Hi! About the different results with different batteries - my guess would be, that the fluctuations arise because of differences in the rate at which the batteries are able to release current (which is a measurement less known than Ah or Voltage). It means, that while one battery under load is still capable of providing the same Voltage, the duracells might be discharging slower and under load capable of giving less than normal Voltage. That is of course if the fluctuations are at the time of some radio or other activity whic uses battery. (Incidentally, that means that the Duracell will serve longer than the other kind of battery, because it conserves power more, while the other battery just floods more power to keep up the constant Voltage under load) At least that is my Guess :)
On Thu, Dec 2, 2010 at 8:11 PM, Francesco Ficarola <[email protected]> wrote: > Michael Schippling ha scritto: >> Yes I believe the IRIS has 10 bit ADCs, so your formula is correct. >> >> I don't know about the IRIS specifically, but in general the Vref >> IS the VCC battery on these boards, so noodling around with software >> settings will probably not make much difference. The one advantage >> here is: if your sensor runs off the same batteries and is ratio- >> metric (some kind of voltage divider) the ratio of Vref to sensor >> will remain constant as Vcc changes. > > Ok, thanks a lot for your help. ;) > >> Interesting about the different kind of batteries. >> Are the Duracells fresh? Does the node's power usage vary, >> say by using the radio or something? >> >> MS > > Yes, the Duracells are fresh. The voltage is 1.6V for each battery. > The node periodically reads ADC value by a circuit with a strain gauge > and when the current value is higher or lower than a certain threshold > the node sends a broadcast alert to other nodes of the network and then > it returns to sleeping state. I can not understand why this difference > between types of batteries. Have you any idea? > > Greetings, > -- > Francesco Ficarola <francesco.ficarola_at_gmail_dot_com> > [GPG KeyID: 0xDBA99D92] > > > _______________________________________________ > Tinyos-help mailing list > [email protected] > https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help > -- ---------------------------------- Krišjānis Nesenbergs _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
