#include <HX711.h>
#include <TM1637Display.h>
#include <LiquidCrystal_I2C.h>
#include <Keypad.h>
#define CALIBRATION_FACTOR 352.83 //this number is taken from HX_kitchen_scale_cal
LiquidCrystal_I2C lcd(0x27, 2, 16);
byte pinDt = 4; // DOUT
byte pinSck = 3; // SCK
HX711 scale; 

/* Keypad setup */
const byte KEYPAD_ROWS = 4;
const byte KEYPAD_COLS = 4;
byte rowPins[KEYPAD_ROWS] = {12, 11, 10, 9}; // pin numbers of each input button
byte colPins[KEYPAD_COLS] = {8, 7, 6, 5}; // pin numbers of each input button
char keys[KEYPAD_ROWS][KEYPAD_COLS] = {
  {'1', '2', '3', 'A'},
  {'4', '5', '6', 'B'},
  {'7', '8', '9', 'C'},
  {'*', '0', '#', 'D'}
};

Keypad keypad = Keypad(makeKeymap(keys), rowPins, colPins, KEYPAD_ROWS, KEYPAD_COLS);
uint64_t value = 0;
char Tare = 'A'; // clear lcd, reset to 0
char Enter = 'B'; // enter
char Clear = 'C'; // clear keypad input
char Delete = 'D'; // delete last number inputted 

int count = 0;
unsigned long savedNumber=0;
TM1637Display display(A0, A1);

void setup()
{
  lcd.begin(16, 2);
  lcd.init();
  lcd.backlight();
  lcd.print("ENGINEERING");
  lcd.setCursor(0, 1);
  lcd.print("GOOD");
  delay(2000);
  lcd.clear();
  Serial.begin(57600);
  scale.begin(pinDt, pinSck);
  scale.set_scale(CALIBRATION_FACTOR); // this value is obtained by calibrating the scale with known weights;
  scale.tare();
  display.setBrightness(7);//for 4digit
}

void loop() 
{
  lcd.setCursor(0, 1);
  char key = keypad.getKey(); 
  lcd.print(key);
  //Serial.print(scale.get_units(2),0);
   
  if (key >= '0' && key <= '9')
  {
    lcd.setCursor (count,0);
    lcd.print (key);
    savedNumber = savedNumber * 10 + (key - '0'); // Convert the pressed key to a number
    Serial.print("Entered number: ");
    Serial.println(savedNumber);
    lcd.setCursor (0,0);
    count ++;
  }
  else if (key == Clear) 
  {
    lcd.clear();
    savedNumber = 0;
    count = 0;  
  }
  else if (key == Delete)  
  {
    int count1 = 0;
    count1=count--;
    lcd.setCursor (count1,0);
    lcd.clear();
    savedNumber = (savedNumber / 10);
    Serial.print("Deleted Last Digit. New Number: ");
    Serial.println(savedNumber);
    lcd.println (savedNumber);
    if(count1 <= 0){count = 0;}//to ensure the lcd cursor will not go negative
  }
  else if (key == Tare) 
  {
    lcd.clear();
    savedNumber = 0;
    count = 0;
    scale.tare(); 
    lcd.print ("Taring Complete");
    delay(1000);
    lcd.clear();
  }
  else if (key == Enter)  
  {
    Serial.println("Entering while loop...");
    Serial.print (key);
    while (true) 
    {
     // Your code inside the while loop goes here
     // This code will keep executing until the "C" button is pressed
     Serial.print(savedNumber);
     lcd.setCursor(0, 1);
     lcd.print(scale.get_units(2),0);
     lcd.print(" Gram");
     lcd.print("          ");
     // Check if the "C" button is pressed to exit the loop
     if (keypad.getKey() == 'C') 
      {
       Serial.println("Exiting while loop...");
       break;
      }
    }
  }
  display.showNumberDec(savedNumber-scale.get_units(1));
  //delay(2000);
 
}