#define ENCODER_CLK 4
#define ENCODER_DT  5
#define BTN_PIN 6

int counter = 0;
int lastClk = HIGH;
int oldBtnVal = 1;  // INPUT_PULLUP idles HIGH

void checkButton()  {
  int btnVal = digitalRead(BTN_PIN);
  if (btnVal != oldBtnVal)  {
    oldBtnVal = btnVal;
    if (btnVal == LOW) {
      Serial.println("Switch pressed");
    } else  {
      Serial.println("Switch released");
    }
    delay(20);
  }
}

void setup() {
  Serial.begin(115200);
  pinMode(ENCODER_CLK, INPUT);
  pinMode(ENCODER_DT, INPUT);
  pinMode(BTN_PIN, INPUT_PULLUP);
}

void loop() {
  checkButton();
  int newClk = digitalRead(ENCODER_CLK);
  if (newClk != lastClk) {
    // There was a change on the CLK pin
    lastClk = newClk;
    int dtValue = digitalRead(ENCODER_DT);
    if (newClk == LOW && dtValue == HIGH) {
      counter++;
      Serial.print("Rotated CW ⏩");
      Serial.print("\tCounter: ");
      Serial.println(counter);
    }
    if (newClk == LOW && dtValue == LOW) {
      counter--;
      Serial.print("Rotated CCW ⏪");
      Serial.print("\tCounter: ");
      Serial.println(counter);
    }
  }
}