CESI IoT — Connected Access & Attendance

This repository contains a prototype for modernizing room access and attendance tracking at the CESI Caen campus. The project uses a hybrid Edge+Cloud IoT approach to replace physical keys and paper attendance with NFC-based identification, local access validation, and centralized attendance logging.

Guidelines:

• All code and comments (including TODOs) MUST be written in ENGLISH.

• Put test code and experimental examples under 04_Developpement_Code/ (for example 04_Developpement_Code/tests/).

• Keep TODOs short, actionable, and include an owner and a target date when possible. Example TODO usage:

  // TODO(owner): Improve NFC debounce handling — investigate interrupt-based approach.

Table of Contents

• Architecture
• Hardware Components
• Communication Protocols
• Key Features & KPIs
• Setup & Deployment

Architecture

The system uses a hybrid (Edge + Cloud) approach to balance responsiveness and centralized management:

• Edge Processing (Local): Local access validation and unlocking with sub-2s response. The edge can operate in degraded mode when the cloud is unavailable.
• Cloud Centralization: Synchronizes user profiles, stores timestamped attendance records, and provides analytics dashboards.

Hardware Components

The prototype is split into two primary subsystems (Grove-compatible components for rapid prototyping):

1. Central Badge Reader (Badgeuse) — a mains-powered kiosk that handles high-volume interactions.

   • Wio Terminal
   • XBee Module + Support Bee
   • Grove NFC Module

2. Smart Lock (Serrure Connectée) — a battery-powered lock mounted on doors.

   • Arduino Uno R4
   • Grove Base Shield
   • XBee Module + Support Bee
   • Grove NFC Module
   • Grove LED Modules (red/green status)

Communication Protocols

• Local links: XBee network between locks and the central badge reader.
• Identification: NFC (physical badges or smartphone emulation).
• Server sync: MQTT or CoAP (lightweight protocols with QoS options) between the central badge reader and the cloud server.

Key Features & KPIs

• Ultra-Low Latency: Identification → validation → unlock in under 2 seconds.
• Automated Attendance: Timestamped, centralized logs that remove paper attendance sheets.
• High Availability: Target >95% uptime; local caching when the cloud is unreachable.
• Security: Role-based access control (RBAC), unique IDs, and encrypted transport.

Setup & Deployment

This README is a living document. When the codebase stabilizes, add:

• Compilation and dependency instructions for edge devices and gateway software.
• MQTT broker configuration and topics schema.
• How to provision users and roles (ERP integration notes).

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