Arduino_NANO_RFID_LCD_BUZZER_Smart_Shopping_Cart

#include <Arduino.h>
#include <SPI.h>
#include <MFRC522.h>
#include <LiquidCrystal_I2C.h>
#include <Wire.h>
#define SS_PIN 10
#define RST_PIN 9
#define buzzer 6
MFRC522 mfrc522(SS_PIN, RST_PIN);
LiquidCrystal_I2C lcd(0x27, 16, 2);

//char input[12];
String input;
int count = 0;

int a;
int p1 = 0, p2 = 0, p3 = 0, p4 = 0;
int c1 = 0, c2 = 0, c3 = 0, c4 = 0;

double total = 0;
int count_prod = 0;

void setup () {
  Serial.begin(9600);
  SPI.begin();
  mfrc522.PCD_Init();
  pinMode(A3, INPUT_PULLUP);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(buzzer, OUTPUT);
  lcd.init();
  lcd.init();
  lcd.backlight();
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(" AUTOMATIC BILL");
  delay (2000);
  lcd.setCursor(0, 1);
  lcd.print(" SHOPPING CART ");
  delay (2000);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("WELCOME TO");
  delay (2000);
  lcd.setCursor(3, 1);
  lcd.print("SUPER MARKET");
  delay (2000);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Plz Add iTem");
}



void loop() {
  readRFID();
  int a = digitalRead(A3);

  if (input == "29 36 CF B8" && (a == 1))
  {

    lcd.setCursor(0, 0);
    lcd.print("Butter Added       ");
    lcd.setCursor(0, 1);
    lcd.print("Price :- 10.00      ");
    p1++;
    digitalWrite(4, HIGH);
    digitalWrite(5, HIGH);
    delay(2000);
    total = total + 10.00;
    count_prod++;
    digitalWrite(4, LOW);
    digitalWrite(5, LOW);
    showTotal();
    input = "";
  }
  else if (input == "29 36 CF B8" && (a == 0))
  {
    if (p1 > 0)
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Butter Removed!!!        ");
      digitalWrite(4, HIGH);
      digitalWrite(5, HIGH);
      delay(2000);
      p1--;
      total = total - 10.00;
      count_prod--;
      lcd.clear();
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      showTotal();
      input = "";
    }
    else
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Not in cart!!!        ");
      digitalWrite(4, HIGH);
      digitalWrite(5, HIGH);
      delay(2000);
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      showTotal();
      input = "";
    }
  }


  if (input == "C6 91 09 2B" && (a == 1))
  {
    lcd.setCursor(0, 0);
    lcd.print("Milk Added       ");
    lcd.setCursor(0, 1);
    lcd.print("Price :- 20.00      ");
    p2++;
    digitalWrite(4, HIGH);
    digitalWrite(5, HIGH);
    delay(2000);
    total = total + 20.00;
    count_prod++;
    digitalWrite(4, LOW);
    digitalWrite(5, LOW);
    showTotal();
    input = "";
  }

  else if (input == "C6 91 09 2B" && (a == 0))
  {
    if (p2 > 0)
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Milk Removed!!!        ");
      digitalWrite(4, HIGH);
      digitalWrite(5, HIGH);
      delay(2000);
      p2--;
      total = total - 20.00;
      count_prod--;
      lcd.clear();
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      showTotal();
      input = "";
    }
    else
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Not in cart!!!        ");
      digitalWrite(4, HIGH);
      digitalWrite(5, HIGH);
      delay(2000);
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      showTotal();
      input = "";
    }
  }


  if (input == "03007C2DA0F2" && (a == 1))
  {
    lcd.setCursor(0, 0);
    lcd.print("Tea Added       ");
    lcd.setCursor(0, 1);
    lcd.print("Price :- 25.00      ");
    p3++;
    digitalWrite(4, HIGH);
    digitalWrite(5, HIGH);
    delay(2000);
    total = total + 25.00;
    count_prod++;
    digitalWrite(4, LOW);
    digitalWrite(5, LOW);
    showTotal();
    input = "";
  }

  else if (input == "03007C2DA0F2" && (a == 0))
  {
    if (p3 > 0)
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Tea Removed!!!        ");
      digitalWrite(4, HIGH);
      digitalWrite(5, HIGH);
      delay(2000);
      p3--;
      total = total - 25.00;
      count_prod--;
      lcd.clear();
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      showTotal();
      input = "";
    }
    else
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Not in cart!!!        ");
      digitalWrite(4, HIGH);
      digitalWrite(5, HIGH);
      delay(2000);
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      lcd.clear();
      input = "";
    }
  }
}

void readRFID() {
  // Look for new cards
  if ( ! mfrc522.PICC_IsNewCardPresent())
  {
    return;
  }

  // Select one of the cards
  if ( ! mfrc522.PICC_ReadCardSerial())
  {
    return;
  }

  //Show UID on serial monitor
  Serial.println ("");
  Serial.println("UID tag :");
  String content = "";
  byte letter;
  for (byte i = 0; i < mfrc522.uid.size; i++)
  {
    content.concat(String(mfrc522.uid.uidByte[i] < 0x10 ? " 0" : " "));
    content.concat(String(mfrc522.uid.uidByte[i], HEX));
    content.toUpperCase();
  }
  input = content.substring(1);
  digitalWrite(buzzer,1);
  delay(500);
  digitalWrite(buzzer,0);
  Serial.println(input);
  lcd.setCursor(0, 1);
  lcd.print(input);
}


void showTotal() {
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print("Total Price :-");
  lcd.setCursor(0, 1);
  lcd.print(total);
}