#include <Wire.h>                //NANO   
#include <LiquidCrystal_I2C.h>   //LIBRARY LCD
#include "HX711.h"               //LIBRARY LOADCELL

const int ldrPin = A0;    //CODINGAN LDR

const int irSensorPin = 2;  //INFRARED


LiquidCrystal_I2C lcd(0x27, 20, 4);    //LCD
HX711 scale;                    //LOADCELL
float calibration_factor = -400; //Nilai awal perkiraan
float units;                      //LOADCELL
float ounces;                     //LOADCELL

void setup() {

 pinMode(irSensorPin, INPUT);  //INFRARED

 Serial.begin(9600);           //LCD
 Serial.println("HX711 Kalibrasi");      //LOADCELL
 Serial.println("Jangan ada benda apapun diatas load cell"); //ini penting

 Serial.println("Kemudian letakan benda"); //misalnya batu baterai yang sudah diketahui beratnya
 
 Serial.println("Tekan + atau a untuk meningkatkan faktor kalibrasi");
 Serial.println("Tekan - atau z untuk mengurangi faktor kalibrasi");
scale.begin(3, 2);
 scale.set_scale();
 scale.tare();

 long zero_factor = scale.read_average(); 
 Serial.print("Zero factor: ");
 Serial.println(zero_factor);
lcd.init();
scale.begin(A0, A1);
}

void loop() {

int irStatus = digitalRead(irSensorPin);     //INFRARED

  // Tampilkan status sensor IR di Serial Monitor
  Serial.print("Status IR: ");
  Serial.println(irStatus);

  // Tampilkan status sensor IR di LCD 20x4
  
  lcd.setCursor(0, 2);
  lcd.print("IR: ");
  
  if (irStatus == HIGH) {
    lcd.print("Takada darah");
  } else {
    lcd.print("Darah Naik");
  }

  delay(1000);  // Tunda 1 detik sebelum membaca ulang //INFRARED

  int ldrValue = analogRead(ldrPin);  //CODINGAN LDR
  Serial.print("Nilai LDR: ");       //CODINGAN LDR
  Serial.println(ldrValue);           //CODINGAN LDR

  // Tampilkan nilai LDR di LCD 20x4
                    
  lcd.setCursor(0, 1);                      //CODINGAN LDR
  lcd.print("Nilai LDR: ");                //CODINGAN LDR
  lcd.print(ldrValue);                     //CODINGAN LDR

  delay(1000);  // Tunda 1 detik sebelum membaca ulang  LDR

scale.set_scale(calibration_factor);       //LOADCELL

 Serial.print("Pembacaan : ");           //LOADCELL
 units = scale.get_units(), 10;          //LOADCELL
 if (units < 0)
 {
 units = 0.00;
 }
 ounces = units * 0.035274;
 Serial.print(units);
 Serial.print(" grams"); 
 Serial.print(" calibration_factor: ");
 Serial.print(calibration_factor);
 Serial.println();

 if(Serial.available())
 {
 char temp = Serial.read();
 if(temp == '+' || temp == 'a')
 calibration_factor += 1;
 else if(temp == '-' || temp == 'z')
 calibration_factor -= 1;

int weight = scale.get_units(10);
lcd.setCursor(0,0);
lcd.print("Weight: " + String(weight) + " G");
if (weight < 1.5) {
  lcd.setCursor(0,0);
  lcd.print("Cairan infus Habis");
  delay(1000);
}

lcd.setCursor(0, 0);                          //LCD
lcd.print("Berat: "+ String(scale.get_units(10), 1) + " G");  //LCD TO LOADCELL
delay(1000);
}
}