IOT Integrated Smart Cart: A Cloud-Centric Prototype for Automated Retail Monitoring

The rapid digitization of retail environments has intensified the need for efficient, scalable, and cost-effective checkout systems. Traditional billing counters depend heavily on manual scanning and cashier intervention, leading to long queues, billing errors, and inefficient transaction handling. This paper presents a cloud-centric IoT Integrated Smart Cart prototype that eliminates local display hardware and leverages Firebase Realtime Database for centralized monitoring and transaction logging. The proposed system integrates an ESP32 Dev Module, a USB barcode/QR scanner operating in UART mode, and a 10kg load cell with HX711 amplifier. Scanned product data is transmitted to Firebase using the Firebase Arduino library over Wi-Fi, typically through a mobile hotspot connection. Instead of performing bill calculations locally, the system logs scanned items and weight validation status in the cloud. Any mismatch between expected and actual cart weight is recorded as an alert in Firebase. The architecture reduces hardware complexity, enables real-time data synchronization (