//   Arduino Pro Micro   74HC165
int clock =        15;   // CLK
int clockInhibit =  4;   // CLK/INH
int load =         10;   // SH/LD#
int dataIn =       14;   // QH

// Define other variables of the code
byte switchStates1, switchStates2, switchStates3, switchStates4, switchStates5, switchStates6, switchStates7, switchStates8, switchStates9;

byte us = 50; // logic diagram timing (µs)

void setup() {
  // Setup Serial Monitor
  Serial.begin(9600);

  // Setup 74HC165 connections
  pinMode(load, OUTPUT);
  pinMode(clockInhibit, OUTPUT);
  pinMode(clock, OUTPUT);
  pinMode(dataIn, INPUT);
}

void loop() {

  // Write pulse to load pin
  digitalWrite(clock, HIGH);
  delayMicroseconds(us);
  digitalWrite(load, LOW);
  delayMicroseconds(us);
  digitalWrite(load, HIGH);
  delayMicroseconds(us);

  // Get data from 74HC165
  digitalWrite(clockInhibit, LOW);
  delayMicroseconds(us);
  switchStates1 = myShiftIn(dataIn, clock, MSBFIRST);
  switchStates2 = myShiftIn(dataIn, clock, MSBFIRST);
  switchStates3 = myShiftIn(dataIn, clock, MSBFIRST);
  switchStates4 = myShiftIn(dataIn, clock, MSBFIRST);
  switchStates5 = myShiftIn(dataIn, clock, MSBFIRST);
  switchStates6 = myShiftIn(dataIn, clock, MSBFIRST);
  switchStates7 = myShiftIn(dataIn, clock, MSBFIRST);
  switchStates8 = myShiftIn(dataIn, clock, MSBFIRST);
  switchStates9 = myShiftIn(dataIn, clock, MSBFIRST);
  digitalWrite(clockInhibit, HIGH);

  // Print to serial monitor
  Serial.print("Pin States -- 1 -- 1-8:\r\n");
  Serial.println(switchStates1, BIN);//[0], BIN);
  Serial.print("Pin States -- 2 -- 9-16:\r\n");
  Serial.println(switchStates2, BIN);//[1], BIN);
  Serial.print("Pin States -- 3 -- 17-24:\r\n");
  Serial.println(switchStates3, BIN);//[2], BIN);
  Serial.print("Pin States -- 4 -- 25-32:\r\n");
  Serial.println(switchStates4, BIN);//[3], BIN);
  Serial.print("Pin States -- 5 -- 33-40:\r\n");
  Serial.println(switchStates5, BIN);//[4], BIN);
  Serial.print("Pin States -- 6 -- 41-48:\r\n");
  Serial.println(switchStates6, BIN);//[5], BIN);
  Serial.print("Pin States -- 7 -- 49-56:\r\n");
  Serial.println(switchStates7, BIN);//[6], BIN);
  Serial.print("Pin States -- 8 -- 57-64:\r\n");
  Serial.println(switchStates8, BIN);//[7], BIN);
  Serial.print("Pin States -- 9 -- 65-72:\r\n");
  Serial.println(switchStates9, BIN);//[8], BIN);

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

  delay(500);
}

uint8_t myShiftIn(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder) {
  uint8_t value = 0;
  uint8_t i;

  for (i = 0; i < 8; ++i) {
    digitalWrite(clockPin, HIGH);
    delayMicroseconds(us);
    if (bitOrder == LSBFIRST)
      value |= digitalRead(dataPin) << i;
    else
      value |= digitalRead(dataPin) << (7 - i);
    digitalWrite(clockPin, LOW);
    delayMicroseconds(us);
  }
  return value;
}