// by groundfungus in https://forum.arduino.cc/t/a-multifunction-button/1131935/6
// DaveX modified to demonstrate using similar logic on change in an analog signal
// Simulation demo at https://wokwi.com/projects/365991099114946561
const byte potentiometerPin = A0;    // the pin that the potentiometer is attached to
const int Hysteresis = 2;

// switch wired to ground and input

// Variables will change:
int buttonPushCounter = 0;   // counter for the number of zeros detected presses

void setup()
{
  // initialize the button pin as a input, enable the internal pullup resistor:
  pinMode(potentiometerPin, INPUT);

  // initialize serial communication:
  Serial.begin(9600);
  Serial.println("Use analog potentiometer at 0 as switch to cycle through 4 color choices");
  Serial.println(" (using state-change detection on the analog signal)");
}

void loop()
{
  static int lastPotentiometerState = 0;     // previous state of the button
  static unsigned long timer = 0;
  unsigned long interval = 50;
  if (millis() - timer >= interval)
  {
    timer = millis();
    // read the potentiometer input pin:
    int potentiometerState = analogRead(potentiometerPin);

    // compare the buttonState to its previous state
    if (abs(potentiometerState - lastPotentiometerState) > Hysteresis)
    {
      // On potentiometer change:
      Serial.print("Pot:");
      Serial.print(potentiometerState);
      Serial.print(' ');

      if (potentiometerState == 0) // treat as button push
      {
        // if the current state is LOW then the button
        // went from off to on:
        buttonPushCounter++;  // add one to counter
        if (buttonPushCounter > 3) // if couter over 3 reset the counter to 0 all off
        {
          buttonPushCounter = 0;
        }

        Serial.print("Button Push Counter = ");
        Serial.println(buttonPushCounter);
        Serial.print("color = ");
        switch (buttonPushCounter)
        {
          case 0:
            Serial.println("Black");
            break;
          case 1:
            Serial.println("Red");
            break;
          case 2:
            Serial.println("Green");
            break;
          case 3:
            Serial.println("Blue");
            break;
        }
      }

    }
    // save the current state as the last state,
    //for next time through the loop
    lastPotentiometerState = potentiometerState;
  }
}