#include <NewPing.h>

#define trigPin 2
#define echoPin 3
#define max_distance 120

int LEDgreen = 5;
int LEDyellow = 6;
int LEDred = 7;

long distance;

NewPing sonar(trigPin, echoPin, max_distance);

void setup()   {                
  //Serial.begin(9600);
  //Serial.println("Parkassistant");
  
  pinMode(LEDgreen, OUTPUT);
  pinMode(LEDyellow, OUTPUT);
  pinMode(LEDred, OUTPUT);
  digitalWrite(LEDgreen, LOW);
  digitalWrite(LEDyellow, LOW);
  digitalWrite(LEDred, LOW);
}

void loop() {

  delay(500);
  distance = sonar.ping_cm();
  //Serial.println(distance);
  
  switch (distance) {
    case 0:
    digitalWrite(LEDgreen, LOW);
    digitalWrite(LEDyellow, LOW);
    digitalWrite(LEDred, LOW);
       break;
    case 31 ... 60:
    digitalWrite(LEDgreen, LOW);
    digitalWrite(LEDyellow, HIGH);
    digitalWrite(LEDred, LOW);
      break;
    case 1 ... 30:
    digitalWrite(LEDgreen, LOW);
    digitalWrite(LEDyellow, LOW);
    digitalWrite(LEDred, HIGH);
       break;
    default:
    digitalWrite(LEDgreen, HIGH);
    digitalWrite(LEDyellow, LOW);
    digitalWrite(LEDred, LOW);
      break;
  }

}