#define S0 2
#define S1 3

void setup() {
  pinMode(S0, OUTPUT);
  pinMode(S1, OUTPUT);
  Serial.begin(115200);
}

void loop() {
  // put your main code here, to run repeatedly:
  for (byte i = 0; i < 3; i++) {
    Serial.print("Direcciona pin C");
    Serial.println(i);
    PORTD = (PORTD & 0b11110011) | (i << 2);
    delay(1000);
  }


}