The Arduino Nano V3 Atmega328 can be powered via the Mini-B USB connection, 6-15V unregulated external power supply (pin 30), or 5V regulated external power supply (pin 27). The power source is automatically selected to the highest voltage source. Memory. The ATmega328 has 32 KB, (also with 2 KB used for the bootloader). I looked up in the datasheet but I couldn't find an answer as to what is the output voltage of each pin. I assume it is the Voltage on any Pin except RESET with respect to Ground on page 303 but I would like to know for sure for both practical and educational purposes. Datasheet , pin-map and other information Of Atmega 8 Today i decide to publish the datasheet and pin-map of Atmega 8. This is importing to know this information of Atmega 8 to programming for it.