// Library dan penamaan LCD
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 20, 4);

// Pengalamatan pin
int tombol_obat = 2;
int tombol_jumlahobat = 3;
int tombol_mulai = 4;
int tombol_cancel = 5;

int a = 0;
int b = 0;
int c = 0;
int d = 0;

// Pembuatan variabel
int hitungMundur = 0;

int jumlah = 0;
String nama_obat = "";
int data_obat = 0;
int jumlah_obat = 1;

void setup()
{
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
  lcd.clear();

  pinMode(tombol_obat, INPUT);
  pinMode(tombol_jumlahobat, INPUT);
  pinMode(tombol_mulai, INPUT);
  pinMode(tombol_cancel, INPUT);

  attachInterrupt(digitalPinToInterrupt(3), interrupt, RISING);
}

void interrupt()
{
  hitungMundur = 0;
}

void loop()
{
  if (digitalRead(tombol_obat) == HIGH && c == 0)
  {data_obat += 1;
    c = 1;}
  else if (digitalRead(tombol_obat) == LOW && c == 1)
  {c = 0;}
  if (data_obat == 0)
  {nama_obat = "Gol. Darah A ";}
  else if (data_obat == 1)
  {nama_obat = "Gol. Darah B ";}
  else if (data_obat == 2)
  {nama_obat = "Gol. Darah AB";}
  else if (data_obat >= 3)
  {data_obat = 0;}

  if (digitalRead(tombol_jumlahobat) == HIGH && d == 0)
  { jumlah_obat += 1;
    if(jumlah_obat > 5){
      jumlah_obat = 1;
    }
    d = 1;}
  else if (digitalRead(tombol_jumlahobat) == LOW && d == 1)
  {d = 0;}

  if (digitalRead(tombol_mulai) == HIGH && a == 0)
  {hitungMundur = 5;
    a = 1;}
  else if (digitalRead(tombol_mulai) == LOW && a == 1)
  {a = 0;}
  
  lcd.setCursor(0, 0);
  lcd.print("Obat : ");
  lcd.print(nama_obat);
  lcd.setCursor(0, 1);
  lcd.print("Jumlah : ");
  lcd.print(jumlah_obat);
  if(digitalRead(tombol_cancel)==HIGH)
  {hitungMundur = 0;}

  if(hitungMundur > 0)
  {delay(1000);
    hitungMundur -= 1;}
  lcd.setCursor(0, 2);
  lcd.print("Timer : ");
  lcd.print(hitungMundur);

}