IoT-Enabled Digital Notice Board

A realtime cloud-connected digital notice board system built using ESP32, Firebase, Flutter, and HUB75E RGB LED Matrix Display for wireless notice management and realtime display synchronization.

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📌 Project Overview

Traditional notice boards require manual updates, consume paper, and cannot provide realtime remote communication. This project solves these limitations by implementing an IoT-based digital notice management system capable of publishing notices remotely through cloud communication.

The system uses:

• Flutter Mobile Application for notice management
• Firebase Cloud Services for realtime synchronization
• ESP32 Microcontroller for embedded processing
• HUB75E RGB LED Matrix Display for realtime visual output

Whenever a notice is published from the mobile application, the ESP32 automatically fetches updated data from Firebase Realtime Database and displays it on the LED matrix display in realtime.

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🚀 Features

• Realtime cloud synchronization
• Wireless notice publishing
• Firebase Authentication system
• Email verification support
• Realtime display updates
• HUB75E RGB LED matrix rendering
• Scrolling text display
• Dynamic brightness control
• Text color customization
• Border style customization
• NTP-based realtime clock display
• Automatic notice expiry handling
• ESP32 remote restart support
• DMA-based smooth rendering

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🛠️ Technologies Used

Mobile Application

• Flutter
• Dart

Cloud Services

• Firebase Authentication
• Firebase Realtime Database
• Cloud Firestore

Embedded System

• ESP32
• Arduino IDE
• Firebase ESP Client Library

Display System

• HUB75E RGB LED Matrix
• ESP32-HUB75-MatrixPanel-I2S-DMA Library

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🧩 System Architecture

Flutter App
     │
     ▼
Firebase Cloud Services
     │
     ▼
ESP32 Controller
     │
     ▼
HUB75E RGB LED Matrix Display

📱 Mobile Application Features

• User Registration
• Secure Login
• Email Verification
• Forgot Password
• Notice Publishing
• Display Settings Management
• Realtime Notice Monitoring
• Brightness Control
• Scroll Speed Management
• Notice Expiry Configuration

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🔌 Hardware Components

Component	Description
ESP32	Main IoT Controller
HUB75E RGB LED Matrix	Display Output Device
Power Supply	5V External Supply
WiFi Network	Cloud Communication
USB Cable	ESP32 Programming

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🔗 ESP32 and HUB75E Connections

HUB75E Signal	ESP32 GPIO
R1	GPIO 25
G1	GPIO 26
B1	GPIO 27
R2	GPIO 14
G2	GPIO 12
B2	GPIO 13
A	GPIO 23
B	GPIO 19
C	GPIO 5
D	GPIO 2
E	GPIO 15
LAT	GPIO 4
OE	GPIO 16
CLK	GPIO 18

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☁️ Firebase Realtime Database Structure

{
  "noticeBoard": {
    "noticeBoardId": {

      "Notice": {
        "message": "Welcome",
        "category": "NOTICE",
        "symbol": "",
        "expiryAt": "0"
      },

      "Settings": {

        "settings": {
          "bodyTextColor": "blue",
          "headerTextColor": "red",
          "borderColor": "green",
          "borderStyle": "single",
          "brightness": 80,
          "scrollSpeed": 3,
          "displayMode": "scroll"
        },

        "commands": {
          "resetDisplay": false,
          "restartDevice": false
        }

        "wifi": {
          "ssid": "wifi_name",
          "password": "wifi_password"
        }

      }
    }
  }
}

⏰ Notice Expiry Logic

The system uses:

• NTP time synchronization
• Epoch timestamp comparison

Expired notices are automatically removed from:

• ESP32 display
• Firebase Realtime Database

After expiry, the system automatically switches to realtime clock mode.

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📡 Realtime Communication Workflow

1. User publishes notice from Flutter app
2. Firebase updates Realtime Database
3. ESP32 fetches updated notice
4. HUB75E display updates instantly
5. Notice expiry monitored continuously
6. Clock mode activated after expiry

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📷 Project Modules

• Flutter Mobile Application
• Firebase Cloud Backend
• ESP32 Firmware
• HUB75E Display Interface
• Realtime Synchronization System
• NTP Clock System
• DMA-Based Rendering Engine

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📄 Technical Project Report

The complete technical documentation for the IoT-Enabled Digital Notice Board project is available in the detailed project report.

The report includes:

• System Architecture
• Hardware Design
• Software Implementation
• Firebase Integration
• ESP32 Firmware Logic
• Testing and Results
• Communication Workflow
• Future Scope and Analysis

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⚠️ Challenges Faced

• HUB75E driver IC compatibility
• Firebase SSL communication stability
• DMA rendering optimization
• Memory management during JSON parsing
• Stable realtime synchronization

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📈 Future Improvements

• Multi-display synchronization
• Web dashboard integration
• OTA firmware updates
• Voice announcement system
• MQTT communication support
• Smart campus integration

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📚 References

• ESP32 Documentation
• Firebase Documentation
• Flutter Documentation
• Firebase ESP Client Library
• HUB75 RGB Matrix Documentation

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👨‍💻 Lead Developer

Rohit Singh

• GitHub Profile
• Portfolio

Primary Responsibilities

• Flutter Mobile Application Development
• Firebase Integration & Cloud Architecture
• ESP32 Firmware Development
• HUB75E Display Integration
• Realtime Synchronization Logic
• System Architecture Design
• Technical Documentation

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🤝 Academic Project Context

Developed as part of a 4th Semester Micro Project
Department of Electronics and Communication Engineering

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📄 License

This project is developed for academic and educational purposes.