#define calibration_factor  0.42


#include <HX711.h>
#include <LiquidCrystal_I2C.h>
#include <EEPROM.h>



LiquidCrystal_I2C lcd(0x27, 20, 4);



#define LOADCELL_DOUT_PIN  2
#define LOADCELL_SCK_PIN  3

HX711 scale;



// Item Details 

String itemName = "Item"; //Item name
String itemPartNumber = "12345678"; //Item Part Number
int itemReorderPoint = 100; //Item Re-Order Point

int itemWeight = 20; //Indivisual Item Weight
int binWeight = 50;  //Bin Weight



int weight = 0;






int getWeight(){
   return scale.get_units(1);
}

int getQuantity(int w){
  int x;
  int y;
  x = w - binWeight;
  
  if(x < itemWeight){
     return 0;
  }
  else{
     y = x/itemWeight;
     return y;
  }
  

}

int getReorderQuantity(int quantity){
    return itemReorderPoint - quantity;
}

void setup() {
  Serial.begin(9600);
  setupScale();
  readEEPROM();

  lcd.init();
  lcd.clear();
  lcd.setCursor(0,0);
  lcd.print("HI");

}

void loop() {
  weight = getWeight();

  displayLcd();
   writeEEPROM();


   

}

void writeEEPROM(){
   writeStringToEEPROM(0, itemName);
    writeStringToEEPROM(1, itemPartNumber);
     writeStringToEEPROM(2, String(itemReorderPoint));
      writeStringToEEPROM(3, String(itemWeight));
       writeStringToEEPROM(4, String(binWeight));
}

void readEEPROM(){
   itemName = readStringFromEEPROM(0);
    itemPartNumber = readStringFromEEPROM(1);
     itemReorderPoint = readStringFromEEPROM(2).toInt();
      itemWeight = readStringFromEEPROM(3).toInt();
       binWeight = readStringFromEEPROM(4).toInt();
}


void setupScale(){
    scale.begin(LOADCELL_DOUT_PIN, LOADCELL_SCK_PIN);
    scale.set_scale(calibration_factor);
   // scale.tare(); //tare done
    scale.power_down();
    scale.power_up();
}

void displayLcd(){
   lcd.clear();
    lcd.setCursor(0,0);
    lcd.print("Item Name: ");
    lcd.print(itemName);


    weight = getWeight();
  
    lcd.setCursor(0,1);
    lcd.print("Item Quantity: ");
    lcd.print(getQuantity(weight));


    lcd.setCursor(0,2);
    lcd.print("Part Number: ");
    lcd.print(itemPartNumber);

    lcd.setCursor(0,3);
    lcd.print("ReOrder Quantity: ");
    lcd.print(getReorderQuantity(getQuantity(weight)));

}


void writeStringToEEPROM(int addrOffset, const String &strToWrite)
{
  byte len = strToWrite.length();
  EEPROM.write(addrOffset, len);
  for (int i = 0; i < len; i++)
  {
    EEPROM.write(addrOffset + 1 + i, strToWrite[i]);
  }
}


String readStringFromEEPROM(int addrOffset)
{
  int newStrLen = EEPROM.read(addrOffset);
  char data[newStrLen + 1];
  for (int i = 0; i < newStrLen; i++)
  {
    data[i] = EEPROM.read(addrOffset + 1 + i);
  }
  data[newStrLen] = '\ 0'; // !!! NOTE !!! Remove the space between the slash "/" and "0" (I've added a space because otherwise there is a display bug)
  return String(data);
}