const int ledPin = PB6;
const int PWM = 8;
const int maxDutyCycle = 255;

const unsigned long fadeDuration = 3000;  

unsigned long previousTime = 0;
int currentDutyCycle = 0;
bool increasing = true;

void setup() {
  Serial.begin(115200);
  pinMode(ledPin, PWM);
  
  Serial.println("Плавное изменение яркости с точным таймингом");
  Serial.println("Используется метод millis() для точного времени");
}

void loop() {
  unsigned long currentTime = millis();
  unsigned long elapsedTime = currentTime % (fadeDuration * 2); 
  
  if (elapsedTime < fadeDuration) {
    currentDutyCycle = map(elapsedTime, 0, fadeDuration, 0, maxDutyCycle);
  } else {
    currentDutyCycle = map(elapsedTime, fadeDuration, fadeDuration * 2, maxDutyCycle, 0);
  }
  
  analogWrite(ledPin, currentDutyCycle);

  if (currentTime - previousTime >= 100) {
    previousTime = currentTime;
    
    int percent = map(currentDutyCycle, 0, maxDutyCycle, 0, 100);
    Serial.print("Время: ");
    Serial.print(elapsedTime);
    Serial.print(" мс, Яркость: ");
    Serial.print(percent);
    Serial.println("%");
  }

  delay(1);
}