BLE Attendance System

Overview

Taking attendance in large classrooms consumes valuable time every hour. Proxy attendance is common, and faculty rarely get real-time visibility into student activity. Our team set out to build a system that could automate this entire process in the background — no queues, no manual entry, no errors.

The result is a Bluetooth Low Energy (BLE) Attendance System, where every student’s phone becomes a secure digital identity. An ESP32 device inside the classroom scans BLE packets, validates UUIDs, and pushes the data to Firebase for instant attendance monitoring.

• Fully automated attendance system
• Each student’s phone broadcasts a unique UUID
• ESP32 scans & verifies active students
• Secure cloud sync via Firebase
• Teachers get real-time dashboards & analytics

Technologies Used

• Android Studio (Kotlin): Mobile App + BLE UUID Broadcasting
• ESP32 (Arduino/C++): BLE Scanner + Data Filtering
• Firebase: Real-time Database + Authentication + Analytics

Methodology

• Student enters the classroom with the mobile app running
• App continuously advertises a secure BLE UUID
• ESP32 detects UUID & logs timestamp
• Record is pushed instantly to Firebase
• Teacher dashboard updates in real-time

Teacher Panel: A dynamic attendance dashboard displaying present/absent students, timestamps, and attendance history.

My Role

• Implemented BLE advertising in the Android app
• Built ESP32-side scanning, filtering, and UUID validation
• Integrated Firebase real-time sync and database structure
• Created demo dashboards and documentation

Challenges & Solutions

• Unstable BLE Signal Strength: Solved by averaging RSSI and using stability thresholds.
• Duplicate UUID Detection: Added rolling time windows to prevent false positives.
• Battery Drain on Phones: Switched to low-energy advertising mode.
• Cloud Sync Latency: Optimized Firebase write operations.

Feasibility & Viability

• Technological: BLE works on nearly all modern smartphones.
• Operational: Easy deployment — just power the ESP32 unit.
• Legal: Only UUIDs are stored; no personal identifiers.
• Economical: Hardware cost ≈ ₹250–₹350 per classroom.
• Social: Saves time and encourages transparency.

Impacts

• Automates attendance & eliminates manual errors
• Real-time visibility for faculty
• Stops proxy attendance
• Provides daily, weekly, and monthly insights

Benefits

• Social: Transparent and error-free
• Economical: Scalable & affordable
• Eco-friendly: Paperless
• Contactless: Fully automated
• Coverage: Multiple BLE nodes for large rooms

Outcome & Future Scope

• Achieved reliable detection with over 95% accuracy
• Significant reduction in manual workload for faculty
• Successfully demonstrated in a classroom environment
• Plan to add offline caching & multi-classroom sync

Our Team

Gallery

Demo