Introduction

A Smart Shopping Trolley is an innovative solution for modern retail stores, designed to assist customers, track items, and automate billing. By integrating IoT, sensors, and automation, a smart trolley improves shopping efficiency and user convenience.

This project is useful for supermarkets, smart malls, and retail research projects.

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Objective of the Project

• To track products placed in the trolley using sensors
• To provide automatic billing and reduce checkout time
• To monitor the trolley’s movement and location
• To demonstrate smart retail technology

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Working Principle

1. The trolley is equipped with weight sensors or RFID sensors to detect products
2. Each product is tagged with RFID tags or barcodes
3. When a product is placed in the trolley, sensor data is sent to microcontroller
4. Microcontroller processes items and calculates total cost
5. Optional: IoT integration sends the shopping list and bill to a mobile app
6. Some designs also include trolley movement tracking and anti-theft mechanisms

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Components Required

• Arduino / ESP32
• RFID Reader Module (RC522)
• RFID Tags (for products)
• LCD / OLED Display (for showing total)
• Buzzer (for alerts)
• Wi-Fi Module (ESP8266 / ESP32 built-in) for IoT
• Power supply and trolley frame
• Jumper wires

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Block Diagram

RFID Tag on Product
        ↓
   RFID Reader on Trolley
        ↓
   Arduino / ESP32
        ↓
 LCD / OLED Display
        ↓
 Total Price & Notifications
        ↓
 Optional: Mobile App (IoT)

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Circuit Connections (Arduino + RFID)

RFID RC522

SDA → D10
SCK → D13
MOSI → D11
MISO → D12
IRQ → Not Used
GND → GND
3.3V → 3.3V
RST → D9

LCD 16×2

RS → D7
EN → D6
D4 → D5
D5 → D4
D6 → D3
D7 → D2
VSS → GND
VDD → 5V
V0 → Potentiometer middle pin

Buzzer

+ → D8
- → GND

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Arduino Code (Smart Shopping Trolley)

#include <SPI.h>
#include <MFRC522.h>
#include <LiquidCrystal.h>

#define RST_PIN 9
#define SS_PIN 10
MFRC522 mfrc522(SS_PIN, RST_PIN);

LiquidCrystal lcd(7,6,5,4,3,2);
int buzzer = 8;

struct Product {
  String uid;
  String name;
  int price;
};

// Example Product Database
Product products[] = {
  {"04 A1 B2 C3 D4", "Milk", 50},
  {"12 34 56 78 90", "Bread", 30},
  {"AB CD EF 12 34", "Eggs", 70}
};

void setup() {
  lcd.begin(16,2);
  Serial.begin(9600);
  SPI.begin();
  mfrc522.PCD_Init();
  pinMode(buzzer, OUTPUT);
  lcd.print("Smart Trolley");
  delay(2000);
  lcd.clear();
}

void loop() {
  if ( ! mfrc522.PICC_IsNewCardPresent()) return;
  if ( ! mfrc522.PICC_ReadCardSerial()) return;

  String uid = "";
  for (byte i = 0; i < mfrc522.uid.size; i++) {
    uid += String(mfrc522.uid.uidByte[i], HEX);
    if(i < mfrc522.uid.size-1) uid += " ";
  }
  
  Serial.println(uid);
  
  bool found = false;
  for(int i=0; i<3; i++){
    if(products[i].uid == uid){
      lcd.clear();
      lcd.print(products[i].name);
      lcd.setCursor(0,1);
      lcd.print("Price: Rs ");
      lcd.print(products[i].price);
      Serial.print("Product: ");
      Serial.println(products[i].name);
      Serial.print("Price: ");
      Serial.println(products[i].price);
      digitalWrite(buzzer, HIGH);
      delay(200);
      digitalWrite(buzzer, LOW);
      found = true;
      break;
    }
  }
  if(!found){
    lcd.clear();
    lcd.print("Product Not Found");
  }
  delay(1000);
}

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Code Explanation

• RFID reader reads UID of product tag
• Microcontroller checks UID against predefined product database
• If matched, product name and price are displayed on LCD
• Buzzer gives a notification for scanned item
• Optional IoT integration can send data to a mobile app for billing

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Advantages

• Automates product scanning and billing
• Reduces checkout time
• Enhances customer shopping experience
• Can be integrated with IoT for advanced features

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Applications

• Smart supermarkets and malls
• Retail automation
• Self-checkout systems
• Educational projects on IoT and automation

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Future Enhancements

• Integration with mobile app for automatic billing
• Weight sensors to detect product removal or addition
• QR code scanning for cheaper tags
• Anti-theft mechanism using IoT alerts

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Conclusion

The Smart Shopping Trolley is a mini + innovation project that demonstrates IoT, RFID technology, and smart retail automation. It helps streamline shopping, reduces manual effort, and showcases modern technology in retail systems.