ChillControl

Smart IoT Monitor for Coolers and Refrigerators

ChillControl is an ESP32-based IoT solution designed to monitor the efficiency and usage of both portable coolers and standard refrigerators. It tracks temperature, humidity, and door activity while calculating real-time energy loss and financial costs associated with door openings in refrigerator mode.

Features

• Dual Mode Operation: Toggle between Cooler and Refrigerator modes via Adafruit IO.
• Energy & Cost Tracking: In Refrigerator mode, the device calculates energy loss (Wh) and estimated cost (€) based on air exchange physics.
• Offline Resilience: Uses ESP32 Preferences to save settings (temperature limits and mode) to non-volatile memory. Settings are remembered even after power loss.
• Smart Connectivity: * Automatically detects network loss and switches to OFFLINE MODE without freezing the local logic.
  • Visual "YHTEYS PALAUTETTU" (Connection Restored) notification when returning to WiFi range.
• Local Interface: 16x2 I2C LCD provides real-time stats including door open counts and total open duration.
• Integrated Alarm: Active buzzer alerts if the temperature exceeds the user-defined limit or if the door remains open for more than 10 seconds.

Hardware Requirements

• Microcontroller: ESP32 (e.g., DevKit V1)
• Sensor 1: DHT11 or DHT22 (Temperature & Humidity)
• Sensor 2: Hall Effect Sensor or Magnetic Reed Switch (Door Detection)
• Display: I2C LCD 1602
• Alert: Active Buzzer
• Power: USB or Battery Pack

Pin Configuration

Component	ESP32 Pin
DHT11 Data	GPIO 27
Hall Sensor	GPIO 14
Buzzer	GPIO 13
I2C SDA	GPIO 21
I2C SCL	GPIO 22

Installation & Setup

1. Adafruit IO Setup

Create a dashboard with the following feeds:

• lampotila (Temperature)
• kosteus (Humidity)
• oven-avausmat (Door open count)
• aukioloaika (Total open duration)
• hukka-energia (Energy loss Wh)
• hukka-eurot (Cost in €)
• lampotilaraja (Temperature limit - Slider)
• laitemoodi (Mode - Toggle: 0=Fridge, 1=Cooler)

2. Software Setup

1. Install the following libraries in Arduino IDE:
   • Adafruit MQTT Library
   • DHT sensor library
   • LiquidCrystal I2C
2. Update the ssid, password, AIO_USERNAME, and AIO_KEY in the source code.
3. Upload the code to your ESP32.

Logic Overview

The device uses a non-blocking MQTT connection logic. This ensures that even if the WiFi signal is blocked by a thick refrigerator door or lost during travel, the local door-monitoring and alarm logic continue to function perfectly.

To ensure data integrity, all statistics (counts, duration, and energy costs) are automatically reset when the user switches between Cooler and Refrigerator modes via the Adafruit IO dashboard.

---

Developed as a smart solution for better energy awareness and cold chain monitoring.