ESP32-S3 Multi-Task Environmental Monitoring System

A professional embedded systems project featuring real-time environmental monitoring with temperature and humidity sensing, visual indicators, web-based control, and TinyML-powered anomaly detection. Built on ESP32-S3 using FreeRTOS for robust multi-tasking architecture.

🎯 What Does This System Do?

For End Users

This is a smart environmental monitoring system that watches the temperature and humidity in your room and provides visual alerts and web-based control:

🌡️ Temperature Monitoring

Continuously measures room temperature
LED blinks at different speeds based on temperature:
- Slow blink = Cold (below 20°C)
- Medium blink = Normal (20-30°C)
- Fast blink = Hot (30-40°C)
- Always ON = Critical! (above 40°C)

💧 Humidity Monitoring

Tracks room humidity levels
NeoPixel changes color to show humidity:
- Blue = Too dry (below 40%)
- Green = Comfortable (40-60%)
- Yellow = Getting humid (60-80%)
- Red = Too wet (above 80%)

** Web Dashboard Access**

Connect your phone/laptop to WiFi: ESP32-S3-LAB (password: 12345678)
Open browser to: http://192.168.4.1
See live temperature, humidity, and system status
Control 4-LED light bar with 5 different modes:
- OFF, BAR graph, Rainbow animation, SOS emergency, or Blinking

🚨 Fire Alert System

Enable "Fire Alert Auto Mode" from the dashboard
Set your danger temperature (e.g., 45°C)
System automatically switches to SOS mode when temperature exceeds threshold
Automatically returns to normal when temperature is safe
Perfect for fire prevention or equipment overheating alerts

🔧 Remote Control

Adjust temperature/humidity thresholds from anywhere
Control GPIO pins remotely
Switch between WiFi modes (Access Point or connect to your home WiFi)

🧠 Smart Anomaly Detection

Built-in AI monitors sensor patterns
Detects unusual temperature/humidity combinations
Helps identify sensor failures or environmental issues

📊 16x2 LCD Display

Shows current temperature and humidity
Displays classification bands (COLD/NORMAL/HOT/CRITICAL)
No phone needed - see status at a glance

📋 Table of Contents

What Does This System Do?
Features
System Architecture
Hardware Requirements
Pin Configuration
Software Architecture
Task Synchronization
Web Dashboard
Installation
Configuration
Usage
API Reference
Project Structure
Contributing
Troubleshooting
License

✨ Features

Core Functionality

Real-time Environmental Monitoring: DHT20 I2C sensor for accurate temperature and humidity readings
Multi-Task Architecture: 6 concurrent FreeRTOS tasks with semaphore-based synchronization
Visual Indicators:
- Temperature-responsive LED blinking patterns
- Humidity-based NeoPixel color indication
- 4-pixel NeoPixel UI bar with multiple display modes
LCD Display: 16x2 I2C LCD showing real-time sensor data and system status
Web Dashboard: Full-featured web interface for monitoring and configuration
WiFi Connectivity: Access Point and Station modes with seamless switching
TinyML Integration: On-device machine learning for anomaly detection
GPIO Control: Remote GPIO manipulation via web API

Advanced Features

Configurable temperature and humidity thresholds
Real-time task performance monitoring
SOS emergency mode for NeoPixel strip
Fire alert system with customizable behavior
Comprehensive telemetry and diagnostics

🏗️ System Architecture

Overview

The system employs a modular, event-driven architecture using FreeRTOS for task management and binary semaphores for inter-task communication.

┌─────────────────────────────────────────────────────────────────────┐
│                        ESP32-S3 System Core                         │
├─────────────────────────────────────────────────────────────────────┤
│                                                                     │
│  ┌──────────┐  ┌──────────┐  ┌──────────┐  ┌──────────┐             │
│  │  Task 1  │  │  Task 2  │  │  Task 3  │  │  Task 4  │             │
│  │  DHT20   │→→│   LED    │→→│ NeoPixel │  │ NeoPixel │             │
│  │  Sensor  │  │  Control │  │   Hum    │  │  UI Bar  │             │
│  └────┬─────┘  └────┬─────┘  └────┬─────┘  └──────────┘             │
│       │             │             │                                 │
│       │    ┌────────┴─────────────┘                                 │
│       └────┤                                                        │
│            ↓                                                        │
│       ┌──────────┐        ┌──────────┐                              │
│       │  Task 5  │        │  Task 6  │                              │
│       │   LCD    │        │  TinyML  │                              │
│       │ Display  │        │ Anomaly  │                              │
│       └──────────┘        └──────────┘                              │
│                                                                     │
├─────────────────────────────────────────────────────────────────────┤
│                      WiFi + Web Server                              │
│                   HTTP API + Dashboard                              │
└─────────────────────────────────────────────────────────────────────┘

🔧 Hardware Requirements

Essential Components

Component	Model/Specification	Quantity	Purpose
Microcontroller	ESP32-S3 (YOLO Uno board)	1	Main processor with WiFi
Temperature/Humidity Sensor	DHT20 (I2C)	1	Environmental sensing
LCD Display	16x2 I2C LCD (0x21)	1	Status display
LED	Standard LED (any color)	1	Temperature indicator
NeoPixel Strip	WS2812B (1 pixel)	1	Humidity indicator (GPIO 45)
NeoPixel Strip	WS2812B (4 pixels)	1	UI Bar (GPIO 6)

Specifications

Operating Voltage: 3.3V logic, 5V for NeoPixels
Power Consumption: ~500mA peak (with all NeoPixels on)
I2C Speed: Standard mode (100 kHz)
WiFi: 2.4 GHz 802.11 b/g/n

📍 Pin Configuration

GPIO Mapping

// I2C Bus (Shared by DHT20 and LCD)
SDA_PIN        = 11  // I2C Data
SCL_PIN        = 12  // I2C Clock

// Outputs
LED_GPIO       = 48  // Temperature indicator LED
NEOPIXEL_HUM   = 45  // Single pixel humidity indicator
NEOPIXEL_UI    = 6   // 4-pixel UI bar

// I2C Addresses
DHT20_ADDR     = 0x38 (default)
LCD_ADDR       = 0x21

Pin Diagram

                        ESP32-S3
                    ┌──────────────┐
                    │              │
    DHT20 SDA   ────┤ 11 (SDA)     │
    DHT20 SCL   ────┤ 12 (SCL)     │
    LCD SDA     ────┤              │
    LCD SCL     ────┤              │
                    │              │
    LED (-)     ────┤ 48 (LED)     │
                    │              │
    NeoHum DIN  ────┤ 45 (NEO_H)   │
    NeoUI DIN   ────┤ 6  (NEO_UI)  │
                    │              │
                    │ USB-C        │──── Power & Serial
                    └──────────────┘

⚠️ Warning: GPIO 11, 12, 6, 45, and 48 are protected in the web GPIO control interface to prevent accidental system disruption.

Hardware Gallery

Complete System Assembly

Full system with ESP32-S3, DHT20 sensor, LCD display, relay, and NeoPixel strips

Hardware Components

YOLO UNO ESP32-S3 Development Board Dual-core @ 240MHz, 512KB SRAM, 8MB Flash Built-in LED (GPIO 48) & NeoPixel (GPIO 45)	DHT20 Temperature & Humidity Sensor I2C Address: 0x38 ±0.3°C accuracy, ±3% RH accuracy
LCD 16x2 with I2C Backpack I2C Address: 0x21 Displays temperature, humidity, and bands	NeoPixel 4-LED Strip (WS2812B) GPIO 6 - UI Bar visualization Addressable RGB LEDs

System Wiring Diagram

Complete GPIO pin assignments and I2C bus connections

Key Connections:

I2C Bus (GPIO 11/12): Shared between DHT20 (0x38) and LCD (0x21)
GPIO 48: Built-in LED for temperature indication
GPIO 45: Built-in NeoPixel for humidity indication
GPIO 6: External NeoPixel 4-LED strip for UI bar
USB-C: Power (5V) and serial communication (115200 baud)

💻 Software Architecture

Module Organization

src/
├── main.cpp                    # Entry point & main loop
├── config/
│   ├── config.h               # System constants & pin definitions
│   ├── system_types.h         # Data structures & enumerations
│   └── system_types.cpp       # Helper functions & globals
├── hardware/
│   ├── hardware_manager.h     # Hardware object declarations
│   └── hardware_manager.cpp   # Hardware initialization
├── tasks/
│   ├── tasks.h               # Task declarations & documentation
│   ├── tasks.cpp             # Task creation & management
│   ├── task1_sensor.cpp      # DHT20 sensor reading
│   ├── task2_led_neopixel.cpp # LED & NeoPixel control
│   ├── task3_lcd.cpp         # LCD display updates
│   └── task5_tinyml.cpp      # TinyML inference
├── web/
│   ├── web_server.h          # Web server declarations
│   ├── web_server.cpp        # HTTP handlers & routing
│   └── web_pages.h           # HTML dashboard
└── ml/
    ├── tinyml.h              # TensorFlow Lite includes
    └── dht_anomaly_model.h   # Trained ML model

Key Technologies

Framework: Arduino (ESP32-S3 core)
RTOS: FreeRTOS (built-in with ESP32)
Web Server: ESPWebServer library
ML Framework: TensorFlow Lite Micro
Libraries:
- DHT20 sensor library (v0.3.1)
- Adafruit NeoPixel (v1.15.2)
- LiquidCrystal_I2C (v1.1.4)
- TensorFlowLite_ESP32 (v1.0.0)

📊 System Architecture Diagrams

Task Communication Flow

Producer-Consumer pattern with binary semaphore signaling between tasks

Key Points:

Task 1 (DHT20 Sensor) acts as producer, reading sensor every 500ms
Tasks 2, 3, 5 act as consumers, waking only when semaphore signaled
Zero polling: Consumer tasks sleep with 0% CPU usage until needed
<1ms response: Semaphore wakeup latency under 1 millisecond
99.86% efficiency: Eliminates 99.86% of unnecessary task wakeups vs polling

System Boot Sequence

Complete initialization timeline from power-on to operational state (2.1 seconds)

Boot Phases:

Core Init (0-50ms): Bootloader, Arduino framework, Serial
Hardware Setup (50-200ms): Semaphores, I2C, DHT20, LCD, NeoPixels
Network Layer (200-2000ms): WiFi AP, HTTP server, 11 API endpoints
Task Creation (2000-2100ms): 6 FreeRTOS tasks with priorities and stacks
Scheduler Active (2100ms+): FreeRTOS scheduler takes control

Task Execution Timeline

1-second window showing priority-based preemptive scheduling in action

Observations:

Task 1 (P:3) preempts all lower-priority tasks when it wakes
88% CPU idle time - system highly efficient, tasks sleep when not needed
Deterministic behavior - high-priority tasks complete within 1-2ms of wakeup
No starvation - even lowest-priority tasks get sufficient CPU time

🔄 Task Synchronization

The system uses binary semaphores for efficient inter-task communication with minimal CPU overhead.

Semaphore Flow Diagram

┌──────────────┐
│   Task 1     │ (Priority 3 - Highest)
│   DHT20      │
│   Sensor     │
└──────┬───────┘
       │
       │ Every 500ms: Read sensor
       │
       ├─── IF temperature band changed ───→ semBandChanged
       │                                           ↓
       │                                    ┌──────────────┐
       │                                    │   Task 2     │ (Priority 2)
       │                                    │   LED Blink  │
       │                                    └──────────────┘
       │
       ├─── IF humidity band changed ──────→ semHumChanged
       │                                           ↓
       │                                    ┌──────────────┐
       │                                    │   Task 3     │ (Priority 2)
       │                                    │  NeoPixel H  │
       │                                    └──────────────┘
       │
       └─── ALWAYS ────────────────────────→ semLcdUpdate
                                                   ↓
                                            ┌──────────────┐
                                            │   Task 5     │ (Priority 1)
                                            │   LCD        │
                                            └──────────────┘

Note: Task 4 (NeoPixel UI) and Task 6 (TinyML) run independently

Synchronization Details

Semaphore: `semBandChanged`

Producer: Task 1 (Sensor)
Consumer: Task 2 (LED)
Trigger: Temperature band transition (COLD ↔ NORMAL ↔ HOT ↔ CRITICAL)
Behavior: Task 2 blocks until new temperature band is detected

Semaphore: `semHumChanged`

Producer: Task 1 (Sensor)
Consumer: Task 3 (NeoPixel Humidity)
Trigger: Humidity band transition (DRY ↔ COMFORT ↔ HUMID ↔ WET)
Behavior: Task 3 blocks until new humidity band is detected

Semaphore: `semLcdUpdate`

Producer: Task 1 (Sensor)
Consumer: Task 5 (LCD)
Trigger: Every sensor reading (500ms interval)
Behavior: LCD updates continuously with latest readings

🎨 Web Dashboard

Access Information

Default SSID: ESP32-S3-LAB
Default Password: 12345678
Dashboard URL: http://192.168.4.1
Port: 80 (HTTP)

Features

1. Real-Time Monitoring

Live temperature and humidity readings
Task execution counters
Last execution timestamps for each task
TinyML anomaly scores

2. Threshold Configuration

Configure temperature bands:

COLD: < T_COLD_MAX (default: 20°C)
NORMAL: T_COLD_MAX - T_NORMAL_MAX (default: 20-30°C)
HOT: T_NORMAL_MAX - T_HOT_MAX (default: 30-40°C)
CRITICAL: > T_HOT_MAX (default: > 40°C)

Configure humidity bands:

DRY: < H_DRY_MAX (default: 40%)
COMFORT: H_DRY_MAX - H_COMF_MAX (default: 40-60%)
HUMID: H_COMF_MAX - H_HUMID_MAX (default: 60-80%)
WET: > H_HUMID_MAX (default: > 80%)

3. NeoPixel UI Control

OFF Mode: All pixels disabled
BAR Mode: 4-LED bar graph showing humidity percentage
DEMO Mode: Rainbow color animation
SOS Mode: Emergency SOS pattern (··· ─── ···)
BLINK Mode: Synchronized blinking pattern

4. WiFi Configuration

Switch between Access Point and Station modes
Configure SSID and password
View current connection status

5. GPIO Control

Remote GPIO manipulation (pins 0-48)
Safety lockout for critical system pins
Real-time state control (HIGH/LOW)

API Endpoints

GET  /              → Dashboard HTML page
GET  /state         → JSON with all system state
POST /set           → Update thresholds (query params: tcold, tnorm, thot, hdry, hcomf, hhum)
POST /ui/off        → Set NeoPixel UI to OFF mode
POST /ui/bar        → Set NeoPixel UI to BAR mode
POST /ui/demo       → Set NeoPixel UI to DEMO mode
POST /ui/sos        → Set NeoPixel UI to SOS mode
POST /ui/blink      → Set NeoPixel UI to BLINK mode
POST /fire-alert    → Control fire alert system (param: enable=0|1)
POST /wifi          → Configure WiFi (params: mode, ssid, pass)
POST /gpio          → Control GPIO (params: pin, state)

Web Dashboard Screenshots

Main Dashboard Real-time sensor readings, band classification, task telemetry, and TinyML anomaly score	Configuration Page Runtime threshold adjustment for temperature and humidity bands + WiFi settings
Control Page NeoPixel UI mode selection (OFF/BAR/DEMO/SOS) and GPIO remote control (40 pins)	Landing Page System overview with quick access to all features and documentation

Example State Response

{
  "ms": 123456,
  "tC": 25.3,
  "rh": 55.2,
  "tBand": "NORMAL",
  "hBand": "COMFORT",
  "led": 1,
  "blink_on": 300,
  "blink_off": 300,
  "giveTemp": 5,
  "takeTemp": 5,
  "giveHum": 3,
  "takeHum": 3,
  "tcold": 20.0,
  "tnorm": 30.0,
  "thot": 40.0,
  "hdry": 40.0,
  "hcomf": 60.0,
  "hhum": 80.0,
  "dht_runs": 247,
  "led_runs": 1024,
  "neo_runs": 12,
  "lcd_runs": 247,
  "tiny_score": 0.023,
  "tiny_runs": 49,
  "uiMode": 1,
  "wifiMode": "ap"
}

🚀 Installation

Prerequisites

Install VS Code: Download here
Install PlatformIO Extension: Search "PlatformIO IDE" in VS Code Extensions
USB Driver: Install ESP32-S3 USB drivers for your OS
Git: For cloning the repository

Step-by-Step Setup

1. Clone the Repository

git clone https://github.com/leonathn/MidtermProject_ESP32_PlatformIO.git
cd MidtermProject_ESP32_PlatformIO

2. Open in VS Code

code .

Or: File → Open Folder → Select project directory

3. Install Dependencies

PlatformIO will automatically install required libraries on first build:

DHT20 sensor library
Adafruit NeoPixel
LiquidCrystal_I2C
TensorFlowLite_ESP32

4. Connect Hardware

Follow the Pin Configuration section to wire components.

5. Build Project

Press Ctrl+Alt+B (Windows/Linux) or Cmd+Alt+B (Mac)
Or click the checkmark (✓) icon in the bottom toolbar
Wait for compilation to complete

6. Upload to ESP32-S3

Connect ESP32-S3 via USB-C
Press Ctrl+Alt+U or click the arrow (→) icon
Monitor serial output with Ctrl+Alt+S

7. Verify Installation

Look for this output in the serial monitor:

╔════════════════════════════════════════════════╗
║   ESP32-S3 Multi-Task Environmental Monitor    ║
║   FreeRTOS + DHT20 + LCD + NeoPixel + Web      ║
╚════════════════════════════════════════════════╝

[HW] Hardware initialized successfully
[SYNC] Semaphores created successfully
[WiFi] AP IP: 192.168.4.1
[WEB] Web server started on port 80
[TASKS] All tasks created successfully

╔════════════════════════════════════════════════╗
║              System Ready                      ║
║  Connect to: ESP32-S3-LAB (password: 12345678) ║
║  Dashboard: http://192.168.4.1                 ║
╚════════════════════════════════════════════════╝

⚙️ Configuration

Compile-Time Configuration

Edit src/config/config.h:

/* WiFi Settings */
#define AP_SSID_DEFAULT "ESP32-S3-LAB"
#define AP_PASS_DEFAULT "12345678"

/* Default Thresholds */
#define DEFAULT_T_COLD_MAX   20.0f
#define DEFAULT_T_NORMAL_MAX 30.0f
#define DEFAULT_T_HOT_MAX    40.0f

#define DEFAULT_H_DRY_MAX    40.0f
#define DEFAULT_H_COMF_MAX   60.0f
#define DEFAULT_H_HUMID_MAX  80.0f

/* Task Timing */
#define DHT_READ_INTERVAL_MS    500   // Sensor polling rate
#define UI_STRIP_UPDATE_MS      120   // NeoPixel UI refresh rate
#define TINYML_INFERENCE_MS     5000  // ML inference interval

/* Task Stack Sizes */
#define TASK_DHT_STACK_SIZE     4096
#define TASK_LED_STACK_SIZE     3072
#define TASK_TINYML_STACK_SIZE  8192  // Larger for ML operations

Runtime Configuration

All thresholds can be modified via the web dashboard without recompiling.

Custom Board Configuration

The project uses a custom board definition: boards/yolo_uno.json Modify platformio.ini if using a different ESP32-S3 board:

[env:combined]
board = esp32-s3-devkitc-1  ; or your board name

📖 Usage

Basic Operation

Power On: Connect ESP32-S3 to power via USB
Connect to WiFi:
- Find WiFi network "ESP32-S3-LAB"
- Password: "12345678"
Open Dashboard: Navigate to http://192.168.4.1 in browser
Monitor: View real-time sensor data and system status

Temperature Indicator (LED)

The LED blink pattern changes based on temperature:

COLD (< 20°C): Slow blink (1s on, 1s off)
NORMAL (20-30°C): Medium blink (300ms on, 300ms off)
HOT (30-40°C): Fast blink (120ms on, 120ms off)
CRITICAL (> 40°C): Solid ON (no blinking)

Humidity Indicator (NeoPixel - GPIO 45)

Single pixel color indicates humidity level:

🔵 Blue: DRY (< 40%)
🟢 Green: COMFORT (40-60%)
🟡 Yellow: HUMID (60-80%)
🔴 Red: WET (> 80%)

UI Bar (NeoPixel - GPIO 6)

4-pixel strip with multiple modes:

OFF: All pixels dark
BAR: Visual bar graph of humidity (0-100% = 0-4 LEDs)
DEMO: Rainbow animation
SOS: Emergency SOS pattern
BLINK: Synchronized blinking

Serial Monitoring

Open serial monitor (115200 baud) to see:

Task creation logs
Sensor readings
Semaphore give/take events
TinyML inference results
HTTP request logs

Example output:

[TASK1] ✓ Temp band changed: HOT (32.5°C) → semBandChanged given
[TASK2] ✓ Received semBandChanged (new band: HOT)
[TASK3] ✓ Received semHumChanged (new band: HUMID)
[TASK5] ✓ LCD updated - Values: T=32.5°C H=65.2%
[TinyML] Score 0.045 (T=32.5°C H=65.2%)

📚 API Reference

Global State Structure

struct LiveState {
    // Sensor readings
    float tC;              // Temperature in Celsius
    float rh;              // Relative humidity (%)
    TempBand tBand;        // Current temperature band
    HumBand hBand;         // Current humidity band
    
    // LED state
    uint8_t ledOn;         // LED on/off state (0 or 1)
    uint32_t onMs;         // LED on duration (ms)
    uint32_t offMs;        // LED off duration (ms)
    
    // Semaphore counters
    uint32_t giveTemp;     // semBandChanged given count
    uint32_t takeTemp;     // semBandChanged taken count
    uint32_t giveHum;      // semHumChanged given count
    uint32_t takeHum;      // semHumChanged taken count
    
    // UI control
    uint8_t uiMode;        // NeoPixel UI mode (0-4)
    
    // Task telemetry
    uint32_t dht_last_ms;  // Last DHT read timestamp
    uint32_t led_last_ms;  // Last LED update timestamp
    uint32_t neo_last_ms;  // Last NeoPixel update timestamp
    uint32_t lcd_last_ms;  // Last LCD update timestamp
    uint32_t dht_runs;     // Total DHT task runs
    uint32_t led_runs;     // Total LED task runs
    uint32_t neo_runs;     // Total NeoPixel task runs
    uint32_t lcd_runs;     // Total LCD task runs
    
    // TinyML
    float tinyml_score;    // Anomaly detection score
    uint32_t tinyml_last_ms;
    uint32_t tinyml_runs;
};

Classification Functions

// Classify temperature into band
TempBand classifyTemp(float tC);
// Returns: TempBand::COLD, NORMAL, HOT, or CRITICAL

// Classify humidity into band
HumBand classifyHum(float h);
// Returns: HumBand::DRY, COMFORT, HUMID, or WET

// Convert temperature band to LED blink pattern
void bandToBlink(TempBand b, uint32_t& onMs, uint32_t& offMs);

Task Functions

void task_read_dht20(void* pv);      // Task 1: Sensor reading
void task_led(void* pv);             // Task 2: LED control
void task_neopixel_hum(void* pv);    // Task 3: Humidity indicator
void task_neopixel_ui(void* pv);     // Task 4: UI bar
void task_lcd(void* pv);             // Task 5: LCD display
void tiny_ml_task(void* pvParameters); // Task 6: TinyML inference

📁 Project Structure

MidtermProject_ESP32_PlatformIO/
│
├── platformio.ini              # PlatformIO configuration
├── boards/
│   └── yolo_uno.json          # Custom ESP32-S3 board definition
│
├── include/                    # Public headers (empty - using src/)
│
├── lib/                        # Custom libraries (empty - using dependencies)
│
├── src/                        # Main source code
│   ├── main.cpp               # Application entry point
│   │
│   ├── config/                # Configuration & data structures
│   │   ├── config.h          # Constants, pins, task config
│   │   ├── system_types.h    # Enums, structures, prototypes
│   │   └── system_types.cpp  # Helper implementations
│   │
│   ├── hardware/              # Hardware abstraction layer
│   │   ├── hardware_manager.h
│   │   └── hardware_manager.cpp
│   │
│   ├── tasks/                 # FreeRTOS task implementations
│   │   ├── tasks.h           # Task declarations & documentation
│   │   ├── tasks.cpp         # Task creation
│   │   ├── task1_sensor.cpp  # DHT20 sensor task
│   │   ├── task2_led_neopixel.cpp # LED & NeoPixel tasks
│   │   ├── task3_lcd.cpp     # LCD display task
│   │   └── task5_tinyml.cpp  # TinyML inference task
│   │
│   ├── web/                   # Web server & dashboard
│   │   ├── web_server.h
│   │   ├── web_server.cpp    # HTTP handlers
│   │   └── web_pages.h       # HTML dashboard
│   │
│   └── ml/                    # Machine learning
│       ├── tinyml.h          # TensorFlow Lite includes
│       └── dht_anomaly_model.h # Trained model data
│
├── test/                       # Unit tests (empty)
│
├── data/                       # Project documentation & media
│   ├── Diagram/               # System architecture diagrams
│   │   ├── ExcutionTimeline.png        # Task scheduling timeline
│   │   ├── HardwareWiring.png          # GPIO and I2C connections
│   │   ├── SystemBootSequence.png      # Boot initialization flow
│   │   ├── TaskCommunicationFlow.png   # Semaphore signaling
│   │   ├── WebUserFlow.png             # Web dashboard flow
│   │   ├── README.md                   # Diagram documentation
│   │   └── QUICK_EXPORT_GUIDE.md       # How to generate diagrams
│   │
│   ├── Hardware/              # Hardware photos
│   │   ├── FullSetup.jpg               # Complete system assembly
│   │   ├── Yolo_Uno_ESP32-S3kit.png    # Development board
│   │   ├── DHT20Module.png             # Temperature sensor
│   │   ├── LCD1602Module.png           # Display module
│   │   ├── NeoPixel4LED.png            # LED strip
│   │   ├── Relay.png                   # Relay module
│   │   ├── GPIO.png                    # GPIO pinout
│   │   ├── SensorsAndLCD.jpg           # Sensors assembly
│   │   └── Sensors_Relay_NeoPixelModule.jpg
│   │
│   ├── Dashboard.png          # Main web dashboard screenshot
│   ├── ConfigurationPage.png  # Configuration interface
│   ├── ControlPage.png        # Control panel
│   ├── MainPage.png           # Landing page
│   │
│   ├── Dashboard/             # Dashboard detailed screenshots
│   ├── Configuration/         # Configuration page screens
│   └── Control/               # Control interface screens
│
├── README.md                  # Comprehnesive Instruction for the ProjectProject
│
├── .gitignore                 # Git ignore rules
├── .pio/                      # PlatformIO build artifacts (ignored)
└── .vscode/                   # VS Code settings (ignored)

🤝 Contributing

We welcome contributions! Here's how you can help:

Reporting Bugs

Check existing issues first
Provide detailed reproduction steps
Include serial monitor output
Specify your board and environment

Suggesting Features

Open an issue with [FEATURE] prefix
Describe the use case
Provide implementation ideas if possible

Pull Requests

Fork the repository
Create a feature branch: git checkout -b feature/amazing-feature
Follow existing code style
Add comments and documentation
Test on hardware
Commit: git commit -m 'Add amazing feature'
Push: git push origin feature/amazing-feature
Open a Pull Request

Code Style Guidelines

Use meaningful variable names
Add comments for complex logic
Follow existing indentation (4 spaces)
Document public functions with Doxygen-style comments
Keep functions focused and modular

🔍 Troubleshooting

Common Issues

1. Upload Failed

Problem: Can't upload code to ESP32-S3

Solutions:

Hold BOOT button while connecting USB
Try different USB cable (data cable, not charge-only)
Check driver installation
Press RESET button after upload starts

2. LCD Not Displaying

Problem: LCD backlight on but no text

Solutions:

Verify I2C address (use I2C scanner sketch)
Check SDA/SCL connections (GPIO 11/12)
Adjust LCD contrast potentiometer
Verify 5V power supply to LCD

3. DHT20 Reading NaN

Problem: Temperature/humidity show NaN

Solutions:

Wait 2 seconds after power-on (warm-up time)
Check I2C connections
Verify DHT20 is at 0x38 address
Ensure proper pull-up resistors (if required)

4. NeoPixels Not Working

Problem: NeoPixels don't light up

Solutions:

Verify 5V power supply (NeoPixels need 5V)
Check data pin connections (GPIO 45 and 6)
Add 330Ω resistor on data line
Add 1000µF capacitor across power supply

5. Can't Connect to WiFi

Problem: ESP32-S3-LAB network not visible

Solutions:

Check antenna connection on board
Verify AP is enabled: gWifiMode = "ap"
Look for serial message: "AP IP: 192.168.4.1"
Try power cycle ESP32

6. Web Dashboard Not Loading

Problem: Can connect to WiFi but can't access 192.168.4.1

Solutions:

Disable mobile data on phone
Clear browser cache
Try different browser
Check firewall settings
Verify device got IP: 192.168.4.x

7. Tasks Not Running

Problem: No sensor readings or LED activity

Solutions:

Check serial monitor for task creation messages
Verify semaphores created successfully
Look for stack overflow warnings
Increase task stack sizes in config.h

Debug Serial Commands

Enable verbose logging by modifying serial output in code:

Serial.setDebugOutput(true);

Reset to Factory Settings

To reset all configurations:

Press and hold BOOT button
Press RESET button briefly
Release BOOT button
WiFi settings will reset to defaults

Getting Help

GitHub Issues: Create an issue
Serial Logs: Always include serial monitor output
Hardware Photos: Pictures help diagnose wiring issues

📊 Performance Metrics

Task Execution Times (Approximate)

Task	Execution Time	Stack Usage	Priority
Task 1 (DHT20)	50-100ms	~2KB	3 (High)
Task 2 (LED)	<1ms	~1KB	2
Task 3 (NeoPixel H)	5-10ms	~1KB	2
Task 4 (NeoPixel UI)	10-15ms	~1.5KB	1
Task 5 (LCD)	20-30ms	~1.5KB	1
Task 6 (TinyML)	200-500ms	~6KB	1 (Low)

Memory Usage

Flash (Program): ~850KB / 8MB (10.6%)
SRAM (Runtime): ~180KB / 512KB (35%)
Task Stack Total: ~22KB allocated
TensorFlow Arena: 8KB for ML model

Power Consumption

Idle: ~120mA @ 5V
Active (All tasks): ~180mA @ 5V
Peak (NeoPixels max): ~500mA @ 5V

🎓 Learning Resources

FreeRTOS Concepts

ESP32-S3 Documentation

Sensors & Peripherals

TinyML

TensorFlow Lite Micro
Edge Impulse - Train your own models

📜 License

This project is licensed under the MIT License - see below for details:

MIT License

Copyright (c) 2025 ESP32-S3 Lab

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

🙏 Acknowledgments

Libraries Used

DHT20 by Rob Tillaart - Temperature/humidity sensor driver
Adafruit NeoPixel - WS2812B LED control
LiquidCrystal_I2C by Marco Schwartz - LCD display driver
TensorFlowLite_ESP32 by Tanaka Masayuki - On-device ML inference

Inspiration

FreeRTOS documentation and examples
ESP32 community tutorials
Embedded systems best practices

Contributors

Tran Hoai Nhan - Head Engineer and Manager, Initial development and architecture
Vo Phuc Thien - Assistant Engineer and Maintenance
Community contributors (see GitHub contributors page)

🚀 Future Enhancements

Planned Features

MQTT support for IoT cloud integration
SD card logging for long-term data storage
OTA (Over-The-Air) firmware updates
Mobile app (iOS/Android)
Advanced TinyML models (fire detection, air quality)
BLE support for low-power communication
Multi-sensor support (additional DHT20 units)
Time-series graphing in web dashboard
Alert notifications (email, push)

Known Limitations

Web dashboard uses HTTP (not HTTPS)
Single WiFi client support in AP mode
No persistent storage (settings lost on reboot)
TinyML model is placeholder (needs training)

📞 Contact & Support

GitHub Repository: MidtermProject_ESP32_PlatformIO
Issue Tracker: Report Bugs
Pull Requests: Active PR
Maintainer: leonathn

⭐ Star History

If this project helped you, please consider giving it a ⭐ on GitHub!

Built with ❤️ using ESP32-S3, FreeRTOS, and PlatformIO

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Name		Name	Last commit message	Last commit date
Latest commit History 49 Commits
.platformio		.platformio
.vscode		.vscode
boards		boards
data		data
include		include
lib		lib
node_modules		node_modules
src		src
test		test
.DS_Store		.DS_Store
.gitignore		.gitignore
README.md		README.md
package-lock.json		package-lock.json
package.json		package.json
platformio.ini		platformio.ini

leonathn/MidtermProject_ESP32_FreeRTOSAndWebserver

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ESP32-S3 Multi-Task Environmental Monitoring System

🎯 What Does This System Do?

For End Users

📋 Table of Contents

✨ Features

Core Functionality

Advanced Features

🏗️ System Architecture

Overview

🔧 Hardware Requirements

Essential Components

Specifications

📍 Pin Configuration

GPIO Mapping

Pin Diagram

Hardware Gallery

Complete System Assembly

Hardware Components

System Wiring Diagram

💻 Software Architecture

Module Organization

Key Technologies

📊 System Architecture Diagrams

Task Communication Flow

System Boot Sequence

Task Execution Timeline

🔄 Task Synchronization

Semaphore Flow Diagram

Synchronization Details

Semaphore: semBandChanged

Semaphore: semHumChanged

Semaphore: semLcdUpdate

🎨 Web Dashboard

Access Information

Features

1. Real-Time Monitoring

2. Threshold Configuration

3. NeoPixel UI Control

4. WiFi Configuration

5. GPIO Control

API Endpoints

Web Dashboard Screenshots

Example State Response

🚀 Installation

Prerequisites

Step-by-Step Setup

1. Clone the Repository

2. Open in VS Code

3. Install Dependencies

4. Connect Hardware

5. Build Project

6. Upload to ESP32-S3

7. Verify Installation

⚙️ Configuration

Compile-Time Configuration

Runtime Configuration

Custom Board Configuration

📖 Usage

Basic Operation

Temperature Indicator (LED)

Humidity Indicator (NeoPixel - GPIO 45)

UI Bar (NeoPixel - GPIO 6)

Serial Monitoring

📚 API Reference

Global State Structure

Classification Functions

Task Functions

📁 Project Structure

🤝 Contributing

Reporting Bugs

Suggesting Features

Pull Requests

Code Style Guidelines

🔍 Troubleshooting

Common Issues

Semaphore: `semBandChanged`

Semaphore: `semHumChanged`

Semaphore: `semLcdUpdate`

Packages