Power supply

The kit is powered from USB which leaves two options to power it: Either connect the kit to a PC through an USB cable, or to a 5V USB power supply (AC/DC adapter).

The 5V is regulated to 3.3V with a LDO regulator, which provides power to the entire board. The Atmel ATmega1284P is powered by 3.3V, but if 1.8V operation is desired some modifications to the board is needed. This includes replacing the regulator with one that delivers 1.8V output and rerouting the power to the device (see schematic for explanation). As some of the other ICs on the MEGA-1284P Xplained require 3.3V to operate correctly, these devices have to be removed.