int led1 = 2; 
int led2 = 3; 
int led3 = 4; 
int led4 = 5; 
int pot = A0; 
int potdeger; 
 
void setup() {
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT); 
  pinMode(led4, OUTPUT); 
  pinMode(pot, INPUT); 
}
 
void loop() {
  potdeger= analogRead(pot); 
 
  if (potdeger<250){ 
    digitalWrite(led1, LOW);
    digitalWrite(led2, LOW);
    digitalWrite(led3, LOW);
    digitalWrite(led4, LOW);
  }
  if (potdeger>250){ 
    digitalWrite(led1, HIGH);
    digitalWrite(led2, LOW);
    digitalWrite(led3, LOW);
    digitalWrite(led4, LOW);
  }
  if (potdeger>500){ 
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, LOW);
    digitalWrite(led4, LOW);
  }
  if (potdeger>750){ 
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, HIGH);
    digitalWrite(led4, LOW);
  }
    if (potdeger>1000){ 
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, HIGH);
    digitalWrite(led4, HIGH);
  }
}