[Tinyos-help] Any help with computing the energy of the sensors!

[Michael Schippling]

I didn't know about that chip...pretty cool, but will still only
approximate things based on some set of 'ideal' conditions. I'm
sure we've all had the low-battery warning on some device happen
at seemingly random times before full failure...

But there is a nice app-note on using voltage as a charge indicator:
http://www.maxim-ic.com/appnotes.cfm/appnote_number/121

thanks
MS

Jacob Sorber wrote:
> If you aren't afraid of a little hardware work, you can also use a fuel 
> guage IC like the DS2770 from Maxim/Dallas.  That will give you better 
> accuracy, if you really need it.  If you approximate battery energy 
> using voltage, just keep in mind that it is not linear and that it is 
> different for each battery.  You should either check the battery specs, 
> or estimate the curve experimentally.
> 
> Jacob Sorber
> 
> On 1/18/07, *Michael Schippling* <schip at santafe.edu 
> <mailto:schip at santafe.edu>> wrote:
> 
>     If you mean battery energy, you probably can't because there is no
>     provision for measuring current draw. You can approximate it with
>     the battery voltage and knowledge of the discharge characteristics.
>     I also recently suggested measuring the voltage before/during doing
>     something that draws a lot of current.
> 
>     MS
> 
> 
>     paul jhon wrote:
>      > Hello,
>      >
>      > I need to compute the initial energy of the sensors
>      > and its remaining energy at every moment.
>      >
>      > Can you please tell me how to do this in TinyOS2.x?
>      >
>      > thank you so much for your answer.
>      > Paul
>      >
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