LEMION WEATHER STATION // TECHNICAL HANDOVER SPECIFICATION

1. EXECUTIVE SUMMARY & SYSTEM ARCHITECTURE

The Lemion Weather Station is an end-to-end IoT monitoring solution designed to collect ambient environmental parameters (Temperature, Humidity, Barometric Pressure) using an ESP32 hardware microcontroller and BMP280 sensor module, transmit measurements securely over HTTPS REST APIs to a MySQL database, and present real-time/historical telemetry via a futuristic Sci-Fi Web Dashboard featuring interactive 3D Obsidian node graphs and browser-based Web Serial firmware flashing.

2. SERVER & DEPLOYMENT SPECIFICATIONS

A. Directory & File Structure

/home/u639131817/domains/108ido.com/public_html/lemion/
├── index.html                  # Main Web HUD Dashboard (HTML5)
├── style.css                   # Sci-Fi HUD Design Tokens & 3D Styling (CSS3)
├── app.js                      # Application Engine, High-Contrast ApexCharts & Three.js (JS ES6)
├── manifest.json               # ESP Web Tools Web Flasher Manifest
├── firmware.bin                # Compiled ESP32 Firmware Binary (For Web Flashing)
├── project_handover.html       # Full Technical Handover Documentation
└── api/
    ├── config.php              # Global Database & API Auth Credentials (Asia/Bangkok GMT+7)
    ├── db.php                  # PDO MySQL Connection Singleton (SET time_zone = '+07:00')
    ├── upload.php              # Ingestion Endpoint for ESP32 POST Data (GMT+7 Timestamps)
    ├── latest.php              # Endpoint returning most recent telemetry reading
    ├── history.php             # Endpoint for range queries & specific date filtering
    ├── seed.php                # Database Seeder (Generates realistic history)
    └── setup.php               # Database Schema Initializer (Creates table)
            

B. How to Deploy Updates

1. Option 1 (Hostinger CLI / API): Use the Hostinger API static deployment tool by compressing files into a ZIP archive and calling hosting_deployStaticWebsite.
2. Option 2 (FTP / SFTP Upload): Connect via FTP to 108ido.com port 21 using Hostinger cPanel FTP credentials and upload all files into public_html/lemion/.
3. Browser Cache Invalidation: Whenever updating index.html, increment the version query parameter (e.g. app.js?v=20260725_v8) to ensure clients bypass local caching.

3. DATABASE CREDENTIALS & SCHEMA SPECIFICATION

Table Schema: lemion_weather

CREATE TABLE IF NOT EXISTS `lemion_weather` (
  `id` INT AUTO_INCREMENT PRIMARY KEY,
  `temperature` FLOAT NOT NULL,
  `humidity` FLOAT NOT NULL,
  `pressure` FLOAT NOT NULL,
  `created_at` DATETIME DEFAULT CURRENT_TIMESTAMP,
  INDEX `idx_created_at` (`created_at`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
            

4. REST API ENDPOINTS SPECIFICATION

1. Data Ingestion Endpoint: POST /api/upload.php

Called by ESP32 microcontroller every 60 seconds to upload sensor readings.

Request Headers: Content-Type: application/json

// Request Body JSON Payload
{
  "api_key": "lemion-secret-api-key-2026",
  "temperature": 28.5,
  "humidity": 65.0,
  "pressure": 1009.4
}
            

2. Latest Reading Endpoint: GET /api/latest.php

// Response JSON (Times returned in Asia/Bangkok GMT+7)
{
  "status": "success",
  "data": {
    "id": 2639,
    "temperature": 27.2,
    "humidity": 69.0,
    "pressure": 1013.4,
    "created_at": "2026-07-25 18:42:07"
  }
}
            

3. History & Date Query Endpoint: GET /api/history.php

• range=7d|30d|all - Returns telemetry records within the requested relative range.
• date=YYYY-MM-DD - Returns all 24-hour records for a specific date along with daily summary averages.

5. ESP32 FIRMWARE & COMPILATION GUIDE

The microcontroller source file is located at c:\esp32\esp32_weather.ino (or c:\esp32\esp32_weather\esp32_weather.ino).

Hardware Wiring (Shared I2C Bus on GPIO 21 / 22)

How to Compile .ino into firmware.bin

# Using arduino-cli (Command Line):
arduino-cli compile --fqbn esp32:esp32:esp32 "c:\esp32\esp32_weather" --output-dir "c:\esp32\build"

# Using Arduino IDE 2.x:
1. Open esp32_weather.ino in Arduino IDE.
2. Select Board: Tools -> Board -> ESP32 Arduino -> ESP32 Dev Module.
3. Click Sketch -> Export Compiled Binary (Ctrl + Alt + S).
            

6. BROWSER-BASED WEB FIRMWARE FLASHER (WEB SERIAL API)

The dashboard incorporates ESP Web Tools to allow technicians to flash updated ESP32 firmware directly over a USB cable inside Google Chrome or Microsoft Edge without taking the board out of its enclosure or installing local compilers.

1. Connect the ESP32 board to the computer USB port using a data-capable USB cable.
2. Open https://lemion.108ido.com in Chrome or Edge.
3. Click the top bar button: WEB FIRMWARE FLASHER.
4. Click CONNECT & FLASH FIRMWARE in the popup modal.
5. Select the COM Port corresponding to your ESP32 (e.g. CP2102 on COM5) and click Connect -> Install.

7. HOSTING LIMITATIONS & HIGH-FREQUENCY INGESTION ANALYSIS (5-SECOND INTERVAL)

Can the ESP32 microcontroller send data to the backend database every 5 seconds? Technically, the ESP32 code can be set to sendInterval = 5000;. However, doing HTTPS POST requests directly to MySQL every 5 seconds on shared web hosting (Hostinger) introduces severe operational limitations and architectural bottlenecks.

A. Data Volume & Database Growth Comparison

B. Key Bottlenecks & Hostinger Shared Hosting Limits

8. PHYSICAL ROTARY SELECTOR SWITCH IMPLEMENTATION GUIDE (DISPLAY TOGGLING)

To enable the front panel Rotary Selector Switch on the enclosure box to switch LCD 1602 display screens (e.g. turning Left displays Temp/Humidity, turning Right displays Pressure/Wi-Fi Status), follow this implementation specification:

A. Hardware Connection Diagram

• Switch Common Terminal (COM): Wire to ESP32 GND.
• Position 1 Contact (Turn Left): Wire to ESP32 GPIO 13.
• Position 2 Contact (Turn Right): Wire to ESP32 GPIO 14.

B. Recommended C++ Firmware Architecture

// Define Pin Assignment for Rotary Switch
#define SWITCH_PIN_LEFT  13
#define SWITCH_PIN_RIGHT 14

void setup() {
    pinMode(SWITCH_PIN_LEFT, INPUT_PULLUP);
    pinMode(SWITCH_PIN_RIGHT, INPUT_PULLUP);
}

void updateLCDDisplay() {
    bool isLeftPressed  = (digitalRead(SWITCH_PIN_LEFT) == LOW);
    bool isRightPressed = (digitalRead(SWITCH_PIN_RIGHT) == LOW);

    lcd.clear();
    if (isLeftPressed) {
        // Mode 1: Display Temperature & Humidity
        lcd.setCursor(0, 0);
        lcd.print("TEMP: "); lcd.print(tempC, 1); lcd.print(" C");
        lcd.setCursor(0, 1);
        lcd.print("HUM : "); lcd.print(humidity, 1); lcd.print(" %");
    } else if (isRightPressed) {
        // Mode 2: Display Barometric Pressure & System Status
        lcd.setCursor(0, 0);
        lcd.print("PRES: "); lcd.print(pressure, 1); lcd.print("hPa");
        lcd.setCursor(0, 1);
        lcd.print("SYS : ONLINE/WiFi");
    } else {
        // Default Mode: Auto-cycle or Summary
        lcd.setCursor(0, 0);
        lcd.print("LEMION SYS READY");
        lcd.setCursor(0, 1);
        lcd.print("SELECT MODE...  ");
    }
}
            

9. OVER-THE-AIR (OTA) WI-FI FIRMWARE FLASHING SPECIFICATION

To eliminate the need to plug in a USB cable when updating ESP32 firmware in the future, integrate ArduinoOTA or AsyncElegantOTA into the C++ codebase:

C++ Code Integration Example (`ArduinoOTA`)

#include <WiFi.h>
#include <ArduinoOTA.h>

void setupOTA() {
    ArduinoOTA.setHostname("lemion-weather-station");
    ArduinoOTA.setPassword("lemion-ota-pass-2026");

    ArduinoOTA.onStart([]() { Serial.println("Start OTA Updating..."); });
    ArduinoOTA.onEnd([]()   { Serial.println("\nEnd OTA Update."); });
    ArduinoOTA.onProgress([](unsigned int progress, unsigned int total) {
        Serial.printf("Progress: %u%%\r", (progress / (total / 100)));
    });

    ArduinoOTA.begin();
}

void loop() {
    ArduinoOTA.handle(); // Must be called frequently in loop()
    // ... rest of sensor reading and sending code ...
}
            

10. RECENT IMPROVEMENTS & HANDOVER CHECKLIST

• ✅ Timezone Sync (GMT+7): Configured PHP date_default_timezone_set('Asia/Bangkok') and MySQL SET time_zone = '+07:00' to resolve the 7-hour offset issue.
• ✅ High-Contrast ApexCharts Styling: Upgraded chart lines to stroke width 3.5px with bright neon glowing colors (#ffaa00, #00ffaa, #00e5ff) and enhanced dropShadow glow.
• ✅ Verified Direct USB Flashing: Tested and verified direct USB flashing on COM5 via arduino-cli upload.
• ✅ Complete Handover ZIP Package: Compressed all project files into lemion_project_handover_full.zip ready for Lemion team transfer.