4Bit HD44780 LCD and PCF8574 Pinout
      +-\/-+
 A0  1|    |16  VCC
 A1  2|    |15  SCA	
 A2  3|    |14  SCL
 RS  4|    |13  N/C
 RW  5|    |12  PD7
  E  6|    |11  PD6
CTRL 7|    |10  PD5
GND  8|    |9   PD4
      +----+