#include <HX711_ADC.h>
#include <Wire.h>
#include "Arduino.h"
#include <LiquidCrystal_I2C.h>
#include <SoftwareSerial.h>

const byte rxPin = 9;
const byte txPin = 8;
int taree = 7;
SoftwareSerial MyBlue(rxPin, txPin); //RX TX
HX711_ADC LoadCell(4, 5); // parameters: dt pin, sck pin<span data-mce-type="bookmark" style="display: inline-block; width: 0px; overflow: hidden; line-height: 0;" class="mce_SELRES_start"></span>
LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); // 0x27 is the i2c address of the LCM1602 IIC v1 module (might differ)


void setup() {
  LoadCell.begin(); // start connection to HX711
  LoadCell.start(2000); // load cells gets 2000ms of time to stabilize
  LoadCell.setCalFactor(1715); // calibration factor for load cell => strongly dependent on your individual setup//1715
  lcd.begin(16, 2); // begins connection to the LCD module
  lcd.backlight(); // turns on the backlight
  lcd.setCursor(1, 0); // set cursor to first row
  lcd.print("Kitchen Scale "); // print out to LCD
  lcd.setCursor(0, 1); // set cursor to first row
  lcd.print(" 1KG MAX LOAD "); // print out to LCD
  pinMode(rxPin, INPUT);
  pinMode(txPin, OUTPUT);
  MyBlue.begin(9600);
  Serial.begin(9600);
  delay(2000);
  lcd.clear();
}

//int greutate = 0;
String messageBuffer ="";
String message= "";
int sum = 999;
int cnt = 1;
int buzzer = 6;
int maxWeight;
//init local variables that are used in the code

void loop()//ifnite loop sine the messages are transmited constantly
  {
    LoadCell.update(); // retrieves data from the load cell
   float i = LoadCell.getData();// get output value
  while(MyBlue.available()> 0) //there the message sent via bluetooth is transformed in decimal in order to be compared with the actual value measured on the scale
  {
    char data = MyBlue.read();
if(sum=999){
  sum=0;
}

    if(data!= ';') // the messaged sent on bluethoot has to end with an ; in order to see where it is finished
    {
        messageBuffer += data;
        cnt = data;
        sum = sum*10 + (cnt - 48);//-'0'
        Serial.print("sum=");
    Serial.print(sum);// convert char into int decrementing them with ascii value for 0
    }
    else
    {
        message = messageBuffer;
        messageBuffer ="";                        //i implemented this part of code, that has to set the max value of the scale via bluetooth. and when the value on the scale is >=
                                                  //than the value set from bluetooth temrinal, on the lcd shall apear a message and a sound from the buzzer
                                                  // my implementation works only when i hard code the value of sum( the value from bluetooth ). and the message from the bluetooth has to end with ";"
                                                  //
         cnt = 0;
         maxWeight = atoi(message);

  }
}
if( (sum < (int)i+5)) //the scale shall display the message error in case the measured value is higher than the one set via bluethoot mesage
{
    Serial.print("sum=");
    Serial.print(sum);
    Serial.print("\n");
    Serial.print("i=");
    Serial.print((int)i);
    Serial.print("\n");
    Serial.print("12321312");
    Serial.print("\n");
    lcd.setCursor(0, 1);
    lcd.print("MAX");
    tone(buzzer, 450);
    delay(300);
    sum=999;
     }

  lcd.setCursor(1, 0); // set cursor to first row
  lcd.print("Digital Scale "); // print out to LCD
  LoadCell.update(); // retrieves data from the load cell
 if (i<0.5)//set margin of error
 {
  if(i>-0.5){
    i=0;
     // i = i * (-1); //set margin of error
    lcd.setCursor(0, 1);
    lcd.print("");
    lcd.setCursor(8, 1);
    lcd.print("");
   }
  else
  {
    i = i * (-1);   //display the actual value added to the tare one
    lcd.setCursor(0, 1);
    lcd.print("-");
    lcd.setCursor(8, 1);
    lcd.print("-");
  }
 }
 else
 {
   lcd.setCursor(0, 1); //display the values in gr and oz
   lcd.print(" ");
   lcd.setCursor(8, 1);
   lcd.print(" ");
 }

  lcd.setCursor(1, 1); // set cursor to secon row
  lcd.print(i, 1); // print out the retrieved value to the second row
  lcd.print("g ");
  float z = i/28.3495; // convert gr to oz
  lcd.setCursor(9, 1);
  lcd.print(z, 2);
  lcd.print("oz ");

  if (i>=5000)
  {
    i=0;
  lcd.setCursor(0, 0); // set cursor to secon row
  lcd.print("  Over Loaded   ");
  delay(200);
  }
  if (digitalRead (taree) == LOW) //set tare
  {
    lcd.setCursor(0, 1); // set cursor to secon row
    lcd.print("   Taring...    ");
    LoadCell.start(1000);
    lcd.setCursor(0, 1);
    lcd.print("                ");
  }
  }