i2c  detect  status

   20  -> MCP23008        48  -> tmp102      50  -> 24c32       60    ->  MCP4725     68 -> RTC DS1307

   21 , 22 -> 23017 x2

  use 23017-21.py  set each bit to be High or Low

  our new output test program     23017-2port-s-v103.py   display all 32 GPIO status

1. JP23  GA0 ~ GA7   U13 Port A       JP24 AA0 ~ AA7     U13 Port B

2. JP25  BA0 ~ BA7   U14 Port A        JP26 GB0 ~ BG7     U14 Port B

3 R61,R62,R63  ( for U13 Address select A0,A1,A2 )

4. R64,R65,R66 ( for  U14 Address select  A0,A1,A2)

5. U13 (21)  23017 -1  Port A,B           

6. U14 (22)   23017-2 Port A,B

7. pin out 2X10 , 

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

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

A0, A1, A2 address 

 *  right side GND low - 0      * left side Vcc High - 1

 000     -     20              001     -     21              010     -     22         011     -     23     

 100     -     24               101    -      25             110    -      26         111    -      27                  

Support our Pi_Scratch software   

  U1 to U2 i2c 23017  address 21,22

 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

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

  bit22b01010101 -->  address 22 port B from bit 8 to 1

                      output  --> 01010101  

  bit21a01010101 -->  address 21 port A from bit 8 to 1

                      output  --> 01010101  

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

  bit21boff  --> address 21 Port B all OFF/clear

  bit22aoff  --> address 22 Port A all OFF/clear