RFID Based Access Control System
Tech Stack
Overview
This was my capstone project for the Computer Engineering Department at Bahcesehir University. The system is a complete RFID-based access control solution that combines hardware (Arduino + RFID reader) with a mobile management app. Authorized RFID cards grant access by triggering an electronic lock, while every access attempt — successful or denied — is logged with timestamps. The companion mobile app allows administrators to manage authorized cards, view real-time access logs, add or revoke cards remotely, and receive notifications for denied access attempts. The hardware communicates with a Firebase backend over WiFi, and the mobile app reads from the same database for real-time sync. The project demonstrates the full IoT stack: embedded hardware programming, wireless communication, cloud backend, and mobile client.
Challenges
- •Ensuring reliable communication between the Arduino hardware and Firebase backend over WiFi with intermittent connectivity
- •Minimizing the latency between card tap and lock response — anything over 1 second feels broken for physical access
- •Designing the system to fail securely: what happens when WiFi is down or Firebase is unreachable?
Solutions
- •Implemented a local cache on the Arduino that stores the last 100 authorized card IDs, syncing with Firebase when connectivity is available and falling back to the local cache when offline
- •Optimized the RFID read-to-unlock pipeline to under 500ms by doing local card validation first and logging the event asynchronously
- •Designed a fail-secure mode where the local card cache handles authentication offline, with access logs queued and batch-synced when connectivity returns
Results
University capstone project - IoT-based security solution