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 23017 Address select A0,A1,A2

   can rearrange 23017 location by your order

5. U2 ,U3 ,U4, U5 ,U6 ,U7,U8 ,U9  23017 Port A,B

6. each GPIO pin out 2X10 ,

    Bank B(1-10) GPIO (0,1,2,3,4,5,6,7,GND, INTB)

    Bank A(1-10) GPIO (0,1,2,3,4,5,6,7,GND, INTA)

   use i2cdetect -y 1   you can found 8 devices in system

   (20,21,22,23,24,25,26,27)

new output test program    23017-8port-s-v103.py  demo