void setup() {
  // put your setup code here, to run once:
  unsigned char x_var;
  for(x_var=0;x_var<9;x_var++){
    pinMode(x_var+2, OUTPUT);
  }
}

unsigned char datos_UN[] = {0x3E, 0x54};

void write_7S_port(unsigned char dato){
  unsigned char x_var;
  for(x_var=0;x_var<7;x_var++){
    if(((dato >> x_var) & 0x01) == 1){
      digitalWrite(x_var + 2, HIGH);
    }
    else{
      digitalWrite(x_var + 2, LOW);
    }
  }
}

void loop() {
  // put your main code here, to run repeatedly:
  //rutina de multiplexacion para dos displays de siete segmentos
  write_7S_port(datos_UN[0]);
  digitalWrite(10, HIGH);
  delay(8);
  digitalWrite(10, LOW);
  write_7S_port(datos_UN[1]);
  digitalWrite(9, HIGH);
  delay(8);
  digitalWrite(9, LOW);
}