Created December 30, 2024

Automated Billing System

Smart cart with RFID, ESP32, and Wi-Fi for real-time tracking, adding/removing items, and updating cart totals via web interface.

Things used in this project

Hardware components

Espressif ESP32 Development Board - Developer Edition

Adafruit RGB Backlight LCD - 16x2

Buzzer

SparkFun Pushbutton switch 12mm

5 mm LED: Red

5 mm LED: Green

RFID Reader/Writer RC522 SPI S50 with RFID Card and Tag

Software apps and online services

Arduino IDE

Story

This project is about creating a smart shopping cart system using an ESP32 microcontroller, RFID technology, and a web server to manage product tracking and cart updates in real-time. The project allows users to add or remove products from their cart by scanning RFID tags that represent specific items, each with a predefined price and quantity. I decided to create this project to explore the integration of RFID, web servers, and IoT devices in an interactive way that enhances the shopping experience while providing useful data for cart management.

The system works by first powering on the ESP32, which connects to a Wi-Fi network and starts a web server. The cart initially has a product cost and quantity set to zero. When an RFID tag is scanned by the reader, it checks whether the tag is recognized. Depending on the push button status (HIGH or LOW), it either adds the item to the cart or removes it, updating both the LCD display and the live web page. The web page displays real-time information about the items in the cart, including their names, quantities, prices, and the total cost, refreshing every two seconds. Additionally, visual and audio indicators are used: a yellow LED lights up when an item is added, and a red LED lights up when an item is removed, accompanied by a buzzer sound. The ESP32 also generates a local IP address after connecting to Wi-Fi, which users can enter in a browser to access the live HTML page and monitor the cart’s updates.

This project demonstrates how hardware and software can be integrated to build a simple yet effective smart shopping system, making it easy to track and manage purchases in a dynamic, real-time environment.

On a practical level, this project could make shopping more efficient, particularly in environments like stores or vending machines, where customers could track their purchases in real time. It also helps in tracking inventory and managing product quantities, which could be a valuable feature for both businesses and consumers. The integration of LEDs and a buzzer adds an element of immediate feedback, improving usability by providing clear indicators when an item is added or removed. This system could ultimately streamline shopping experiences, reduce errors, and make the process more intuitive.

Working of the system -

This video showcases the working of the system.

Implementation and Results -

Circuit Diagram

Web Page

Code

Code

#include <SPI.h>
#include <MFRC522.h>
#include <WiFi.h>
#include <ESPAsyncWebServer.h>
#include <Wire.h>
#include <SPIFFS.h>
#include <LiquidCrystal_I2C.h>

constexpr uint8_t RST_PIN = 15;    
constexpr uint8_t SS_PIN = 4;    
#define YLED 33
#define RLED 27
#define BUZZER 2
#define BUTTON 5  

int lcdColumns = 16;
int lcdRows = 2;
LiquidCrystal_I2C lcd(0x27, lcdColumns, lcdRows);  

MFRC522 rfid(SS_PIN, RST_PIN); // Instance of the class
MFRC522::MIFARE_Key key;

AsyncWebServer server(80);

const char *ssid = "Replace with your SSID";
const char *password = "Replace with your Passoword";

String tag;
String page = "";

char input[12];
int count = 0;
 
int a;

int p1 = 0, p2 = 0, p3 = 0, p4 = 0, p5=0, p6=0;
int c1 = 0, c2 = 0, c3 = 0, c4 = 0, c5=0, c6=0;
double total = 0;
int count_prod = 0;

void setup() {
  pinMode(YLED, OUTPUT);
  pinMode(RLED, OUTPUT);
  pinMode(BUZZER, OUTPUT);
  pinMode(BUTTON, INPUT_PULLUP);

  lcd.init();
  lcd.backlight();
 
  Serial.begin(115200);
  SPI.begin(); // Init SPI bus
  rfid.PCD_Init(); // Init MFRC522

  WiFi.begin(ssid, password);
  Serial.println("Connecting to wifi");
  while (WiFi.status() != WL_CONNECTED)
  {
    delay(1000);
    Serial.println(".");
  }
  Serial.println("\nWifi Connected");
  Serial.println(WiFi.localIP());
  lcd.setCursor(0, 0);
  lcd.print("Wifi Connected");
  delay(2000);
  lcd.clear();
  lcd.setCursor(0, 0);
  lcd.print(WiFi.localIP());
  delay(2000);
  lcd.clear();

  Serial.println("Welcome to VON Mart");
  Serial.println("Happy Shopping");
  lcd.setCursor(0, 0);
  lcd.print("Welcome");
  delay(1000);
  lcd.setCursor(0, 1);
  lcd.print("Happy Shopping");
  delay(1000);
  lcd.clear();

  server.on("/", HTTP_GET, [](AsyncWebServerRequest *request) {
    page = "<html><head><title>ECart</title>";
    page += "<style type=\"text/css\">";
    page += "body { background-color: #f0f0f0; font-family: Arial, sans-serif; }";
    page += "h1 { color: #3498db; }";
    page += "table { width: 1200px; height: 450px; border-collapse: collapse; margin-top: 20px; background-color: #ffffff; box-shadow: 0 0 10px rgba(0, 0, 0, 0.1); }";
    page += "th { background-color: #3498db; color: white; padding: 15px; }";
    page += "td { border: 4px solid black; font-size: large; text-align: center; border-style: groove; border-color: rgb(255, 0, 0); padding: 10px; }";
    page += "input[type=\"button\"] { background-color: #3498db; color: white; width: 200px; height: 50px; font-size: large; border: none; cursor: pointer; }";
    page += "input[type=\"button\"]:hover { background-color: #2980b9; }";
    page += "</style></head>";
    page += "<body><center><h1>Welcome to VON Mart</h1><br><br>";
    page += "<table><tr><th>ITEMS</th><th>QUANTITY</th><th>COST</th></tr>";
    page += "<tr><td>NesCafe</td><td>" + String(p1) + "</td><td>" + String(c1) + "</td></tr>";
    page += "<tr><td>OREO</td><td>" + String(p2) + "</td><td>" + String(c2) + "</td></tr>";
    page += "<tr><td>Sugar</td><td>" + String(p3) + "</td><td>" + String(c3) + "</td></tr>";
    page += "<tr><td>Sprite</td><td>" + String(p4) + "</td><td>" + String(c4) + "</td></tr>";
    page += "<tr><td>Chips</td><td>" + String(p5) + "</td><td>" + String(c5) + "</td></tr>";
    page += "<tr><td>Colgate</td><td>" + String(p6) + "</td><td>" + String(c6) + "</td></tr>";
    page += "<tr><th>Grand Total</th><th>" + String(count_prod) + "</th><th>" + String(total) + "</th></tr>";
    page += "</table><br><input type=\"button\" name=\"Pay Now\" value=\"Pay Now\"></center></body></html>";
    page += "<meta http-equiv=\"refresh\" content=\"2\">";
    request->send(200, "text/html", page);
  });
  server.begin();
}

void loop() {
  count=0;
  if ( ! rfid.PICC_IsNewCardPresent())
    return;
  if (rfid.PICC_ReadCardSerial()) {
    for (byte i = 0; i < 5; i++) {
      tag += rfid.uid.uidByte[i];
    }
    Serial.println(tag);
    int a = digitalRead(5);
    if((tag=="67542372530")&&(a==HIGH)){
      Serial.println("Product name : NesCafe ") ;
      Serial.println("Product price : 35 Rs");
      lcd.setCursor(0, 0);
      lcd.print("NesCafe Added");
      lcd.setCursor(0, 1);
      lcd.print("Price : 35");
      p1++;
      total += 35 ;
      count_prod++;
      digitalWrite(33, HIGH);
      delay(1000);
      digitalWrite(33, LOW);
      tone(BUZZER, 1000);
      delay(500);
      noTone(BUZZER);
      digitalWrite(27, LOW);
      delay(1000);
      Serial.println("Nescafe added to the Cart");
      lcd.clear();
    }
    else if((tag=="67542372530")&&(a==LOW))
    {
    if (p1 > 0)
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("NesCafe Removed");
      p1--;
      total = total - 35;
      count_prod--;
      digitalWrite(33, LOW);
      tone(BUZZER, 1000);
      delay(500);
      noTone(BUZZER);
      digitalWrite(27, HIGH);
      delay(1000);
      digitalWrite(27, LOW);
      delay(1000);
      lcd.clear();}
      else
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Not in cart");
      delay(1000);
      lcd.clear();
    }
  }
    if((tag=="17074191220")&&(a==HIGH)){
      Serial.println("Product name : OREO ") ;
      Serial.println("Product price : 10 Rs");
      lcd.setCursor(0, 0);
      lcd.print("OREO Added");
      lcd.setCursor(0, 1);
      lcd.print("Price : 10");
      p2++;
      total += 10 ;
      count_prod++;
      digitalWrite(33, HIGH);
      delay(1000);
      digitalWrite(33, LOW);
      tone(BUZZER, 1000);
      delay(500);
      noTone(BUZZER);
      digitalWrite(27, LOW);
      delay(1000);
      Serial.println("OREO added to the Cart");
      lcd.clear();
    }
    else if ((tag=="17074191220")&&(a==LOW))
    {
    if (p2 > 0)
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("OREO Removed");
      digitalWrite(33, LOW);
      tone(BUZZER, 1000);
      delay(500);
      noTone(BUZZER);
      digitalWrite(27, HIGH);
      delay(1000);
      digitalWrite(27, LOW);
      delay(1000);
      p2--;
      total = total - 10;
      count_prod--;
      lcd.clear();}
      else
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Not in cart");
      delay(1000);
      lcd.clear();
    }
  }
    if((tag=="247821171010")&&(a==HIGH)){
      Serial.println("Product name : Sugar ") ;
      Serial.println("Product price : 80 Rs");
      lcd.setCursor(0, 0);
      lcd.print("Sugar Added");
      lcd.setCursor(0, 1);
      lcd.print("Price : 80");
      p3++;
      total += 80 ;
      count_prod++;
      digitalWrite(33, HIGH);
      delay(1000);
      digitalWrite(33, LOW);
      tone(BUZZER, 1000);
      delay(500);
      noTone(BUZZER);
      digitalWrite(27, LOW);
      delay(1000);
      Serial.println("Sugar added to the Cart");
      lcd.clear();
    }
    else if ((tag=="247821171010")&&(a==LOW))
    {
    if (p3 > 0)
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Sugar Removed");
      digitalWrite(33, LOW);
      tone(BUZZER, 1000);
      delay(500);
      noTone(BUZZER);
      digitalWrite(27, HIGH);
      delay(1000);
      digitalWrite(27, LOW);
      delay(1000);
      p3--;
      total = total - 80;
      count_prod--;
      lcd.clear();}
      else
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Not in cart");
      delay(1000);
      lcd.clear();
    }
  }
     if((tag=="1952511572530")&&(a==HIGH)){
      Serial.println("Product name : Sprite ") ;
      Serial.println("Product price : 40 Rs");
      lcd.setCursor(0, 0);
      lcd.print("Sprite Added");
      lcd.setCursor(0, 1);
      lcd.print("Price : 40");
      p4++;
      total += 40 ;
      count_prod++;
      digitalWrite(33, HIGH);
      delay(1000);
      digitalWrite(33, LOW);
      tone(BUZZER, 1000);
      delay(500);
      noTone(BUZZER);
      digitalWrite(27, LOW);
      delay(1000);
      Serial.println("Sprite added to the Cart");
      lcd.clear();
    }
    else if((tag=="1952511572530")&&(a==LOW))
    {
    if (p4 > 0)
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Sprite Removed");
      delay(1000);
      p4--;
      total = total - 40;
      count_prod--;
      digitalWrite(33, LOW);
      tone(BUZZER, 1000);
      delay(500);
      noTone(BUZZER);
      digitalWrite(27, HIGH);
      delay(1000);
      digitalWrite(27, LOW);
      delay(1000);
      lcd.clear();}
      else
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Not in cart");
      delay(1000);
      lcd.clear();
    }
  }
  if((tag=="184205161180")&&(a==HIGH)){
      Serial.println("Product name : Chips ") ;
      Serial.println("Product price : 20 Rs");
      lcd.setCursor(0, 0);
      lcd.print("Chips Added");
      lcd.setCursor(0, 1);
      lcd.print("Price : 20");
      p5++;
      total += 20 ;
      count_prod++;
      digitalWrite(33, HIGH);
      delay(1000);
      digitalWrite(33, LOW);
      tone(BUZZER, 1000);
      delay(500);
      noTone(BUZZER);
      digitalWrite(27, LOW);
      delay(1000);
      Serial.println("Chips added to the Cart");
      lcd.clear();
    }
    else if((tag=="184205161180")&&(a==LOW))
    {
    if (p5 > 0)
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Chips Removed");
      delay(1000);
      p5--;
      total = total - 20;
      count_prod--;
      digitalWrite(33, LOW);
      tone(BUZZER, 1000);
      delay(500);
      noTone(BUZZER);
      digitalWrite(27, HIGH);
      delay(1000);
      digitalWrite(27, LOW);
      delay(1000);
      lcd.clear();}
      else
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Not in cart");
      delay(1000);
      lcd.clear();
    }
  }
    if((tag=="9912522470")&&(a==HIGH)){
      Serial.println("Product name : Colgate ") ;
      Serial.println("Product price : 100 Rs");
      lcd.setCursor(0, 0);
      lcd.print("Colgate Added");
      lcd.setCursor(0, 1);
      lcd.print("Price : 100");
      p6++;
      total += 100 ;
      count_prod++;
      digitalWrite(33, HIGH);
      delay(1000);
      digitalWrite(33, LOW);
      tone(BUZZER, 1000);
      delay(500);
      noTone(BUZZER);
      digitalWrite(27, LOW);
      delay(1000);
      Serial.println("Colgate added to the Cart");
      lcd.clear();
    }
    else if((tag=="9912522470")&&(a==LOW))
    {
    if (p6 > 0)
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Colgate Removed");
      delay(1000);
      p5--;
      total = total - 100;
      count_prod--;
      digitalWrite(33, LOW);
      tone(BUZZER, 1000);
      delay(500);
      noTone(BUZZER);
      digitalWrite(27, HIGH);
      delay(1000);
      digitalWrite(27, LOW);
      delay(1000);
      lcd.clear();}
      else
    {
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Not in cart");
      delay(1000);
      lcd.clear();
    }
  }

    c1=p1*35.00;
    c2=p2*10.00;
    c3=p3*80.00;
    c4=p4*25.00;
    c5=p5*20.00;
    c6=p6*100.00;
   
    tag = "";
    rfid.PICC_HaltA();
    rfid.PCD_StopCrypto1();
   
  }
}

Credits

vrisha shah

1 project • 0 followers

Automated Billing System

Things used in this project

Hardware components

Software apps and online services

Story

Schematics

Circuit Diagram

Code

Code

Credits

vrisha shah

Comments

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Automated Billing System

Automated Billing System

Things used in this project

Hardware components

Software apps and online services

Story

Schematics

Circuit Diagram

Code

Code

Credits

vrisha shah

Comments