#include <LiquidCrystal_I2C.h>
#define trig 8
#define echo 7
#define led_rot 12
#define led_gelb 11
#define led_gruen 10

LiquidCrystal_I2C lcd_1(0x27,20,4);

float abstand = 0.0;

void setup() {
  Serial.begin(115200);
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(led_rot, OUTPUT);
  pinMode(led_gelb, OUTPUT);
  pinMode(led_gruen, OUTPUT);
  lcd_1.init();
  lcd_1.backlight();
}

float readdistanceCM() {
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);

  abstand = pulseIn(echo, HIGH) / 58.0;
  return abstand;
}

void loop() {
  float distance = readdistanceCM();
  lcd_1.setCursor(7,0);

  delay(1000);

  // LEDs steuern
  if (distance < 30) {
    // Weniger als 30 cm
    setLEDs(HIGH, LOW, LOW);
    lcd_1.print(distance);
    delay(1000);
  } else if (distance < 60) {
    // Zwischen 30 cm und 60 cm
    setLEDs(LOW, HIGH, LOW);
    lcd_1.print(distance);
  } else {
    // Mehr als 60 cm
    setLEDs(LOW, LOW, HIGH);
    lcd_1.print(distance);
  }

  delay(2000);
}

// Funktion, um die LEDs zu setzen
void setLEDs(bool stateRot, bool stateGelb, bool stateGruen) {
  digitalWrite(led_rot, stateRot);
  digitalWrite(led_gelb, stateGelb);
  digitalWrite(led_gruen, stateGruen);
}