1. Provide 2x 20x2 40 pin same as Pi, one use 40pin GPIO cable connect to Pi

       one 20x2 40pin  for GPIO pin extra access.

   2. Provide extra i2c pin and spi pin for easy connect device

   3. Provide 128 GPIO status blue LED ,

4. Provide each 23s17 Address select A0,A1,A2

   can rearrange 23s17 location by your order

5.  U2 ,U3 ,U4, U5 ,U6 ,U7,U8 ,U9  23s17 Port A,B

6. Each GPIO pin out 2X10 ,