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Re: Low-power device recommendation

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http://microchip.com/

choose, they are sub 5$

Pozdrawiam.
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Re: Low-power device recommendation
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You might want to take a look at the Ubicom 2022. I think it can do all
this (with exception of the interpreters for JAVA / PERL) with it's
internal flash and RAM for some $7. You only need to add a crystal. It
does have a power save mode that slows down or stops the CPU while a
timer can wake it.

They offer an upgrade path to the 3023 that is much more powerful but
needs more external components.

See www.ubicom.com

-Michael

Re: Low-power device recommendation

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At what latitude are you ? That will determine the height of the sun
in the winter and thus the number of hours of daylight and the
atmospheric losses (airmass). What are the weather conditions in the
winter ? If there is a lot of clouds in the winter months, the solar
cell output will drop even further. Thus you may need backup power for
weeks or even a month. Thus, the average power consumption needs to be
extremely low.
 
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If this is a stand alone device, what do you need the Ethernet for ?
Such high speed devices consume a lot of power.

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So this is not a stand alone device after all ?

Why not run the power over ethernet or take it from the RS-232
handshake lines (assuming your system runs on a few milliamps).
 
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If those are the requirements, then the system could be powered off
for 99 % of the time to save power. Thus, you need a system which can
go into deep hibernation and wake up with an external interrupt, such
as a CMOS clock once a second or you need an OS that boots in much
less than 100 ms if you do a restart every second.

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This depends on your environment requirement.

If plenty of power would be available, it would be quite simple to
keep the component and cabinet indoor temperature 5-10 degrees above
the ambient temperature (even when a warm wet wind rapidly increases
the temperature). This will prevent condensation on the components and
you can use a box with holes in the bottom to ventilate the box and
get rid of humid air when the temperature drops. With sufficient power
you can even keep the indoor temperature above 0 C (since some
components are not specified for subzero temperatures).

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You must either do something about your power supply or rethink the
division of labour in the system, e.g. transmit the raw measurements
directly from a system with extremely low power consumption and do any
hard processing in a system with more resources.

Paul
 

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