1. JP4    U1 Port A       JP3     U1 Port B

2. JP7    U2 Port A        JP8    U2 Port B

3. JP2    U3 Port A       JP1     U3 Port B

4. JP5    U4 Port A        JP6    U4 Port

5. JP11  U5 Port A       JP12    U5 Port B

6. JP13   U6 Port A       JP14   U6 Port B

7. JP16   U7 Port A       JP15   U7 Port B

8. JP10   U8 Port A       JP9     U8 Port B

9. U1 (20)  23017 -1  Port A,B    U2 (21)   23017-2 Port A,B

10. U3 (22)  23017 -3  Port A,B    U4 (23)   23017-4 Port A,B

11. U5 (24)  23017 -1  Port A,B    U6 (25)   23017-2 Port A,B

12. U7 (26)  23017 -3  Port A,B    U8 (27)   23017-4 Port A,B

 13. J1 i2c signal input  (PIN 1-4) GND, 5V, SDA, SCL  

23017-8 - 128 GPIO board plug in Raspberry Pi Model A/B

23017-8 - 128 GPIO board plug in Raspberry Pi  Model B+/B2 /B3

  in i2cdetect  you can found 8 device in system

(20,21,22,23,24,25,26,27)

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

 Support our Pi_Scratch software   

  U1 to U4 i2c 23017  address 20,21,22,23

  U5 to U8 i2c 23017  address 24,25,26,27

 Command "i2"+ "address(20-27)" + "a" +"bit(1 to 8)" 

for Port A

 Command "i2"+ "address(20-27)" + "b" +"bit(1 to 8)" 

for Port B

 Command "bit"+ "address(20-27)" + "a" +"bit(8 to 1)" 

for Port A

 Command "bit"+ "address(20-27)" + "b" +"bit(8 to 1)"

 for Port B

  i221a1 -->  i2c address 21 Port A bit 1 ON/OFF

  i220b7 -->  i2c address 20 Port B bit 7 ON/OFF

  i222b4 -->  i2c address 22 Port B bit 4 ON/OFF

  bit22b01010101 

-->  address 22 port B from bit 8 to 1

     output  --> 01010101  

  bit20a01010101 

-->  address 20 port A from bit 8 to 1

     output  --> 01010101  

  bit21aoff  --> address 21 Port A all OFF/clear

  bit23aclr  --> address 23 Port A all OFF/clear