#include <LiquidCrystal_I2C.h>
#define pinBuzzer 5
#define pinEcho 6
#define pinTrig 7

LiquidCrystal_I2C lcd(0x27,16,2);

void setup() {
  Serial.begin(115200);
  pinMode(pinBuzzer, OUTPUT);
  pinMode(pinEcho, INPUT);
  pinMode(pinTrig, OUTPUT);
  lcd.begin(16,2);
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(2,0);
  lcd.print("Deteksi Benda");
}
int catat = 0;
void loop() {
  int jarak = ukur_jarak();
  //Serial.print(jarak);
  if (jarak<25) {
    tanda_bahaya();
    delay(100);
        
  } else if (jarak<50) {
    tanda_peringatan();
    delay(500);
    
  } else if (jarak<150) {
    tanda_peringatan_awal();
    delay(1000);
    
  } else {
    tanda_aman();
  }
  if (catat!=jarak) {
    lcd.setCursor(0,1);
    lcd.print("                ");
    lcd.setCursor(0,1);
    lcd.print(jarak);
    lcd.print(" cm");
    catat = jarak;
  }
}

float ukur_jarak() {
  digitalWrite(pinTrig, LOW);
  delayMicroseconds(2);
  digitalWrite(pinTrig, HIGH);
  delayMicroseconds(10);
  digitalWrite(pinEcho, LOW);
  int hasil = pulseIn(pinEcho, HIGH);
  return hasil * 0.03425 / 2;
}
void tanda_bahaya() {
  tone(pinBuzzer,500,100);
  tone(pinBuzzer,750,200);
  tone(pinBuzzer,600,100);
}
void tanda_peringatan() {
  tone(pinBuzzer,700,100);
  tone(pinBuzzer,1500,200);
  tone(pinBuzzer,900,100);
}
void tanda_peringatan_awal() {
  tone(pinBuzzer,1500,200);
}
void tanda_aman() {
  noTone(pinBuzzer);
}