Hi Jagan,

We recently submitted a paper for publication detailing some of these
operations, but they were taken on a mica2.  We're currently working on
taking some of the measurements you refer to on a tmote.  We plan on
measuring power consumption on mica- and tmote's for various packet sizes
soon (maybe this week), to determine the power consumption per transmitted
byte.  We haven't measured LED's, as they aren't expected to be on at all
during a normal operation so won't affect our deployment.  Also, for any
given operation, the power consumption is all over the place, as you can see
from the example plot attached of a mica2 AT45DB flash write operation.
Although this can be averaged out over time, I don't have those numbers
available for anything specific on a tmote.

I happen to only have mica2 power consumption graphs available at this time
on my computer.  In the future, when we take further measurements, I'll post
the plots of power consumption vs. time for tmotes.

-David

-----Original Message-----
From: jagan nath [mailto:[EMAIL PROTECTED] 
Sent: Saturday, May 06, 2006 9:06 PM
To: David Moss
Cc: [email protected]
Subject: Re: [Tinyos-help] RE: Power consumption in motes


Hi David,
Looks like u have put in lot of effort in power measurement of motes.
I have developed an application on the tmotes, that does dutycycling
of the radio and most of the time is in an idle state ( as required by
the application).Now I want to know how long will my batteries last  
(its OK even if I get a rough idea)

 I have the following query regarding power measurements on motes,

1. Is there any document published whcih indicates the exact power
consumption of
tmotes for the following ,
   - Microcontroller operation
   - Radio Power consumption for tx/rx a bit(or TOS packet)
   - various other operations like LED oN etc
   - flash read/write
2. ur mail indicates that u have measured all the operations above,
could u please let us know the values

regards
jagan





On 5/6/06, David Moss <[EMAIL PROTECTED]> wrote:
>
> Hi Krisakorn -
>
> Are you asking about the actual method used to collect the data, or how to
> actually get the power set so low on the mote?
>
> To measure, I used a 2-probe DAQ sampling at 50 kSps, measuring across a
> 1-ohm resistor connected in series with the battery. The 50 kSps provided
> enough resolution to detail individual operations on the mote - i.e. radio
> on/off, receive, transmit, flash read/write, timer fires, etc.  For the
duty
> cycling power measurements, one duty cycle period was measured and
processed
> in Matlab to produce the results.
>
>
> To get the power low on the microcontroller, I connected
HPLPowerManagementM
> in with my app and called HPLPowerManagement.enable() on start.  That
knocks
> the power way down automatically - when the mote isn't doing much, it
won't
> be consuming much.
>
> Then the other thing you have to worry about is turning off the radio.
The
> CC1000 components provides low power duty cycling, which was used to
obtain
> the results.  I forget which component exactly you call to change the duty
> cycling rate.. it's probably in one of the help docs.
>
> On a CC2420 radio, when you turn off the radio by calling
> SplitControl.stop() in CC2420Control (I think), the radio really turns off
-
> you get about 0.102 mA current, which is consumed mostly by the
> microcontroller itself.  But when you turn off the CC1000 radio through
the
> same method on a mica2/2dot, you end up getting around 0.960-some mA - 9
> times more power consumption.
>
> This is my next thing I'll be working on here - I believe the CC1000
radio,
> when turned "off", still has its crystal oscillator and bias running,
which
> consumes a total of 800+ uA.  The crystal oscillator and bias can and
should
> be both be turned off to achieve similar power characteristics as the
CC2420
> motes.  Plus, adding in the features of Boomerang onto a CC1000 radio, as
> far as netsync and everything goes, should allow a network to obtain much
> lower power characteristics than the CC1000 low power duty cycling.
>
> -David
>
>
> -----Original Message-----
> From: Krisakorn Rerkrai [mailto:[EMAIL PROTECTED]
> Sent: Friday, May 05, 2006 12:34 AM
> To: [EMAIL PROTECTED]
> Subject: Power consumption in motes
>
>
> Hi David,
>
> I have seen your post in TinyOS help list regarding the measurement of
> power consumption and duty cycle. Could you please explain me how you
> manage to get this power consumption? Thank you so much.
>
> Regards,
> Krisakorn
>
>
> _______________________________________________
> Tinyos-help mailing list
> [email protected]
> https://mail.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
>

<<attachment: AT45DB_flashwrite.jpg>>

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