int x = 9;
void setup() {
  pinMode(13, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(9, OUTPUT);
  //INPUT: to read the tension value on this pin
  //OUTPUT: to regulate the tension value on this pin: e.g. switch on / off
}
void loop()  {
  digitalWrite(x, HIGH);
  delay (1000);
  digitalWrite(x, LOW);
  delay (1000);
  x = x+1;
  if ( x==14){
    x=9;
  }
}