This MEGA2560 PRO Embedhas been developed for applications where an Arduino MEGA 2560 is just too bulky. It comes with the same powerful features and connections, but with a footprint of just 38 x 54 mm, which is only 38% of an Arduino MEGA 2560 Rev 3.
Another great advantage, besides the small size, is the much more capable voltage regulation on board. The MEGA2560 PRO Embed development board can deliver up to 800mA for 3.3V, compared to only 150mA for the Arduino MEGA 2560. This is plenty of current to power 3.3V devices like sensors, displays etc.
The ATmega2560 microcontroller has 54 digital input/output pins (of which 15 can be used as PWM outputs), 16 analog inputs, and 4 UARTs (hardware serial ports). It is supported by a USB-TTL bridge CH340, voltage regulators for 3.3V and 5V, LEDs for serial connection (RX/TX), Power and D13, ICSP programming header, USB Port and reset button.
MEGA2560 PRO Embed can be powered by USB (micro-USB port), a stabilized 5V power supply, or any unregulated voltage between 6V and 15V (18V absolute max. peak).
This MEGA2560 PRO Embedcontroller is 100% compatible to Arduino and the Arduino IDE after installing the Arduino bootloader (not factory installed). This can be done easily with another Arduino UNO, for example. You can find an easy tutorial here.
Operating Voltage: 5V
Input Voltage: 6-12V (recommended 7-9V) or 5V
Digital I/O Pins: 54 (of which 15 provide PWM output)
Analog Input Pins: 16
DC Current per I/O Pin: 20 mA
DC Current for 3.3V Pin: 800 mA *)
DC Current for 5V Pin: 800 mA *)
Flash Memory: 256 KB of which 8 KB used by bootloader
SRAM: 8 KB
EEPROM: 4 KB
Clock Speed: 16 MHz
Length: 54 mm
Width: 38 mm
Weight: 9 g (without headers)
*) Please do your math, and calculate the power dissipation of the voltage regulators, if you want to connect any periphery to the development board which draws current from the 5V or 3.3V rail. The power dissipation per voltage regulator must not exceed about 1W to not overheat them.
The MEGA 2560 is the better choice for more complex projects. With lots of digital and analog I/O pins, and a larger memory for your sketch, it is the recommended board for 3D printers and robotics projects. This gives your projects plenty of room and opportunities.