int led = 11;
int brillo0 = 64;
int brillo1 = 125;
int brillo2 = 190;
int brillo3 = 255;
void setup() {
  // put your setup code here, to run once:
pinMode(led, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
analogWrite(led, brillo0);
delay(350);

analogWrite(led, brillo1);
delay(350);

analogWrite(led, brillo2);
delay(350);

analogWrite(led, brillo3);
delay(350);
}