I am sorry but I do not follow, "The bypass Caps ??". What do you mean?
I tell you what is confusing me though. That is the connection to CPU P0.7 pin that says if a battery is present or Not. Why should CM15A want to know if a battery is present? Surely it is more important to know if the mains voltage is there or not. More importantly there is no circuit to tell the CPU if the mains voltage is present or not except for the zero-cross detector (might be used as proxy by the software I guess). That I find very strange
At first I though X10 was trying to power the CPU down when no mains was available, like put it to sleep or suspend, to preserve battery power. As it is a 1000Mah battery lasts only 2 days or so without any electricity. Then when I studied the CPU documentation I notice that in a low power state the CPU's clock circuitry is shut down. Knowing that may be happy..
because a suspended CPU could not keep the clock running. the latter being precisely what we want to do.
Therefore I theorise that nothing cleaver is going on. The mains fail, the battery feeds the regulator through a simple diode, the power to CPU continues, and the CPU does not even hit that the mains is gone. The what on earth does it need the battery present signal? if any one knows then please lets hear it.
Matthew