54 groups digital I / O input / output terminal (14 group can do PWM output)
16 sets of analog input terminal
Group 4 UART (hardware serial ports)
16 MHz crystal oscillator
With the bootloader， download the program directly via USB
Without having to go through other external writer
Supply part of the optional USB power， or as an external power
Using the AC-to-DC adapter and battery

LCD Keypad Shield Input / Output Expansion Board:
The Display features up to 2 lines of 16 characters on LCD， with contrast adjustment and a backlight lamp. 1 simulated export is used for 5 key input， 1 reset button is present， IO export can be fully utilized; wide range of digital ports: PIN4-DB4， PIN5-DB5， PIN6-DB6， PIN7-DB7， PIN8-RS， PIN9-E， PIN10- backlight control， Simulation of A0 key port.

Power Supply Automatically Switch:
The limited voltage is 6~12V， if the voltage is lower than 6V， the I/O port cannot supply 5V voltage
If the voltage is over 12V， the voltage stabilizer may take the overheat protection， and even damage the Arduino MEGA; So please use 6V~12V power source， 7.5V or 9V is recommend; Circuit improvements are based entirely on the Arduino official design