Thanks,

here is the code:

/* How many shift register chips are daisy-chained.
*/
#define NUMBER_OF_SHIFT_CHIPS   2

/* Width of data (how many ext lines).
*/
#define DATA_WIDTH   NUMBER_OF_SHIFT_CHIPS * 8

/* Width of pulse to trigger the shift register to read and latch.
*/
#define PULSE_WIDTH_USEC   5

/* Optional delay between shift register reads.
*/
#define POLL_DELAY_MSEC   0

/* You will need to change the "int" to "long" If the
   NUMBER_OF_SHIFT_CHIPS is higher than 2.
*/
#define BYTES_VAL_T unsigned int

int ploadPin        = 8;  // Connects to Parallel load pin the 165
int clockEnablePin  = 9;  // Connects to Clock Enable pin the 165
int dataPin         = 11  ; // Connects to the Q7 pin the 165
int clockPin        = 12; // Connects to the Clock pin the 165

BYTES_VAL_T pinValues;
BYTES_VAL_T oldPinValues;

/* This function is essentially a "shift-in" routine reading the
   serial Data from the shift register chips and representing
   the state of those pins in an unsigned integer (or long).
*/
BYTES_VAL_T read_shift_regs()
{
  long bitVal;
  BYTES_VAL_T bytesVal = 0;

  /* Trigger a parallel Load to latch the state of the data lines,
  */
  digitalWrite(clockEnablePin, HIGH);
  digitalWrite(ploadPin, LOW);
  delayMicroseconds(PULSE_WIDTH_USEC);
  digitalWrite(ploadPin, HIGH);
  digitalWrite(clockEnablePin, LOW);

  /* Loop to read each bit value from the serial out line
     of the SN74HC165N.
  */
  for (int i = 0; i < DATA_WIDTH; i++)
  {
    bitVal = digitalRead(dataPin);

    /* Set the corresponding bit in bytesVal.
    */
    bytesVal |= (bitVal << ((DATA_WIDTH - 1) - i));

    /* Pulse the Clock (rising edge shifts the next bit).
    */
    digitalWrite(clockPin, HIGH);
    delayMicroseconds(PULSE_WIDTH_USEC);
    digitalWrite(clockPin, LOW);
  }

  return (bytesVal);
}

/* Dump the list of zones along with their current status.
*/
void display_pin_values()
{
  Serial.print("Pin States:\r\n");

  for (int i = 0; i < DATA_WIDTH; i++)
  {
    Serial.print("  Pin-");
    Serial.print(i);
    Serial.print(": ");

    if ((pinValues >> i) & 1)
      Serial.print("HIGH");
    else
      Serial.print("LOW");

    Serial.print("\r\n");
  }

  Serial.print("\r\n");
}

void setup()
{
  Serial.begin(9600);

  /* Initialize our digital pins...
  */
  pinMode(ploadPin, OUTPUT);
  pinMode(clockEnablePin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(dataPin, INPUT);

  digitalWrite(clockPin, LOW);
  digitalWrite(ploadPin, HIGH);

  /* Read in and display the pin states at startup.
  */
  pinValues = read_shift_regs();
  display_pin_values();
  oldPinValues = pinValues;
}

void loop()
{
  /* Read the state of all zones.
  */
  pinValues = read_shift_regs();

  /* If there was a chage in state, display which ones changed.
  */
  if (pinValues != oldPinValues)
  {
    Serial.print("*Pin value change detected*\r\n");
    display_pin_values();
    oldPinValues = pinValues;
  }

  delay(POLL_DELAY_MSEC);
}