#include <LiquidCrystal_I2C.h>

#define trig 8
#define echo 7
#define led_rot 12
#define led_gelb 11
#define led_gruen 10


LiquidCrystal_I2C lcd1(0x27,20,4);
float abstand = 0.0;

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

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

void setLEDs(bool rot, bool gelb, bool gruen){
  digitalWrite(led_rot, rot);
  digitalWrite(led_gelb, gelb);
  digitalWrite(led_gruen, gruen);
}

void setup() {

  Serial.begin(115200);
  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);
  pinMode(led_rot, OUTPUT);
  pinMode(led_gelb, OUTPUT);
  pinMode(led_gruen, OUTPUT);
  lcd1.init();
  lcd1.backlight();

}



void loop() {
  float distance = readdistanceCM();
  Serial.print("Abstand in CM: ");
  Serial.println(distance);
  lcd1.clear();
  lcd1.setCursor(0,1);
  lcd1.print("CM Abstand:");
  lcd1.print(distance);
  if(distance < 10){
    setLEDs(HIGH,LOW,LOW);
  }else if (distance < 30){
    setLEDs(LOW,HIGH,LOW);
  }else{
    setLEDs(LOW,LOW,HIGH);
  }
  delay(1000);
}