Re: [Contiki-developers] clarification on the energest formula of contiki

[Marcus L. <mar...@gm...>]

The numbers correspond to the supply voltage (3 V), current consumption with
radio listening (20 mA) and ticks per second for the rtimer (4096 rticks/s)
which is used for measuring time in energest. The rticks/s is in the latest
Contiki version 8192 rticks/s (I think). You can check that in rtimer.h
IIRC, or by printf("rticks/s: %lu", RTIMER_SECOND);

Energest does not take transmission power in consideration, only time, so
you will not see any difference in energest if you change it. If you have a
static case, as in not changing the TxP from time to time, then you can use
the current consumption found in the CC2420 datasheet (between ca 10 mA to
ca 17.5 mA).

Best regards,
Marcus Lunden, SICS



On Sat, Aug 28, 2010 at 14:05, <
con...@li...> wrote:

> Message: 3
> Date: Fri, 27 Aug 2010 22:13:21 +0000
> From: Katerina Argyrou <kat...@ho...>
> Subject: [Contiki-developers] [Contiki-Developers] clarification on
>        the energest formula of contiki
> To: <con...@li...>
> Message-ID: <COL...@ph...l>
> Content-Type: text/plain; charset="iso-8859-7"
>
>
>
>
>
> Dear all,
>
> I would like to ask some questions regarding the energy consumption
> calculation in Contiki OS.
>
> Taking the crash course presentation for Contiki, there is a formula for
> the calculation of the listening component energy consumption,
> value*3*20/4096/runtime, for the TMoteSky. Please can someone explain to me
> as to what the numbers 3,20 and 4096 stand to?
>
> Moreover, in the Cooja Simulation, we can tune the transmission range of
> the nodes. By changing the transmission range what is expected in the values
> of the energy consumption? What should I do to change the transmission range
> of the TMoteSky in order to see a change in the power consumption?
>
> Thank you for your assistance,
>
> Regards,
>
> Katerina
>