// Start By The Name Of Allah
// Digital Scale Machine with Price feature
// By: Imran Sharif
// Technical Minds
//========================================================================================
#include <LiquidCrystal_I2C.h> // LiquidCrystal_I2C library  
#include <HX711_ADC.h> 
#include <EEPROM.h>
#include <Wire.h>
HX711_ADC LoadCell(2, 3); // parameters: dt pin, sck pin
LiquidCrystal_I2C lcd(0x27, 20, 4); // Set the LCD address to 0x27 for a 20 chars and 4 line display
#include <Keypad.h>
const byte ROWS = 4; //four rows
const byte COLS = 3; //three columns
char keys[ROWS][COLS] = {
  {'1','2','3'},
  {'4','5','6'},
  {'7','8','9'},
  {'*','0','#'}
};
byte rowPins[ROWS] = {11, 10, 9, 8}; //connect to the row pinouts of the keypad
byte colPins[COLS] = {7, 6, 5}; //connect to the column pinouts of the keypad
Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );
int led = 13;
int a = 0;
long b = 0;
int c = 0;
int Num1,Num2,Number;
const int calVal_eepromAdress = 0;
void setup() {
  Serial.begin(9600); delay(10);
  Serial.println();
  Serial.println("Starting...");
  pinMode(led, OUTPUT);
  lcd.begin(20, 4); // begins connection to the LCD module
  lcd.backlight(); // turns on the backlight
  LoadCell.begin(); // start connection to HX711
  LoadCell.start(2000); // load cells gets 2000ms of time to stabilize
  if (LoadCell.getTareTimeoutFlag() || LoadCell.getSignalTimeoutFlag())
    {
    Serial.println("Timeout, check MCU>HX711 wiring and pin designations"); 
    lcd.setCursor(1, 1);
    lcd.print("Check Load Cell");
    }
    else
    {
        LoadCell.setCalFactor(1.0); // 0.42 user set calibration value (float), initial value 1.0 may be used for this sketch
        Serial.println("Startup is complete");
    }
}
void loop() {
 char key = keypad.getKey();
  if ((key)&&(c<4))
  { 
 if (key == '1') //If Button 1 is pressed
    { 
    if (Number==0)
        Number=1;
    else
      Number = (Number*10) + 1; //Pressed twice
    }
if (key == '2') //Button 2 is Pressed
    { 
     if (Number==0)
       Number=2;
    else
       Number = (Number*10) + 2; //Pressed twice
    }
 if (key == '3')
    { 
     if (Number==0)
        Number=3;
    else
        Number = (Number*10) + 3; //Pressed twice
    }    
if (key == '4') //If Button 4 is pressed
    { 
    if (Number==0)
        Number=4;
    else
      Number = (Number*10) + 4; //Pressed twice
    }
if (key == '5')
    { 
     if (Number==0)
      Number=5;
    else
      Number = (Number*10) + 5; //Pressed twice
    }
 if (key == '6')
    {
    if (Number==0)
       Number=6;
    else
      Number = (Number*10) + 6; //Pressed twice
    }     
 if (key == '7') //If Button 7 is pressed
    { 
    if (Number==0)
      Number=7;
    else
      Number = (Number*10) + 7; //Pressed twice
    } 
if (key == '8')
    { 
     if (Number==0)
       Number=8;
    else
       Number = (Number*10) + 8; //Pressed twice
    }   
if (key == '9')
    {
    if (Number==0)
      Number=9;
    else
      Number = (Number*10) + 9; //Pressed twice
    }
 if (key == '0')
    {
    if (Number==0)
    {
       Number=0;
       c = c - 1;
    }
    else
       Number = (Number*10) + 0; //Pressed twice
    } 
      c = c + 1;
}
    if (key=='*') //If cancel Button is pressed
    {
     Number=0;
     c = 0;
    lcd.setCursor(16, 1); // set cursor to first row
    lcd.print("0    ");
    }
  LoadCell.update(); // retrieves data from the load cell
  float i = LoadCell.getData(); // get output value
    Serial.print("Load_cell output val: ");
    Serial.println(i);
    lcd.setCursor(11, 1); // set cursor to first row
    lcd.print(Number);   // Price that we entered 
    delay(1);
    lcd.setCursor(3, 3); // set cursor to first row
    lcd.print("Price = ");
b = (i* Number/1000); 
if(b<0)
{
  b=0; 
}
  lcd.setCursor(11, 3); // set cursor to secon row
  lcd.print(b, 1);   // total price
  lcd.print("   ");
  lcd.setCursor(0, 0); // set cursor to first row
  lcd.print("Digital Scale 50 KG "); // print out to LCD
  lcd.setCursor(0, 1); // set cursor to first row
  lcd.print("Price/KG = ");
  lcd.setCursor(2, 2); // set cursor to second row
  lcd.print("Weight = ");
  float k = i/1000;
  lcd.setCursor(11, 2); // set cursor to secon row
  lcd.print(k, 2); // print out the retrieved value to the second row
  lcd.print(" KG ");
  if (k>=50)
  {
  digitalWrite(led, HIGH);
  lcd.setCursor(0, 2); // set cursor to second row
  lcd.print("     Over Loaded   "); 
  delay(100);
  digitalWrite(led, LOW);
  }
  else
  {
  digitalWrite(led, LOW);
  }
  if (key=='#')
  {
    digitalWrite(led, HIGH);
    lcd.setCursor(0, 2); // set cursor to second row
    lcd.print("   Taring...        ");
    LoadCell.start(1000);
  }
  // receive command from serial terminal
  if (Serial.available() > 0) {
    char inByte = Serial.read();
    if (inByte == 't') LoadCell.tareNoDelay(); //tare
    else if (inByte == 'c') calibrate(); //calibrate
    else if (inByte == 'e') changeSavedCalFactor(); //edit calibration value manually
  }

  // check if last tare operation is complete
  if (LoadCell.getTareStatus() == true) {
    Serial.println("Tare complete");
  }    
}
void calibrate() 
{
  Serial.println("***");
  Serial.println("Start calibration:");
  Serial.println("Place the load cell an a level stable surface.");
  Serial.println("Remove any load applied to the load cell.");
  Serial.println("Send 't' from serial monitor to set the tare offset.");

  boolean _resume = false;
  while (_resume == false) {
    LoadCell.update();
    if (Serial.available() > 0) {
      if (Serial.available() > 0) {
        char inByte = Serial.read();
        if (inByte == 't') LoadCell.tareNoDelay();
      }
    }
    if (LoadCell.getTareStatus() == true) {
      Serial.println("Tare complete");
      _resume = true;
    }
  }

  Serial.println("Now, place your known mass on the loadcell.");
  Serial.println("Then send the weight of this mass (i.e. 100.0) from serial monitor.");

  float known_mass = 0;
  _resume = false;
  while (_resume == false) {
    LoadCell.update();
    if (Serial.available() > 0) {
      known_mass = Serial.parseFloat();
      if (known_mass != 0) {
        Serial.print("Known mass is: ");
        Serial.println(known_mass);
        _resume = true;
      }
    }
  }

  LoadCell.refreshDataSet(); //refresh the dataset to be sure that the known mass is measured correct
  float newCalibrationValue = LoadCell.getNewCalibration(known_mass); //get the new calibration value

  Serial.print("New calibration value has been set to: ");
  Serial.print(newCalibrationValue);
  Serial.println(", use this as calibration value (calFactor) in your project sketch.");
  Serial.print("Save this value to EEPROM adress ");
  Serial.print(calVal_eepromAdress);
  Serial.println("? y/n");

  _resume = false;
  while (_resume == false) {
    if (Serial.available() > 0) {
      char inByte = Serial.read();
      if (inByte == 'y') {
#if defined(ESP8266)|| defined(ESP32)
        EEPROM.begin(512);
#endif
        EEPROM.put(calVal_eepromAdress, newCalibrationValue);
#if defined(ESP8266)|| defined(ESP32)
        EEPROM.commit();
#endif
        EEPROM.get(calVal_eepromAdress, newCalibrationValue);
        Serial.print("Value ");
        Serial.print(newCalibrationValue);
        Serial.print(" saved to EEPROM address: ");
        Serial.println(calVal_eepromAdress);
        _resume = true;

      }
      else if (inByte == 'n') {
        Serial.println("Value not saved to EEPROM");
        _resume = true;
      }
    }
  }

  Serial.println("End calibration");
  Serial.println("***");
  Serial.println("To re-calibrate, send 'r' from serial monitor.");
  Serial.println("For manual edit of the calibration value, send 'c' from serial monitor.");
  Serial.println("***");
}

void changeSavedCalFactor() {
  float oldCalibrationValue = LoadCell.getCalFactor();
  boolean _resume = false;
  Serial.println("***");
  Serial.print("Current value is: ");
  Serial.println(oldCalibrationValue);
  Serial.println("Now, send the new value from serial monitor, i.e. 696.0");
  float newCalibrationValue;
  while (_resume == false) {
    if (Serial.available() > 0) {
      newCalibrationValue = Serial.parseFloat();
      if (newCalibrationValue != 0) {
        Serial.print("New calibration value is: ");
        Serial.println(newCalibrationValue);
        LoadCell.setCalFactor(newCalibrationValue);
        _resume = true;
      }
    }
  }
  _resume = false;
  Serial.print("Save this value to EEPROM adress ");
  Serial.print(calVal_eepromAdress);
  Serial.println("? y/n");
  while (_resume == false) {
    if (Serial.available() > 0) {
      char inByte = Serial.read();
      if (inByte == 'y') {
#if defined(ESP8266)|| defined(ESP32)
        EEPROM.begin(512);
#endif
        EEPROM.put(calVal_eepromAdress, newCalibrationValue);
#if defined(ESP8266)|| defined(ESP32)
        EEPROM.commit();
#endif
        EEPROM.get(calVal_eepromAdress, newCalibrationValue);
        Serial.print("Value ");
        Serial.print(newCalibrationValue);
        Serial.print(" saved to EEPROM address: ");
        Serial.println(calVal_eepromAdress);
        _resume = true;
      }
      else if (inByte == 'n') {
        Serial.println("Value not saved to EEPROM");
        _resume = true;
      }
    }
  }
  Serial.println("End change calibration value");
  Serial.println("***");
}