led_count_up_down.ino

int ledPin = 13;
boolean btn_up,btn_down;

void setup() {
  // put your setup code here, to run once:
  pinMode(2, INPUT_PULLUP);
  pinMode(3, INPUT_PULLUP);

  for (int pin=6; pin<=13;pin++) {
    pinMode(pin, OUTPUT);
  }
  
  digitalWrite(ledPin,HIGH);
  
}

void loop() {
  // put your main code here, to run repeatedly:
  btn_up = digitalRead(2);
  btn_down = digitalRead(3);

  if (btn_up == LOW) {
     digitalWrite(ledPin,LOW);
     delay(250);
     ledPin++;
     if (ledPin > 13) ledPin=6;
     digitalWrite(ledPin,HIGH);
  }
  
  if (btn_down == LOW) {
     digitalWrite(ledPin,LOW);
     delay(250);
     ledPin--;
     if (ledPin < 6) ledPin=13;
     digitalWrite(ledPin,HIGH);
  }
}