/*

########################################################
||                                                    ||
||   Title: 165 Shift Register w/ Test DIP Switches   ||
||                                                    ||
||                     By: GC1CEO                     ||
||                                                    ||
||Each DIP switch is connected to a parallel input pin||
|| on the 74HC165 and the program keeps polling each  ||
|| pin to see if it is HIGH or LOW and displaying the ||
||  resulting serial outputted byte into the Serial   ||
||                      Monitor.                      ||
||                                                    ||
|| It happens frequently that the current byte isn't  ||
||     registered properly, and changing bits too     ||
||     quickly makes this even more of a problem.     ||
||                                                    ||
||                                                    ||
||                                                    ||
########################################################

*/

const int dataPin = 2;   /* Q7 */
const int clockPin = 3;  /* CP */
const int latchPin = 4;  /* PL */
 
const int numBits = 8;   /* Set to 8 * number of shift registers */
 
void setup() {
  Serial.begin(115200);
  pinMode(dataPin, INPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(latchPin, OUTPUT);
}
 
void loop() {
  // Step 1: Sample
  digitalWrite(latchPin, LOW);
  digitalWrite(latchPin, HIGH);
 
  // Step 2: Shift
  Serial.print("Bits: ");
  for (int i = 0; i < numBits; i++) {
    int bit = digitalRead(dataPin);
    if (bit == HIGH) {
      Serial.print("1");
    } else {
      Serial.print("0");
    }
    digitalWrite(clockPin, HIGH); // Shift out the next bit
    digitalWrite(clockPin, LOW);
  }
 
  Serial.println();
  delay(1000);
}