ESP32 Voucher Generator

Project Overview

This repository contains the source code for a project designed to integrate an ESP32 device into a voucher-based internet access system. This project is built around two main components:

1. Raspberry Pi 3B+:
   • Runs OpenWrt with OpenNDS to provide a captive portal.
   • Handles voucher validation and internet access control.
   • Includes a Python-based MQTT server for communication with the ESP32.
2. ESP32 (LilyGO T-Display-S3):
   • Generates unique internet access vouchers.
   • Displays vouchers on its built-in screen.
   • Prints vouchers to a network-connected printer.
   • Sends voucher data to the Raspberry Pi via MQTT.

Roadmap / TODOs

• [-] WiFi Configuration Portal:
  • Implement a web interface for configuring WiFi credentials.
  • Encrypt NVS.
• Raspberry Pi Integration:
  • Finalize MQTT communication between the ESP32 and the Raspberry Pi.
• Printing Integration:
  • Implement network printing for vouchers.
  • Test compatibility with multiple printer models.
• UI Enhancements:
  • Add additional details such as expiration times to vouchers.
• Security Enhancements:
  • Secure MQTT communication.

Key Features

• Voucher Management:
  • Generate unique internet access vouchers.
  • Display vouchers on the ESP32 screen and print them to a network printer.
  • Send vouchers to the Raspberry Pi via MQTT for captive portal integration.
• WiFi Configuration Portal:
  • Allows users to configure WiFi credentials through a web interface hosted by the ESP32.
  • Credentials are securely stored using the ESP32's non-volatile storage (NVS).
• QR Code Display:
  • Displays the network credentials and configuration portal URL as a QR code on the ESP32's screen.
• Captive Portal Integration:
  • Utilizes OpenNDS on the Raspberry Pi to manage guest internet access.

Getting Started

Prerequisites

• Hardware:
  • ESP32 (LilyGO T-Display-S3 recommended).
  • Raspberry Pi 3B+ with OpenWrt installed.
• Software:
  • PlatformIO (installed as a VSCode extension or standalone).
  • Python environment for the MQTT server on the Raspberry Pi.

Installation

1. Clone this repository:

   git clone <repository-url>
   cd voucher_maker

2. Open the project in your preferred IDE (e.g., VSCode with PlatformIO).
3. Configure the platformio.ini file if necessary (e.g., to change upload settings).
4. Build and upload the firmware to your ESP32:

   platformio run --target upload

Usage

1. Power On: Ensure the ESP32 is powered on and connected.
2. WiFi Configuration:
   • When no WiFi credentials are found, the ESP32 starts as an access point.
   • Scan the QR code displayed on the ESP32 screen using a mobile device.
   • Follow the link to the configuration portal and fill out the form to set WiFi credentials.
3. Voucher Generation:
   • Trigger voucher generation (e.g., via a button press).
   • View the voucher code on the ESP32 screen or print it to a network printer.
   • The voucher is sent to the Raspberry Pi for captive portal integration.

License

This project is licensed under the MIT License.