#include <LiquidCrystal_I2C.h>

#define trigpin 10
#define echopin 11
#define ledR 6
#define ledY 5
#define ledG 4
#define Buzzer 9

LiquidCrystal_I2C lcd  (0x27,16,2);

float mengukur_jarak() {
digitalWrite(trigpin, HIGH);
delayMicroseconds(10);
digitalWrite(trigpin, LOW);

long duration = pulseIn(echopin, HIGH);
float distance = duration/58;

return distance;
}

void kondisi_aman(){
digitalWrite(ledG, HIGH);
}

void kondisi_hati(){
digitalWrite(ledY, HIGH);
delay(500);
digitalWrite(ledY, LOW);
}

void kondisi_bahaya(){
digitalWrite(ledR, HIGH);
delay(500);
digitalWrite(ledR, LOW);
delay(200);
}

void setup() {
pinMode(trigpin, OUTPUT);
pinMode(echopin, INPUT);
pinMode(ledR, OUTPUT);
pinMode(ledY, OUTPUT);
pinMode(ledG, OUTPUT);
pinMode(Buzzer, OUTPUT);

lcd.init();
lcd.backlight();

digitalWrite(trigpin, LOW);
delayMicroseconds(2);
}

void loop() {
  lcd.clear();
  digitalWrite(ledR, LOW);
  digitalWrite(ledY, LOW);
  digitalWrite(ledG, LOW);
  digitalWrite(Buzzer, LOW);  

  float jarak_terukur = mengukur_jarak();
  if (jarak_terukur >= 100){
    lcd.setCursor(0,0);
    lcd.print("Jarak Aaman");
    kondisi_aman();
  }
  else if (jarak_terukur < 100 && jarak_terukur >=50){
    lcd.setCursor(0,0);
    lcd.print("Jarak: ");
    lcd.print(jarak_terukur);
    lcd.print(" cm");
    lcd.setCursor(0,1);
    lcd.print("Hati-Hati");
    kondisi_hati();
  }
  else{
 lcd.setCursor(0,0);
 lcd.print("Jarak: ");
 lcd.print(jarak_terukur);
 lcd.print(" cm");
 lcd.setCursor(0,1);
 lcd.print("BAHAYA");
 kondisi_bahaya();
}
delay (500);
mengukur_jarak();
}