The library <avr/power.h> makes it easy to shut down all unneeded hardware of an ATmega controller.
The documentation of this library shows all available instructions and also on which controllers they are working. As I didn’t find this very readable I copied the table and deleted everything that doesn’t apply to the ATmega328P. Continue reading
An arduino board like the Uno can be a programmer for a standalone ATmega chip. For the ATmega328P that is used in the Uno there is a tutorial on the arduino homepage. This lets you burn the bootloader into the chip without the need for other hardware. This post shows how to use the same configuration for reading and writing the fuses on the chip. Continue reading