Urs Hunkeler ha scritto:
> Hi Francesco,
> 
> You could measure the voltage of the batteries and use this value in
> your further calculations (I think VoltageC gives you the current voltage).

Ok, thank you for your tip! :) Tomorrow I'll try it!

> It might be possible that some batteries have a higher internal
> resistance than others. If your sensors draw a lot of power, this could
> lead to fluctuations in the supply voltage (which you would not have
> with good batteries or a lab power supply).

My sensor is a strain gauge (a resistor-like) in a Weathstone bridge
with an amp op to amplify the changes of strain gauge, so I think that
the power consumption is very low. In fact, when I measured the power
consumption (Brondi battery pack) with an oscilloscope (or multimeter),
in IDLE state it is ~ 0 mV (or 0 mA).

> If you have an oscilloscope,
> you could measure the voltage at the battery terminals while sampling
> your sensors. I'm not an expert on electronics (MS will know more about
> this), but maybe putting a huge capacity in parallel to the batteries
> might help.
> 
> Cheers,
> Urs

Next week, I will go back to the computer science department and I will
measure (with oscilloscope) the power consumption of node with Duracell
battery pack. Meanwhile thank you very much for your help. About the
huge capacity, what value do I choose?

Greetings,
-- 
Francesco Ficarola <francesco.ficarola_at_gmail_dot_com>
[GPG KeyID: 0xDBA99D92]

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