AVR-Chat

I did this a while back, in a Tiny-26 with the AVR also doing the PWM
constant current buck regulation.   However, if I was to do it again
today, I'd leave the current regulation to an external chip unless
forced to do it this way for cost.

I think that NIMH cells are probably the most complicated of the
common chemistries to work with, if you really follow all the rules.
They are just plain delicate.