//https://docs.wokwi.com/parts/wokwi-ky-040 참고

#define L_LED 13
#define ENCODER_A 2
#define ENCODER_B 3
#define SW 4

int lastStateA;
int lastStateSW;
int cnt = 0;
volatile int flag = LOW;
volatile int dir = LOW; //LOW == 시계방향, HIGH == 반시계방향

void setup() {
  pinMode(L_LED, OUTPUT);
  pinMode(ENCODER_A, INPUT);
  pinMode(ENCODER_B, INPUT);
  pinMode(SW, INPUT_PULLUP); //저항을 달거나 INPUT_PULLUP을 사용한다
  attachInterrupt(digitalPinToInterrupt(ENCODER_A), cntEncoder, CHANGE);
  lastStateA = digitalRead(ENCODER_A);
  lastStateSW = digitalRead(SW);
  Serial.begin(9600);
}

void cntEncoder()
{
  int StateA = digitalRead(ENCODER_A);
  int StateB = digitalRead(ENCODER_B);
  
  if (StateA == LOW && StateB == HIGH) {
    cnt++;
    //Serial.println("Rotated clockwise ⏩");
    //Serial.println(cnt);
    dir = LOW;
  }
  if (StateA == LOW && StateB == LOW) {
    cnt--;
    //Serial.println("Rotated counterclockwise ⏪");
    //Serial.println(cnt);
    dir = HIGH;
  }
  flag = HIGH;
  //lastStateA = StateA;
}

void loop() {
  //----------------------------------
  /*
  int StateA = digitalRead(ENCODER_A);

  if (StateA != lastStateA) { //엔코더A의 상태가 변하면
    int StateB = digitalRead(ENCODER_B);
    if (StateA == LOW && StateB == HIGH) {
      cnt++;
      Serial.println("Rotated clockwise ⏩");
      Serial.println(cnt);
    }
    if (StateA == LOW && StateB == LOW) {
      cnt--;
      Serial.println("Rotated counterclockwise ⏪");
      Serial.println(cnt);
    }
    lastStateA = StateA;
  }
  */
  //----------------------------------
  if(flag)
  {
    if(dir)
    {
      //반시계방향
      Serial.println("Rotated counterclockwise ⏪");
      Serial.println(cnt);
    }
    else
    {
      //시계방향
      Serial.println("Rotated clockwise ⏩");
      Serial.println(cnt);
    }
    flag = LOW;
  }

  //----------------------------------
  int sw_state = digitalRead(SW);
  if(lastStateSW != sw_state)
  {
    if(sw_state == LOW) //스위치 누르면, https://docs.wokwi.com/parts/wokwi-ky-040 참고
    {
      cnt = 0;
      Serial.println("cnt Reset " + cnt);
    }
    lastStateSW = sw_state;
  }
}