#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 20, 4);

#define b1 1  // BUTTON 1
#define b2 2  // BUTTON 2
#define b3 3  // BUTTON 3
#define b4 4  // BUTTON 4
#define ledPin 12   // LAMPU LED INDIKATOR

int menu = 0;
String pilih = "";

void setup() {
  Serial.begin(115200);
  lcd.init();
  lcd.backlight();
  pinMode(b1, INPUT_PULLUP);
  pinMode(b2, INPUT_PULLUP);
  pinMode(b3, INPUT_PULLUP);
  pinMode(b4, INPUT_PULLUP);
  pinMode(ledPin, OUTPUT);

  lcd.setCursor(0, 1);
  lcd.print("--  Syringe Pump  --");
  lcd.setCursor(6, 2);
  lcd.print("Kelas C");
  delay(1500);
}

void loop() {
  if (menu == 0) {
    lcd.setCursor(0, 0);
    lcd.print("35ml           70ml");
    lcd.setCursor(0, 1);
    lcd.print("   TENTUKAN DOSIS   ");
    lcd.setCursor(0, 2);
    lcd.print("                   ");
    lcd.setCursor(0, 3);
    lcd.print("150ml         300ml");
    
    if (digitalRead(b1) == LOW) { pilih = "35ml   "; menu = 1; delay(500); }
    if (digitalRead(b2) == LOW) { pilih = "70ml   "; menu = 1; delay(500); }
    if (digitalRead(b3) == LOW) { pilih = "150ml  "; menu = 1; delay(500); }
    if (digitalRead(b4) == LOW) { pilih = "300ml  "; menu = 1; delay(500); }
  }
  
  if (menu == 1) {
    lcd.clear();
    lcd.setCursor(0, 1);
    lcd.print("DOSIS TERPILIH:");
    lcd.setCursor(0, 2);
    lcd.print(pilih);
    digitalWrite(ledPin, LOW);
    delay(1000);
    digitalWrite(ledPin, HIGH);
    menu = 0;
  }
}