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@@ -10,12 +10,95 @@ This project implements a real-time temperature and humidity monitoring system u
 
 ## 🧠 System Architecture
 
+The system is designed using a **layered architecture**, where each component has a specific responsibility. This separation improves maintainability and clarity.
+
+---
+
+### 🔹 1. Hardware Layer (Sensor)
+
+The **HTU21D sensor** measures temperature and humidity and communicates using the **I2C protocol**.
+
+* The Raspberry Pi acts as the **master**
+* The sensor acts as the **slave**
+* Data is transmitted over SDA (data) and SCL (clock)
+
+---
+
+### 🔹 2. Data Acquisition Layer (C Program)
+
+A program written in C interacts directly with the I2C interface:
+
+* Opens the I2C device (`/dev/i2c-1`)
+* Sends commands to the sensor
+* Reads raw data
+* Converts it into human-readable values (°C and %)
+
+👉 Output is formatted as a JSON file:
+
+```json
+{ "temperature": 23.9, "humidity": 57.4 }
 ```
-HTU21D Sensor → I2C → C Program → JSON File → Nginx → Web Browser
+
+---
+
+### 🔹 3. Data Persistence Layer (JSON File)
+
+The JSON file acts as an **intermediate data layer**:
+
+* Stores the latest sensor reading
+* Decouples backend (C) from frontend (JavaScript)
+* Enables simple data exchange without a database
+
+---
+
+### 🔹 4. Web Server Layer (Nginx)
+
+Nginx serves static files:
+
+* HTML (interface)
+* JavaScript (logic)
+* JSON (sensor data)
+
+👉 It acts as the **bridge between the system and the user’s browser**
+
+---
+
+### 🔹 5. Presentation Layer (Frontend)
+
+The browser executes JavaScript:
+
+* Uses `fetch()` to request the JSON file
+* Updates the DOM dynamically
+* Displays values in real time
+
+---
+
+### 🔄 Data Flow Summary
+
+```text
+Sensor → I2C → C Program → JSON → Nginx → Browser → User Interface
 ```
 
 ---
 
+### 🧠 Key Design Decisions
+
+* **Use of JSON:** lightweight and easy to parse
+* **Polling (setInterval):** simple real-time updates
+* **Separation of layers:** avoids tight coupling between components
+
+---
+
+### ⚙️ Why This Architecture Works
+
+* Modular → each part can be modified independently
+* Scalable → can add database or APIs later
+* Simple → ideal for embedded + web integration
+
+---
+
+---
+
 ## 🧰 Materials
 
 ### 🔧 Hardware