Smart Shopping Trolley Using RFID, ESP32 and IOT for Real-Time Bill Estimation

Abstract

Conventional shopping often requires customers to wait until checkout to learn the full cost of selected products. This paper presents a proposed smart shopping trolley that combines radio-frequency identification (RFID), an ESP32 microcontroller, an I²C liquid-crystal display (LCD), a servo actuator and Wi-Fi connectivity. Each participating product is associated with a registered RFID tag. When a tag is scanned, the controller looks up its product record, updates the basket total and presents the item name and price on the display. The ESP32 can also send basket information to an IoT web interface for remote viewing. The paper describes the architecture, hardware roles, software sequence, expected benefits, limitations and a practical evaluation plan. The design is a prototype proposal; no measured performance is claimed until the system is assembled and tested.

Introduction

The proposed system is an IoT-Based Smart Shopping Trolley using RFID and ESP32 designed to make shopping easier, faster, and more convenient. In traditional shopping, customers usually know their total bill only at the checkout counter, while manual barcode scanning can cause delays. The proposed smart trolley addresses these problems by automatically identifying products, calculating their prices, and displaying the running bill during shopping.

The system uses an RFID reader (RC522) to scan product tags and an ESP32 microcontroller to identify registered products from a stored product database. Once a product is detected, its name and price are retrieved, and the total bill is updated automatically. An LCD displays the product details and current bill, while Wi-Fi connectivity allows basket information to be transmitted to an IoT web server for remote monitoring.

The proposed system consists of five main modules: power supply, RFID reader, ESP32 controller, LCD and servo actuator, and IoT web server. A battery and buck converter provide regulated power to the components. The optional servo motor can operate a small gate or release mechanism.

The main objectives of the project include:

1. Automatic Product Identification: Identify registered products using RFID tags without requiring barcode scanning.

2. Real-Time Billing: Calculate and display the updated shopping total whenever products are added or removed.

3. User-Friendly Display: Show product names, prices, quantities, total cost, and error messages on an LCD.

4. IoT Connectivity: Send shopping basket information to a web server through ESP32 Wi-Fi connectivity.

5. Error Detection: Identify unregistered tags and prevent incorrect billing.

6. Efficient Shopping: Reduce manual checkout effort and help customers monitor their spending while shopping.

The operating process begins when the ESP32 initializes the RFID reader, LCD, servo, and Wi-Fi connection. When a customer scans a product, the RFID reader sends its unique identification number to the ESP32. The controller checks the product database and retrieves the corresponding details. If the product is registered, its price is added to the total bill and displayed on the LCD. The updated basket information can also be transmitted to the web server. If an unknown tag is detected, an error message is displayed without changing the bill.

The system also includes duplicate-scan handling, error management, and network-failure protection to improve reliability. It maintains the local shopping information even when Wi-Fi connectivity is unavailable.

Conclusion

This paper presents a proposed smart shopping trolley based on RFID, an ESP32 controller, an LCD, an optional servo and Wi-Fi communication. The reader identifies a tagged product, the controller retrieves the associated record, calculates an estimated basket total and presents the result locally. A web server can provide remote viewing of the basket summary. The architecture brings together product identification, embedded processing and IoT communication in a modular educational prototype. The usefulness of the design depends on reliable tag reads, correct product records, duplicate-scan control, stable power and appropriate error handling. The prototype should be evaluated using repeatable tests for identification, billing, display response and network recovery. Actual measurements must be reported before making claims about accuracy, time savings or commercial readiness.

References

[1] K. Finkenzeller, RFID Handbook: Fundamentals and Applications in Contactless Smart Cards, Radio Frequency Identification and Near-Field Communication, 3rd ed. Wiley, 2010. [2] Espressif Systems, “ESP32 Series Datasheet.” Available from the official Espressif documentation website. Consult the version corresponding to the development board used. [3] NXP Semiconductors, “MFRC522 Standard Performance MIFARE and NTAG Frontend,” product data sheet. Consult the manufacturer documentation for electrical and interface limits. [4] Arduino, “Arduino IDE Documentation.” Official documentation for developing and uploading embedded applications. [5] IEEE, “IEEE Editorial Style Manual for Authors,” guidance for technical-paper structure, references and figure captions. [6] M. R. Rieback, B. Crispo, and A. S. Tanenbaum, “The Evolution of RFID Security,” IEEE Pervasive Computing, vol. 5, no. 1, pp. 62–69, 2006. [7] A. Juels, “RFID Security and Privacy: A Research Survey,” IEEE Journal on Selected Areas in Communications, vol. 24, no. 2, pp. 381–394, Feb. 2006. [8] Espressif Systems, “ESP-IDF Programming Guide,” official documentation covering Wi-Fi configuration and application development.

Copyright

Copyright © 2026 Chaithra A C, Ramyashree V, Rishitha D, Ruchitha CU, Dr. Hadimani Shivakumar. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.