Power design of Mega 2560 R3 board:
1.For Arduino Mega power supply system has two options，
USB direct power supply or an external power supply.
2.Select the power supply will automatically switch.
3.Optional external power supply AC-to-DC adapter
or battery， this limits the control board voltage range 6V ~ 12V，
but if the voltage supplied is less than 6V， I / O ports may not
provide the 5V voltage， so there will be no stable; if the supplied
voltage is greater than 12V， the regulator will have the device
may overheat for protection， are more likely to damage the for Arduino
MEGA. Therefore， the operation of the proposed power supply
6.5 ~ 12V， 7.5V or recommended power supply is 9V.

Large screen: 12864LCD
1.Integration for SD card in the back， after slicing the
   file into the for SD card， you can select the
   corresponding files on the LCD.
2.The board has encoder， can be achieved
   parameter adjustment， and the file selection print!
3.The ramps can be Plug-and-Play， but it need
    to modify the firmware to support.

A4988 driver:
1.Low RDS (ON) outputs
2.Automatic current decay mode detection / selection
3.Mixed with slow current decay mode
4.Synchronous rectification for low power dissipation
5.Internal UVLO
6.Crossover current for protection
7.3.3 and 5V compatible logic supply
8.Thermal shutdown circuit
9.Ground short circuit for protection
10.Load short-circuit for protection
11.Five selectable stepper modes: full， 1/2， 1/4， 1/8 and 1/16

Package included:
1 x 12864 LCD board
1 x RAMPS 1.4 control board
1 x Mega 2560 R3 control board
5 x A4988 driver
1 x Adapter cable
2 x FC-10P flat cable