const byte potentioPin = A0;

const byte roodPin = 8;
const byte oranjePin = 12;
const byte groenPin = 4;

int input;
int percentage;

void setup() {
  // put your setup code here, to run once:
pinMode(potentioPin, INPUT);

pinMode(roodPin, OUTPUT);
pinMode(oranjePin, OUTPUT);
pinMode(groenPin, OUTPUT);

Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:

  input = analogRead(potentioPin);
  Serial.print(input);
  Serial.print("  -->  ");

  percentage = map(input, 0, 1023, 0, 100);
  Serial.print(percentage);
  Serial.println("%");

  if(percentage < 50)
  {
    digitalWrite(roodPin, HIGH);
    digitalWrite(oranjePin, LOW);
    digitalWrite(groenPin, LOW);
  }
  else if((percentage >= 50) && (percentage < 70))
  {
    digitalWrite(roodPin, LOW);
    digitalWrite(oranjePin, HIGH);
    digitalWrite(groenPin, LOW);
  }
  else
  {
    digitalWrite(roodPin, LOW);
    digitalWrite(oranjePin, LOW);
    digitalWrite(groenPin, HIGH);
  }
}