#define buttonUp 2
#define buttonDown 3
#define LED 4
int counter;

void setup() {
  pinMode(buttonUp, INPUT);
  pinMode(buttonDown, INPUT);
  pinMode(LED, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  if (digitalRead(buttonUp) == LOW) {
    counter++;
    delay(300);
  }

  if (digitalRead(buttonDown) == LOW) {
    counter--;
    delay(300);
  }

  if (counter >= 10) {
    counter = 10;
  }
  else if (counter <= 0) {    
    counter = 0;
  }
  if (counter >=4 && counter <=7) {
  digitalWrite(LED,HIGH);
  }
  else{
  digitalWrite(LED,LOW);
  }
  Serial.println(counter);
}