Unfortunately there's no easy answer to the correct solution. One method is to setup interrupt service routines and put the mcu to sleep the rest of the time. There are a couple libraries that provide convenient interfaces to AVR's sleep lib e.g http://playground.arduino.cc/Code/Enerlib
The basic idea is that it is possible to put the chip into lower-power mode... but you need a way to wake it up after that. That could be an interrupt, watchdog timer... etc
Another thing to note is that for most applications the mcu's power consumption will be negligible with respect to the peripherals', so the average person shouldn't care much.
The basic idea is that it is possible to put the chip into lower-power mode... but you need a way to wake it up after that. That could be an interrupt, watchdog timer... etc
Another thing to note is that for most applications the mcu's power consumption will be negligible with respect to the peripherals', so the average person shouldn't care much.