I´ve spent hours trying to get a "power down" below 70µA with the "Nano". (I put a switch on the CH340G (china replacement of the FT232 chip, or whatever it is called, so I can remove the supplies to that chip). All arduino pins drive to zero, to they are stable and won't backfeed the CH340G and I follow the examples regarding the powerdown pre-procedure, using "power.h". That's just the background. Here's the question:
I read that the normal bootloader won't make you approach the 1µA, which one would expect if it was a non-bootloader application. There is "optiboot" available which seem to do a better job regarding the power consumption. Have any of you have some experience of replacing the bootloader? Or is it a work around to keep it? I mean will the bootloader override or deny any register poking I try to make?