The Mega2560 is based on the ATmega2560 chip and has 54 digital input / output pins (15 of which can be used for PWM), 16 analog input pins, 4 UARTs (hardware serial ports), a 16 MHz crystal oscillator, a USB connection , a power jack, an ICSP header, and a reset button.
The board contains everything needed to support the ATmega328 microcontroller. The Mega is compatible with most shields that are designed for the Arduino uno.
 
PROPERTIES
Power
5 V
Input voltage 
7 V - 12 V
Flash memory 
256 KB
Digital I/O 
54
PWM 
15
Stroom per I/O 
20 mA
Microcontroller 
ATmega2560
Clock speed 
16 MHz
EEPROM 
4 KB
SRAM 
8 KB
Analog I / O 
16