#include <LiquidCrystal_I2C.h>

#define trigPin 8 // set pin Trig pada pin 8 Arduino
#define echoPin 7 // set pin Echo pada pin 7 Arduino
#define ledR 12 // set pin Led Merah pada pin 12 Arduino
#define ledY 11 // set pin Led Kuning pada pin 11 Arduino
#define ledG 10  // set pin Led Hijau pada pin 10 Arduino
#define Buzzer 9 // set pin positif Buzzer pada pin 9 Arduino

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);
 delay(500);
}

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

void setup() {
// deklarasi mode pin yang digunakan
 pinMode(trigPin, OUTPUT);
 pinMode(echoPin, INPUT);
 pinMode(ledR, OUTPUT);
 pinMode(ledY, OUTPUT);
 pinMode(ledG, OUTPUT);
 pinMode(Buzzer, OUTPUT);

// memulai lcd dengan fungsi bawaan library I2C
lcd.init();
lcd.backlight(); // setting lampu lcd agar menyala

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 Aman");
     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);}