#include <Wire.h>
#include <PCF8574.h>

PCF8574 expander1;
PCF8574 expander2;

// the setup routine runs once when you press reset:
void setup()
{
  // initialize the digital pin as an output.
 
  expander1.begin(0x38);
  expander2.begin(0x39);
 
  for (int x=0; x <= 7; x++)
    {
      int b = 30+x;
     
      expander1.pinMode(x, INPUT);
      expander1.digitalWrite(x, HIGH);
     
      expander2.pinMode(x, INPUT);
      expander2.digitalWrite(x, HIGH);
     
      pinMode(b, OUTPUT);
    }
}

// the loop routine runs over and over again forever:
void loop()
{
  for (int i=0; i <= 7; i++)
  {
      int P1 = expander1.digitalRead(i);
      int P2 = expander2.digitalRead(i);
      int a = 30+i;
     
      if (P1 == 0 || P2 == 0)
      {
        digitalWrite(a, HIGH);
      }
 
      if (P1 == 1 && P2 == 1)
      {
        digitalWrite(a, LOW);
      }
   }
 
}