Smart Climate Controller System (RTOS-Based)

This project implements a real-time climate control system on an ESP32-S3 (YoloUNO) development board using a cooperative scheduler and FreeRTOS. The system reads temperature and humidity from a DHT21 sensor and uses threshold-based logic to control a heater, cooler, and humidifier, with LED indicators for each state.

🧠 Key Features

• 🔁 Real-Time Scheduling: Custom cooperative scheduler with 1 ms tick resolution driven by FreeRTOS.
• 🌡️ Sensor Integration: Periodic readings from a DHT21 sensor (every 5 seconds).
• 🔥 Actuator Control:
  • Heater: Red/Orange/Green LED based on temperature thresholds.
  • Cooler: Turns on when too hot; turns off automatically after 5 seconds.
  • Humidifier: Runs a 3-phase FSM (Green → Yellow → Red) when humidity is too low.
• 💡 Heartbeat: On-board LED blinks every second to indicate system health.
• 🧱 Modular Code Structure: Separate modules for sensor reading, logic control, device drivers, and RTOS tasks.

🛠️ Hardware Requirements

• ESP32-S3 (YoloUNO or equivalent)
• DHT21 Sensor
• Bi-color LEDs for heater, cooler, humidifier (2 pins each)
• On-board LED (for heartbeat)

Wiring Example:

Component	GPIO Pins
DHT21	A2 (Data), 3.3V, GND
Heater LED	D6 & D7
Cooler LED	D8 & D9
Humidifier LED	D10 & D17
Heartbeat LED	D48

📁 Project Structure

project_climate/
├── src/
│ ├── main.ino # Main entrypoint
│ ├── scheduler/ # Custom scheduler
│ ├── platform/ # RTOS timer & heartbeat
│ ├── sensors/ # DHT21 sensor module
│ ├── control/ # LightControl logic
│ ├── devices/ # Heater, Cooler, Humidifier drivers
│ ├── tasks/ # Named task files
│ └── config.h # Pin mappings & thresholds
├── docs/ # Block diagram, FSM, timing chart
├── .gitignore
└── README.md

🚀 How It Works

1. task_ReadSensors() is scheduled every 5000 ms to read temperature and humidity.
2. Readings are passed to LightControl_Update(), which decides:
   • Heater color (RED, ORANGE, GREEN)
   • Whether to activate the cooler for 5 seconds
   • Whether to start the humidifier FSM
3. The vTimerTask (FreeRTOS) updates the scheduler every 1 ms and toggles the system heartbeat LED every second.
4. The scheduler calls SCH_Dispatch_Tasks() from the main loop to execute due tasks.

📷 Diagrams

• 🧩 System Block Diagram
• 🔄 Humidifier State Machine
• 📉 Task Timing Diagram

💻 Development Environment

• Arduino IDE
• DHT sensor library by Adafruit
• FreeRTOS support for ESP32 (bundled with ESP32 board core)