Alan B. Pearce wrote:

>>I'm using the maxstream firmware with cyclic sleep, with nothing
>>more than their own firmware.
> 
> I think this is your trouble. I suspect the on-board firmware only goes
> into a standby mode, if it goes to sleep it probably requires something
> external to wake it up. It may not even be able to go to sleep on its
> own, it may need to be commanded to go to sleep.

It has a cyclic sleep mode. The mode it enters is similar to the one that's
called "pin doze" -- it has a higher consumption than "pin hibernate", but
it's still not more than approx. 40uA (@3V).

Anyway, it seems that at least one problem you're having is with the
discharge curve of the AA batteries. You can try to use a Lithium battery
and see where you're getting (check out the discharge curve and compare it
with alkaline; it's flatter). Also, check whether your sleep cycle is what
you'd expect; both in terms of duration and in terms of consumption. 

Consumption is a bit tricky to measure, because a resistor that gives you
enough voltage drop during the sleep phase probably has too much drop when
the module is awake. A simple solution would be to have a make-before-break
switchover between two resistors and do it by hand. (With the 4 minutes
between wakeups you said you have, you can easily manually switch to the
higher resistor once it is in sleep mode, measure the current, and then
switch back. Important is that the switchover happens without interruption
of the supply.)

Gerhard

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