A Low-Cost, Low-Latency IoT-RFID Attendance System with Real-Time Cloud Synchronization: Design and Field Evaluation

This study showcases an affordable IoT-based RFID attendance solution featuring real-time cloud synchronization through an ESP8266 NodeMCU, MFRC522 RFID reader, and a serverless Google Apps Script–Google Sheets setup. The suggested system attains an average end-to-end latency of 0.92 seconds, concurrently eliminating ongoing communication expenses and specific database upkeep. A thorough multi-user field assessment offers an accurate evaluation of deployment dependability in educational settings.