[Tinyos-host-mote-wg] Re: [Tinyos-2.0wg] TinyOS Telecon Notes 8/31/05

[Joe Polastre]

> Phil: I agree. It should take something like 60-80 cycles to compute
> the power state of the mcu. Let's consider the notion of a dirty
> bit. If anything changes in the power state, the dirty bit isset. The
> MCU goes into same state as the last time unless this bit is set. When
> set it recomputes. ... Is this notion something that would be usesful
> for eyes?

Note about Phil's comment:

This won't work if you're using a DMA or other such device that relies
on other hardware components.  It makes setting the "dirty" bit very
difficult.

Besides, 60-80 cycles is at most 20us of computation.  Considering it
takes longer than that for the Atmel to wake up, I don't see a problem
doing the computation.

Martin-- What is going to be the "default" oscillator for mica2 and
micaz?  Seems like using the external oscillator is like shooting
yourself in the foot before you even start.  Does Xbow have any plans
to calibrate the internal Atmel oscillator?  Is there even a reason to
include the external oscillator on the board?  Obviously we don't use
one on Telos/Tmote or Eyes, and there's at least one "micaz clone"
that don't have it either.

-Joe


On 8/31/05, Ben Greenstein <bengreenstein at gmail.com> wrote:
> For some reason Martin's voice sounded like two separate people to me.
> Here's an updated version of the notes.
> 
> 
> On 8/31/05, mturon at xbow.com <mturon at xbow.com> wrote:
> > 
> > 
> > 
> > Ben, 
> > 
> >   
> > 
> > There were only four people in that meeting!  All the ?? comments where
> mine. :) 
> > 
> >   
> > 
> > My main focus was regarding the platform layer notification, with specific
> focus on the flash as an example. 
> > 
> >   
> > 
> > On the micaz, I would like to link the flash power pin to the MCU sleep. 
> I want the flash to be on and available when the processor is awake, and off
> when it is asleep.  I could see this being the case with an on-board
> thermister and other peripherals as well that have minimal (assume zero)
> latency issues (GPIO voltage over single resistor to ground.) 
> > 
> >   
> > 
> > While the timeout strategy we discussed as a good solution for sensors and
> application-level management can work for the external flash, it isn't
> ideal.  On my platform, the flash power pin could draw ~300uA;  I want sleep
> to be ~20uA. 
> > 
> >   
> > 
> > So the suggestion we are pondering is adding a hook to the scheduler that
> only the platform and chip HAL is allowed to intercept: 
> > 
> >   
> > 
> > [scheduler] 
> > 
> > while (1) { 
> > 
> >           do tasks 
> > 
> >           atomic { 
> > 
> >               signal HALPwrMgr.sleep(); 
> > 
> >               __nesc_atomic_sleep(); 
> > 
> > } 
> > 
> >           signal HALPwrMgrHook.wake(); 
> > 
> >   
> > 
> > } 
> > 
> >   
> > 
> > [flash] 
> > 
> > async atomic HALPwrMgr.sleep() { 
> > 
> >     // this must be fast, responsible code – just flip one pin! 
> > 
> >     call HPLFlash.PwrPin.clr(); 
> > 
> > } 
> > 
> > async HALPwrMgr.wake() { 
> > 
> >     if (flash_started) call HPLFlash.PwrPin.set(); 
> > 
> > } 
> > 
> >   
> > 
> > [MCU] 
> > 
> > async atomic HALPwrMgr.sleep() { 
> > 
> >           // all those crazy register checks of timer and adc. 
> > 
> >           // but implemented using HPL calls 
> > 
> > } 
> > 
> >   
> > 
> > 
> > Martin 
> > 
> > __________________________________________________ 
> > Martin Turon   |  Crossbow Technology, Inc. 
> > 
> > ________________________________
>  
> > 
> > From: tinyos-2.0wg-bounces at Mail.Millennium.Berkeley.EDU
> [mailto:tinyos-2.0wg-bounces at Mail.Millennium.Berkeley.EDU]
> On Behalf Of Ben Greenstein
> > Sent: Wednesday, August 31, 2005 1:42 PM
> > To: tinyos2 group
> > Subject: [Tinyos-2.0wg] TinyOS Telecon Notes 8/31/05 
> > 
> >   
> > 
> > Please see the attached notes. Also, I couldn't identify an attendee or
> two, so please correct. Thanks. 
> 
>  
> _______________________________________________
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> 
> 
> 
>

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