Simple sensor data station

A Python implementation of a system that simply collects and shows measurement BLE broadcasts it has received from any nearby RuuviTag sensors, and possibly others in future versions. The web interface is served on a local address.

The data is stored into a local SQLite database ./readings.db. The frontend is written in plain CSS/JS with everything statically included, which means there is no need to compile or install dependencies.

The script runs concurrently the following subcomponents:

• RuuviTag scanner scanning sensor data using Bluetooth
• AIOHTTP web server serving a page to view the sensor data

This version has been tested on macOS (Macbook Air M1) and Raspberry Pi OS (Raspberry Pi Zero W 2).

Web interface

The responsive interface should adapt to majority of devices and screen configurations.

Features

• Automatically pick up detected tags and show the measurements
• Automatically recover if server is temporarily unreachable
• Data is refreshed in 5 second intervals
• Time is shown relative to current time ("X ago" format)
• Window/tab title also shows the temperature
• Sensor stays selected over reloads (only selected MAC stored in sessionStorage)
• Sensors can be named (max 255 characters)

Installation

Initialize venv (Python virtual environment) in the directory:

# On some systems the command starts "python3"
python -m venv .venv

Activate virtual environment and install dependencies from requirements.txt:

source .venv/bin/activate
pip install -r requirements.txt

Run the system:

./main.py

The script creates the database file (unless it exists), and starts listening to BLE broadcasts until it is shut down.

Once running, the web interface can be seen at http://localhost:8080, or with local IP http://<local-ip>:8080.

Self-hosted frontend resources

Some frontend resources have been statically included to simplify installation and dependency management.

• Fontsource Fonts:
  https://fontsource.org/fonts/oswald
• Bootstrap Icons:
  https://icons.getbootstrap.com
• Day.js – relative time format ("X ago"):
  https://day.js.org/en/

Future developments

• Add chart graphics to visualize trends (sparkline)
• Add an API for receiving sensor data over the web
• Add support for other sensors as well (for example, Raspberry Pi Pico)
• Add threshold levels that trigger given actions (for example, min/max level that changes text to red)
• Localizations, Fahrenheit

Licence

MIT