// https://forum.arduino.cc/t/function-for-incrementing-an-integer-value/1045878

# define NPINS  4   // actual number realized in wiring

const int buttonPin[8] = {3, 4, 5, 6,}; // just four four now

int scene[8] = {0, 0, 0, 0, 0, 0, 0, 0};

bool dirt = false;   // just to keep printing to a minumum

int lastButtonState[8] = {HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH};
int buttonState[8] = {HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH, HIGH};

void sceneSelect(int potNum)
{
  buttonState[potNum] = digitalRead(buttonPin[potNum]);
  if (buttonState[potNum] != lastButtonState[potNum]) {
    if (buttonState[potNum] == LOW) {
      scene[potNum]++;
      if (scene[potNum] >= 5) scene[potNum] = 0;

      dirt = true;    // we need to print out all the scene values as there has been a change
    }

    lastButtonState[potNum] = buttonState[potNum];
  }
}

void setup()
{
  Serial.begin(9600);
  Serial.println("function for incrementing an integer value\n");

  for (unsigned char tt = 0; tt < NPINS; tt++)
    pinMode(buttonPin[tt], INPUT_PULLUP);
}

void loop()
{
  for (unsigned char tt = 0; tt < NPINS; tt++)
    sceneSelect(tt);

  if (dirt) {
    for (unsigned char tt = 0; tt < NPINS; tt++) {
      Serial.print(scene[NPINS - 1 - tt]);  // printing was backwards
      Serial.print(" ");
    }
    Serial.println();

    dirt = false;
  }
  
  delay(20);    // effective global debounce!
}