the flash chip (or cut vcc) from the mote and
if that doesn't work keep removing other chips until the current
drops.  :)

LPM4 should be less than 500uA.  Unless the mote is waking up shortly
after going into LPM4.  I think the only think the only thing that
wakes the mp430 from LPM4 is an external interrupt.

Alan

On Thu, Jul 9, 2009 at 3:37 PM, Jacob Sorber<jacob.sorber at gmail.com> wrote:
> I don't know if there's anyone out there looking into this problem,
> but I thought I would report on what I have found so far.
>
> Disclaimer.  While I understand the tinyos CPU power management scheme
> at a high level, I really don't know enough about the msp430 to know
> if the implementation details (including the inline assembly) is
> correct.
>
> Anyway, I went into chips/msp430/McuSleepC.nc and forced it into
> various power states (meaning that I manually set the powerState
> variable in computePowerState();  Since I'm running the Null app, and
> just trying to verify that the power managment works, this seems like
> a reasonable thing to do.
>
> If I set it to LPM4 the mote is consuming ~510uA.
> If I set it to Active it consumes ~1.6mA
>
> Further, when I don't force it, it seems to be correctly choosing
> LPM4, but I can't seem to get rid of that last 500uA.  I'll keep
> looking at it, but if anybody out there has any advice,
> recommendations of things to try, etc, please send them along.  I'm
> hunting blind at this point.
>
> Is there some other component that would draw 500uA, if carelessly
> left on?  I'm using the Null app, so there's no Radio or Flash code
> included in the app.c file.
>
> I know I can get the power consumption down in TinyOS 1.x, but I
> REALLY don't want to go back to that.
>
> Thanks,
> Jacob
>
> On Mon, Jul 6, 2009 at 4:20 PM, Jacob Sorber<jacob.sorber at gmail.com> wrote:
>> I don't know if anyone has had this problem, but it seems in tinyos
>> 2.1 that my tinynode 584s are not sleeping by default.  For example,
>> when I program a tinynode with the Null sample app (radio off, no
>> Leds, no computation, no tasks), it draws about 500-600uA, not the
>> 0.2uA I expected.
>>
>> In TinyOS 2.0, I seem to remember this happening automatically.  If
>> there's something I have to do to turn on MCU power management, I
>> would love to know what it is.
>>
>> Thanks,
>> Jacob Sorber
>>
>
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