int tiempo = 100;
int pin;
int pin10 = 10;
int pulsador1 = 12;
int pulsador2 = 13

void setup()
{
  for( pin = 1; pin <= 10; pin++)
  {
    pinMode(pin, OUTPUT);
  }
}

void loop()
{
 for( pin = 1; pin <= 10; pin++)
  {
    digitalWrite(pin, HIGH);
    delay(tiempo);
    digitalWrite(pin, LOW);
  }

  for( pin = 10; pin >= 1; pin--)
  {
    digitalWrite(pin, HIGH);
    delay(tiempo);
    digitalWrite(pin, LOW);
  }
}