UD18 BLE Data Logger and Visualization

This project provides a real-time data logger and visualizer for UD18 BLE devices. Using Python, BLE communication, and Streamlit, the app logs voltage, current, power, and D+/D- values, stores the data in a CSV file, and visualizes live metrics with interactive plots.

Figure 1: UD18 BLE Device

Features

• Real-Time BLE Data Logging
  Collects data from UD18 BLE devices every few seconds.

• Dynamic Visualizations
  Interactive Plotly graphs for power, voltage, current, and D+/D- measurements.

• Dual Data View
  Simultaneously visualize data with dynamic plots and access raw data in a table format.

• User-Friendly Control Panel
  Start or stop logging with a single click in the app interface.

• Instant Metrics
  Displays real-time Voltage, Current, Power, and D+/D- values in intuitive metric boxes.

How It Works

1. Data Logging

   • The ud18Logger.py script uses the bleak library to collect data from the UD18 BLE device.
   • Logs are saved in real-time to ble_data_log.csv.

2. Live Visualization

   • The Streamlit app (ud18_streamlit_app.py) reads the data, updates key metrics, and renders live visualizations.

3. User Interaction

   • Users can control logging, view metrics, and switch between plots and the raw data table.

Figure 2: Streamlit App Interface

Project Structure

📁 UD18-BLE-Logger/
│
├── ud18_streamlit_app.py - Streamlit app for visualization and control
├── ud18Logger.py - BLE data logger script
├── ble_data_log.csv - CSV file storing logged data (auto-generated)
├── README.md - Project documentation
└── requirements.txt - Python dependencies

Installation

Prerequisites

• Python 3.8 or higher
• BLE-compatible system (Bluetooth Low Energy support is required).

Install Dependencies

Run the following command:
pip install -r requirements.txt

How to Run

Start the Logger

To start logging data, run:
python ud18Logger.py

Run the Visualization App

Launch the Streamlit app using:
streamlit run app.py

Open the app in your browser at http://localhost:8501.

Live Data Visualization

Tab 1: Control Panel and Visualizations

• Real-time plots for:
  • Voltage (V)
  • Current (A)
  • Power (W)
  • D+ and D- Voltages (dual-line plot).

Tab 2: Raw Data Table

• Displays logged data in a tabular format directly from ble_data_log.csv.

Key Libraries

• Streamlit - Web-based interface for Python apps.
• Plotly - Interactive plotting and visualizations.
• Bleak - Bluetooth Low Energy communication.
• Pandas - Data manipulation and CSV handling.

Notes

• Data is saved to ble_data_log.csv automatically during logging.
• The CSV is cleared at the start of each logging session to prevent data overflow.
• Modify logging intervals by editing LOG_INTERVAL_SECONDS in ud18Logger.py.

Future Enhancements

• Alert System: Notify users when metrics exceed thresholds.
• Historical Data Analysis: Load and visualize past CSV files.
• Multi-Device Support: Log data from multiple UD18 devices simultaneously.

Contributing

Contributions are welcome! Please feel free to submit issues or pull requests.

License

This project is licensed under the MIT License.

Contact

For questions or support, please contact:
Martin Kaiser
martinkaiser.bln@gmail.com