> -----Original Message----- > From: Jan Egil Vestbø [mailto:[email protected]] > Sent: Monday, February 25, 2013 16:25 > To: Michiel Konstapel > Subject: Re: [Tinyos-help] Battery lifetime experiences > > Hi > > Thank you very much for a good answer.
You're welcome :-) >> 25. feb. 2013 kl. 11:52 skrev Michiel Konstapel > <[email protected]>: > > > If always on, the radio will consume about 20 mA in receive mode. The > Sensirion sensor has a fairly high VCC requirement (2.4V) so you won't > be able to use the full capacity of your batteries. > I once saw the sensor returning very wrong values once, and assumed it > was because of battery issues. Is this what happens, or will it stop > responding? Anything can happen once you go outside of the specs, but "incorrect values at first, then nothing" sounds quite likely. > > Assuming you can get about 1500 mAh from your AA cells, they'll last > about 3 days. If you use low power listening at an appropriate > interval, you should be able to get that down to the 1-2 mA range, so > that's about 10 times better. > This would give me 30 days, which would be more than enough for now. Do > you have any suggestions as to what sleep intervals would be good to > use? That's very hard to say, because it depends on how much traffic there is (both your own data and the control packets of network protocols) and how much overhearing you expect. However, something around 50 ms is pretty close to optimal as long as you stay below 1 message per second received + transmitted per node. > > The GPS will be a big drain on your batteries. If size is not an > issue, you could just hook them up to a set of D cells instead - those > have about 7 times the capacity of an AA (Duracel Procell). > > > I will not be using the GPS, but it is attached to the sensorboard. Am > I right that it will not be powered and not use much power if it is > never powered? That depends on the sensor board, and it's best to measure it - just turn everything off and see what your current drain is like. Best of luck! I'll be out of town for a while, so I won't be able to respond anytime soon. Best, Michiel _______________________________________________ Tinyos-help mailing list [email protected] https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
