4x4x4 Light Cube kit uses 64 cuboid LED,and controlled by Arduino. Expansion board uses two 
      74HC595 shift register chips, using eight I/Os can light the 4x4x4 Light Cube,
      it’s hardware resources needed is less than other 4x4x4 light cubic expansion board(needs 20 I/Os to control).
      1.Circuit Description
      The display part of ICSTATION 4x4x4 Light Cube kit consists of 64 cuboid LED,uses two 74HC595shift 
      register chip to control LED anode, the 4 I/O ports of Arduino controls 4 common cathodes of LED.
      2.Electrical parameters
      Control module:arduino control board
      PCB size:61*74mm
      LED color:blue
      Attention:
      1.You can choose round head or other color’s LED(Our kit is 5mm blue cuboid LED ).
      2.This kit is 4x4x4 light cubic expansion board,without arduino control chip or control module.
      3.Provide with arduino library,but there has less display effects,if you need more effects,
      you need to compile by yourself.                                                          The 0~15 slot of Diagram  is used for inserting  LED anode; D16~D19 slot is used 
      for inserting the LED cathode.

Expansion board and Arduino control pins.
      74HC595 pin                 arduino
      SH                                  0
      ST                                  1
      OE                                  2
      DS                                  3
      D16                                 4
      D17                                 5
      D18                                 6
      D19                                 7