Elderly Activity Monitoring System

This project aims to prevent lonely deaths among elderly individuals living alone by providing a privacy-friendly home monitoring solution. Unlike traditional monitoring systems, this approach does not use cameras or wearable devices, ensuring a non-intrusive and respectful solution for elderly care. The system utilizes various sensors to track motion and activity patterns, transmitting data via a home gateway. If prolonged inactivity is detected, a warning message is sent to caregivers via the user interface.

This project is divided into multiple repositories:
[Click Details] -> End-Node, Home-Gateway, Server

 ┌──────────────┐           ┌──────────────────┐           ┌────────────┐           ┌────────┐
 │   End Node   │     →     │   Home Gateway   │     →     │   Server   │     →     │   UI   │
 └──────────────┘           │         │        │           └────────────┘           └────────┘
                   (ZigBee) │         │        │   (MQTT)                (WebSocket)
                            │    MQTT Broker   │
                            └──────────────────┘  

Overview

The Home Gateway connects ZigBee-based sensors to an MQTT broker for real-time IoT data exchange. It receives sensor data through a ZigBee USB module, processes it, and sends structured messages to a central server via the MQTT broker.

Environment

- OS: Ubuntu 24.10 (GNU/Linux 6.11.0-1004-raspi aarch64)  
- Hardware: Raspberry Pi 3B+  
- Python: 3.12.7  
- Python MQTT Library: python3-paho-mqtt 2.0.0-1
- MQTT Broker: Mosquitto 2.0.18  

Architecture & Components

 ┌──────────────┐     ┌─────────────────────┐     ┌────────────────────┐     ┌─────────────────┐     ┌────────────┐
 │   End Node   │  →  │   ZigBee Receiver   │  →  │   MQTT Publisher   │  →  │   MQTT Broker   │  →  │   Server   │ 
 └──────────────┘     └─────────────────────┘     └────────────────────┘     └─────────────────┘     └────────────┘

ZigBee Receiver (Serial Communication)

• ZigBee router MAC addresses must be listed in the .env file, separated by commas
• Configure the ZigBee module as a Coordinator using XCTU and connect it to the hardware via a USB adapter
• Receives data in API 2 Mode (escaped mode)
• Sound, Pressure, and PIR sensors are mapped to specific MAC addresses, rf_value, and sensor names
• Only allowed MAC addresses are processed; data from unlisted MAC addresses is ignored

MQTT Publisher (Paho MQTT)

• Configure the MQTT topic (GATEWAY_ID) in the .env file
• Publishes processed sensor data to an MQTT broker
• Uses 'paho-mqtt' for MQTT communication
• The MQTT topic is automatically derived from 'GATEWAY_ID' by separating the prefix and numeric ID.
• GATEWAY_ID format: {prefix}{id} (e.g., home1, home2, ...)
• MQTT topic format: {prefix}/{id} (e.g., home/1, home/2, ...)
• Converts sensor data into JSON format before publishing:

  {  
      "gateway_id": "home1",                   
      "sensor": "pir",                        
      "value": 1,                        
      "timestamp": "2025-01-23T12:00:00Z"      
  }

• Field Descriptions

  - gateway_id: Identifies the gateway that sent the data  
  - sensor: Type of sensor ('sound', 'pressure', 'pir', etc.)  
  - value: Represents the detected event ('1' means triggered)  
  - timestamp: Time of the event in ISO 8601 format ('YYYY-MM-DDTHH:MM:SSZ') 
  

MQTT Broker (Mosquitto)

• Specify the MQTT broker IP address and port in the .env file
• Manages MQTT message exchange between clients
• Requires authentication (allow_anonymous false)
• Listens on a configurable port (default: 1883)

File Structure

home-gateway/  
│── config/  
│   ├── settings.py           # Loads environment variables and system settings
│── mqtt/  
│   ├── publisher.py          # Publishes sensor data to the MQTT broker 
│── zigbee/  
│   ├── parser.py             # Parses and validates ZigBee frames  
│   ├── receiver.py           # Reads ZigBee data from the serial Port  
│── main.py  
│── mqtt-broker.sh            # Script to install and configure the Mosquitto MQTT broker  
└── setup.sh                  # Setup script for dependencies and environment configuration  

Setup & Installation

1. Install Dependencies

Run the setup script to install all necessary dependencies:

chmod +x setup.sh
./setup.sh

This will install python3-paho-mqtt, detect the ZigBee USB module at /dev/ttyUSB, and ensure the user belongs to the dialout group for serial access.

2. Configure the Environment

Modify the .env file to set the appropriate values for ZigBee and MQTT.

3. Install & Configure the MQTT Broker

Run the MQTT broker setup script:

chmod +x mqtt-broker.sh
./mqtt-broker.sh

This will install Mosquitto, set up authentication and listener port, and enable automatic startup on boot.

4. How to Run

Once the setup and configuration are complete, you can start the Home Gateway by running:

python3 main.py

This will initialize the ZigBee receiver, process and filter sensor data based on registered MAC addresses, and publish structured messages to the configured MQTT broker.

Verifying MQTT Messages

To check if the gateway is publishing messages correctly, subscribe to the relevant MQTT topic:

mosquitto_sub -h <MQTT_BROKER_IP> -t "<prefix>/<id>" -u <username> -P <password> -v

To run the script in the background:

nohup python3 main.py > logs.txt 2>&1 &

To stop the service:

ps aux | grep main.py
kill <PID>