BLE Attendance Prototype

Prototype implementation of a classroom attendance system using BLE proximity + biometrics.

Stack

• Mobile: Flutter (single app with Teacher/Student roles)
• Backend: FastAPI
• Database: PostgreSQL (Docker compose provided)

Repository layout

• backend/ - FastAPI APIs, models, seed script, docker compose
• mobile/ble_attendance_mobile/ - Flutter app source
• ARCHITECTURE.md - architecture and scope notes

Prototype capabilities implemented

• Role-based register/login (teacher/student)
• Teacher starts/ends sessions and advertises BLE token
• Student scans BLE, sends periodic RSSI detections
• Presence ratio computed from detection windows
• Student biometric finalization endpoint flow
• Teacher detections + attendance summary endpoints
• Teacher manual attendance override endpoint

Test credentials

Seeded accounts (from backend/scripts/seed_demo.py):

• Teacher: T001 / Pass@123
• Student: 25CE099 / Pass@123
• Student: 25CE100 / Pass@123
• Student: D26CE045 / Pass@123

Backend quick start

cd backend
docker compose up -d
cd ..
python3 -m venv .venv
.venv/bin/pip install -r backend/requirements.txt
PYTHONPATH=backend .venv/bin/python backend/scripts/seed_demo.py
PYTHONPATH=backend .venv/bin/uvicorn app.main:app --host 0.0.0.0 --port 8000 --reload --app-dir backend

API docs: http://127.0.0.1:8000/docs

Temporary LAN test setup (same Wi-Fi)

1. On laptop, start backend with --host 0.0.0.0 (command above).
2. Find laptop IP (example 192.168.1.7) using ip a.
3. On phone browser, verify http://<laptop-ip>:8000/health.
4. In app login screen, set Server URL to http://<laptop-ip>:8000.
5. Tap Test Connection, then login.

Mobile quick start

cd mobile/ble_attendance_mobile
flutter pub get
flutter run

For physical Android devices on same LAN:

flutter run --dart-define=API_BASE_URL=http://<your-laptop-ip>:8000

Build APK (smaller ARM only)

Build split release APKs for armeabi-v7a and arm64-v8a:

cd mobile/ble_attendance_mobile
flutter build apk --release --split-per-abi --target-platform android-arm,android-arm64

Package them with app name + version iteration in filename:

./scripts/package_release_apks.sh v0.1.3

Output files (raw + packaged):

• mobile/ble_attendance_mobile/build/app/outputs/flutter-apk/app-armeabi-v7a-release.apk
• mobile/ble_attendance_mobile/build/app/outputs/flutter-apk/app-arm64-v8a-release.apk
• mobile/ble_attendance_mobile/build/app/outputs/flutter-apk/BLE_Attendance_v0.1.3_armeabi-v7a_release.apk
• mobile/ble_attendance_mobile/build/app/outputs/flutter-apk/BLE_Attendance_v0.1.3_arm64-v8a_release.apk

Local build prerequisites (Linux)

• Flutter SDK installed and in PATH
• Java 17 JDK available for Gradle builds
• Android SDK + licenses accepted (platform-tools, platform/build-tools, NDK)
• Docker running for local PostgreSQL

Built APK

Release assets currently publish release APKs for ARM only:

• app-armeabi-v7a-release.apk
• app-arm64-v8a-release.apk