Embed version of Mega 2560 CH340G/ATmega2560 - compatible with Arduino Mega 2560 board. Built on the Atmel ATmega2560 microcontroller and USB-UART interface chip CH340G.
Board have compact size 38x55mm. It is good solution, to make your final project on solder proto-board.
Board for functionality similar to the Arduino Mega 2560. It is embed board, but the same stable, and uses the original chips ATmega2560 (16 MHz).
The board used the chip CH340G as converter UART-USB. When you work in the frequency 12Mhz, giving a stable result of data exchange (need install drivers to computer).
Mega PRO (Embed) 2560 CH340G / ATmega2560 - connects to the computer via microUSB cable (used for almost all Android smartphones).
You can supply power to board through the MicroUSB connector or to power pinheaders. The voltage regulator (LDO) can deal with incoming voltage from 6V to 9V (peack 18V) DC. Output current for 5V - about 800mA, for 3.3V - about 800mA (Please note that the higher the input voltage the lower the outgoing current). That will provide a reliable power most of your initial projects.