SmartCash - Intelligent Cash Register System
A smart cash register with product scanning, real-time alerts, and business monitoring features.
Author: David Adrian-Mario
GitHub Project Link: https://github.com/UPB-PMRust-Students/acs-project-2026-mariodavid3
Description
SmartCash is an intelligent cash register system designed to modernize small retail operations by integrating product scanning, real-time alerts, and smart monitoring features.
The system runs on a microcontroller platform and connects to a barcode scanner, display interface, and alert modules. It allows fast product identification, automatic price calculation, and detection of unusual events such as suspicious transactions, missing products, or system errors.
The device features a display interface that provides clear and real-time information to the user, including product name, price, and total cost. Additionally, the system includes a buzzer and LED-based alert mechanism that notifies the operator in case of errors, invalid scans, or unusual activities.
To enhance functionality, SmartCash can optionally communicate with a computer, allowing storage of transaction logs and management of product databases. This makes the system scalable and adaptable for more advanced retail applications.
Overall, SmartCash improves efficiency, reduces human error, and provides a more reliable and user-friendly solution for handling transactions in small retail environments.
Motivation
I chose this project because I am familiar with how markets and small shops operate, and I noticed that many systems are outdated and rely heavily on manual work. This leads to mistakes, slow service, and lack of control.
The goal is to build a smarter cash register that improves efficiency, reduces errors, and provides real-time alerts. Additionally, this project allowed me to explore the practical side of embedded systems development by integrating both hardware and software components into a single functional system.
Working with peripherals such as barcode scanners, displays, and communication interfaces helped me better understand how real-world devices operate.
Another important motivation was the possibility to design a system that can be extended in the future. SmartCash can evolve into a more complex solution by adding features such as inventory management, cloud connectivity, or mobile integration.
Overall, this project combines a real-world problem with a technical challenge, making it both useful and educational.
Architecture
The system is composed of the following main components:
- Main Controller: handles product processing, scanning logic, and alerts.
- Scanning Module: reads barcode data and sends it to the controller.
- Display Module: shows product information and total price.
- Alert Module: uses a buzzer and LEDs for notifications.
- Power Module: provides power to the controller and connected peripherals.
All components communicate through the microcontroller, which acts as the central processing unit.
Project Log
Week 1 - 11 May
Defined the project idea and the overall system architecture. The main components were selected and the basic functionality of the intelligent cash register was planned.
Week 2 - 18 May
Started the hardware setup and tested the barcode scanner and display module. The connections between the controller, display, and external modules were planned and partially assembled.
Week 3 - 25 May
Implemented the scanning logic and alert system. The buzzer and LED feedback were added for invalid scans, system errors, and user notifications.
Hardware
The project uses the following hardware components:
- Microcontroller board
- Barcode scanner
- LCD / TFT display
- Passive buzzer
- LEDs
- Buttons
- Breadboard
- Jumper wires
- Battery / external power source
Schematics
The electrical schematic was created in EasyEDA and includes the main controller, display, scanner interface, buzzer, connectors, and power connections.
Bill of Materials
| Device | Usage | Price |
|---|---|---|
| Microcontroller | Main processing unit | ~50 RON |
| Barcode scanner | Product scanning | ~70 RON |
| LCD / TFT display | User interface | ~80 RON |
| Passive buzzer | Audio alerts | ~10 RON |
| LEDs | Visual alerts | ~10 RON |
| Buttons | User interaction | ~5 RON |
| Jumper wires | Connections between components | ~20 RON |
| Breadboard | Prototyping connections | ~10 RON |
| USB cable | Power and communication with PC | ~15 RON |
Software
The software is responsible for reading scanned product data, processing product information, updating the display, and triggering alerts when needed.
| Library / Module | Description | Usage |
|---|---|---|
| embedded-hal | Hardware abstraction layer | Communication with peripherals |
| Display driver | Display control | UI rendering |
| UART / Serial | Serial communication | Barcode scanner input |
| GPIO | Digital input/output control | Buttons and LEDs |
| PWM | Pulse-width modulation | Buzzer control |
| SPI | Serial Peripheral Interface | Communication with display |
| I2C | Inter-integrated circuit | Future extensions |