The power demands on the Arduino are the ATmega328P microcontroller, the ATmega16U2 microcontroller controlling the USB-to-serial interface, the 3.3V and 5V voltage regulators, and the three LEDs: power-on, transmit (TX), and receive (RX). There are several power-down options, but they only apply to the ATmega328P microcontroller.
The ATmega328P microcontroller has several functions that require power, including the three timers: Timer0, Timer1, and Timer2, and the three communication systems: Serial Peripheral Interface (SPI), Inter-Integrated Circuit (I2C), and serial communication (USART). The analog-to digital-converter ...
