Team Members: Akhil Kumar Puri, Abhinav Rao Veeramalla

🧊 Cold Chain IoT Monitoring System

An end-to-end IoT solution for real-time monitoring of temperature-sensitive goods such as vaccines, food, or pharmaceuticals. This system uses an ESP32 microcontroller, various sensors, MQTT for secure cloud transmission, InfluxDB for time-series data storage, and Grafana for real-time visualization.

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📦 Project Structure

│
├── bridge_script/
│ └── mqtt_to_influxdb.py # Python script to receive MQTT and write to InfluxDB
│
├── cold_chain_sensor_copy_20250508220111/
│ └── cold_chain_sensor_copy_20250508220111.ino # Arduino sketch for ESP32
│
├── dashboard/
│ └── Cold Chain Monitoring-1746755953723.json # Grafana dashboard export
│
├── mqtt_publisher/
│ ├── influxdb_config.env # InfluxDB connection configuration
│ └── mqtt_publisher.py # Script to publish MQTT messages (testing/simulation)
│
├── simulated_data/
│ └── generate_simulated_data.py # Script to generate test sensor data
│
├── telegraf.conf # Telegraf config for MQTT-to-InfluxDB pipeline
├── README.md # This file

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## 📡 Hardware Used

| Component | Description |
|----------|-------------|
| ESP32 Dev Board | Central IoT controller |
| DHT11 Sensor | Temperature and humidity sensing |
| LDR (Digital) | Detects light exposure indicating container opening |
| GPS Module (NEO-6M) | Captures latitude and longitude of the shipment |

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## 🔁 Data Workflow

1. ESP32 collects sensor data every 2.5 seconds
2. Data is structured into JSON:
```json
{
  "temperature": 24.5,
  "humidity": 68,
  "light": 1,
  "latitude": 40.7128,
  "longitude": -74.0060,
  "timestamp": 1746499505
}

3. Sent via MQTT over TLS to HiveMQ Cloud
4. Python script subscribes to MQTT topic and inserts data into InfluxDB
5. Grafana visualizes real-time environmental data

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🛠️ Software Stack

Layer	Tools/Tech
Microcontroller	ESP32 + Arduino IDE
Messaging	MQTT (HiveMQ Cloud Broker)
Cloud & Storage	InfluxDB (local or cloud)
Visualization	Grafana
Backend Script	Python + Paho MQTT Client
Optional	Telegraf (MQTT to InfluxDB bridge)

🚀 Getting Started

ESP32 Code

• Upload cold_chain_sensor_copy_20250508220111.ino to your ESP32 via Arduino IDE
• Ensure libraries:
  • DHT, TinyGPSPlus, WiFi, PubSubClient

Python MQTT Subscriber

pip install paho-mqtt influxdb
python mqtt_influx_connection.py

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🔐 MQTT Broker Setup

• Broker: HiveMQ Cloud
• Port: 8883
• Use TLS connection with username and password authentication
• Topic: cold_chain_data

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📽️ Project Video

▶️ Unlisted YouTube Demo: Watch the presentation

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👥 Contributors

• [Akhil Kumar Puri] – Sensor Integration & Microcontroller Code, Presentation
• [Abhinav Rao Veeramalla] – Cloud Integration, Python & Grafana, Testing, Debugging,