#define LED_PIN 15
#define BUTTON_PIN 12
#define SLIDE_PIN 34
#define ENCODER_CLK 5
#define ENCODER_DT  4
void LED_On(uint8_t brightness)
{
  Serial.println(brightness);

  pinMode(LED_PIN, OUTPUT);
  analogWrite(LED_PIN, 255 - brightness);
}
void LED_Off()
{
  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, HIGH);
}

bool button_up = true;
bool led_stat = false;
uint8_t brightness_set = 127;
uint8_t brightness_last = 0;


void readEncoder() {

  int dtValue = digitalRead(ENCODER_DT);
  if (dtValue == HIGH) {
    if (!led_stat)
      led_stat = true;
    if (brightness_set >= 255 - 8)
      brightness_set = 255;
    if (brightness_set < 255 - 8)
      brightness_set += 8;
  }
  if (dtValue == LOW) {
    if (brightness_set > 8)
      brightness_set -= 8;
    if (brightness_set <= 8)
    {
      brightness_set = 0;
      LED_Off();
      led_stat =  false;
    }
  }
  LED_On(brightness_set);
}


void setup() {
  Serial.begin(115200);
  LED_Off();
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(SLIDE_PIN, INPUT);
  pinMode(ENCODER_CLK, INPUT);
  pinMode(ENCODER_DT, INPUT);
  pinMode(LED_PIN, OUTPUT);

  attachInterrupt(digitalPinToInterrupt(ENCODER_CLK), readEncoder, FALLING);
}

void loop() {

  if (digitalRead(BUTTON_PIN) == LOW)
  {
    if (button_up)
    {
      button_up = false;
      led_stat = !led_stat;
    }
  }
  else
  {
    button_up = true;
  }
  if (led_stat)
  {
    if (brightness_last != brightness_set)
    {
      LED_On(brightness_set);
      brightness_last = brightness_set;
    }
  }
  else
    LED_Off();
  delay(10); // this speeds up the simulation
}