> Several replies have led me to this conclusion, but your idea of 1 bit
> battery status is intriguing. But doesn't the 630 have an on board
> comparator?

Yeah, it does.  Think of it as a 12F629 with a few more port pins brought
out.

> You might have already had it dedicated to somthing else,

That was looked at, but I don't remember exactly why we used the
transistor.  The comparator would have required 4 parts (3 resistors and a
diode) whereas our solution used only 3 parts (2 resistors and a
transistor).  I know board space was a very big issue, but more likely it
had to do with certain pins needed for other things.

> but it seems to me that the on board comparator and switched resistor
> reference network could have given better resolution.

No, it wouldn't have worked at all.  The onboard reference only divides
Vdd, so wouldn't provide an independent reference for measuring Vdd (the
battery voltage).


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