/*
  74HC165 Shift register input example
  (C) 2025, Kshyhoo
*/
const int dataPin = 2;   // Q7
const int clockPin = 3;  // CP
const int latchPin = 4;  // PL

void setup() {
  Serial.begin(9600);
  pinMode(dataPin, INPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(latchPin, OUTPUT);
}

void loop() {
  Serial.print("Q before CLK: ");
  for (int i = 0; i < 8; i++) {
    Serial.print(digitalRead(dataPin)); Serial.print(" ");
  }
  Serial.println();

  digitalWrite(latchPin, LOW);
  delayMicroseconds(5);
  digitalWrite(latchPin, HIGH);
  delayMicroseconds(5);

  Serial.print("Q after CLK: ");
  for (int i = 0; i < 8; i++) {
    Serial.print(digitalRead(dataPin)); Serial.print(" ");

      digitalWrite(clockPin, HIGH); 
    delayMicroseconds(5);
    digitalWrite(clockPin, LOW);
    delayMicroseconds(5);
  }
  Serial.println();

  Serial.print("CLK: ");
  Serial.print(digitalRead(clockPin));
  Serial.print(" LATCH: ");
  Serial.print(digitalRead(latchPin));
  Serial.println();

  delay(1000);
}