Smart Card Access Control System

This repository contains the firmware for a Smart Card Access Control System, developed as "Projeto 2" for the UFSC - EEL7030 Microprocessadores course.

🚀 Check out the Simulator!

You can explore and interact with a live simulation of this project directly in your browser: Smart Card Access Control System Simulator

Project Overview

The core of this system is an ESP32-C3 microcontroller which acts as the central processing unit for the door lock. It interacts with a SmartCard EEPROM via an I2C protocol and communicates with a central server over Wi-Fi using HTTP POST requests.

When a guest performs a check-in, a 16-character random ID is generated and associated with the room number. This ID is then registered in the hotel's database and written to the first two pages (first 16 bytes) of a SmartCard EEPROM.

Key Features:

• Smart Card Interaction: Reads the 16-character ID from the first two pages of the SmartCard EEPROM (base addresses 0x00 and 0x08) upon card insertion, which is detected by a limit switch button ($\mathbf{B_{FC}}$).
• Wi-Fi Connectivity: Connects to the hotel's Wi-Fi network.
• Server Communication: Sends the SmartCard ID and room number to a central server via HTTP POST requests for validation.
• Access Decision: Based on the server's positive or negative response, the ESP32-C3 decides whether to grant or deny access.
• Door Lock Simulation: A red LED, connected to GPIO 9, simulates the door lock release system, remaining lit for 2 seconds to open the lock.
• Timestamping: Records a 64-bit (8 bytes) timestamp of each access attempt (regardless of outcome) onto page 4 (base address 0x18) of the SmartCard.
• User Feedback (LCD Display): An LCD display provides real-time status updates via I2C, such as "Conectando ao Wi-Fi" (Connecting to Wi-Fi), "Aguardando Cartão" (Waiting for Card), "Verificando Cartão" (Verifying Card), "Acesso Liberado" (Access Granted), or "Acesso Negado" (Access Denied).
• System Status (Green LED): A green LED, connected to GPIO 0, provides visual feedback on the system's state through different blinking patterns: slow blinking when disconnected, solid when connected, single flash on read start, double flash on access granted, and six flashes on access denied.

Hardware Setup

The project utilizes the ESP32-C3 microcontroller, an EEPROM SmartCard, a SmartCard reader, an LCD display, a red LED, a green LED, and a limit switch button ($\mathbf{B_{FC}}$) to detect card insertion. A circuit diagram illustrating the proposed hardware for testing is included in the project documentation.

Connections Diagram

Here's the Fritzing diagram showing the connections for the SmartCard and LCD with the ESP32-C3:

Development

The firmware is written in C and built upon the Espressif IoT Development Framework (ESP-IDF). It leverages the FreeRTOS operating system for task management.