Witmotion Vibration Analysis

This project implements real-time vibration analysis using data from Witmotion Bluetooth devices. The analysis is performed using Fast Fourier Transform (FFT) on the time series data received from the device.

Setup

1. Create and activate virtual environment:

python3 -m venv venv
source venv/bin/activate  # On Linux/Mac

2. Install dependencies:

pip install -r requirements.txt

3. Pair WitMotion device through Bluetooth at least once

   • Open bluetooth, go to settings
   • When the scan shows HC-06 or something similar, connect to it
   • Input the pairing code "1234"
   • HC-06 will show connected once, but disconnected quickly afterward, just make sure it shows paired, will be fine for using it as serial device /dev/rfcomm*

   For more information about the Witmotion device, visit: Witmotion WT901BLECL 9-axis BLE Accelerometer

Project Structure

• src/: Source code directory
• tests/: Test files directory
• requirements.txt: Python package dependencies

Usage

python src/main.py

Configuration Parameters

The following parameters can be configured in src/main.py:

Device Configuration

• SERIAL_DEVICE: Path to the serial device for the HC-06 module
  • Default: "/dev/rfcomm0"
  • Example: "/dev/rfcomm1" if using two modules, check after pairing
  • Note: The device must be paired via Bluetooth first

Data Collection

• SAMPLING_RATE: FFT sample rate in Hz

  • Default: 10.0 Hz
  • Should match the actual sampling rate of the Witmotion device
  • Witmotion specification shows it's configurable from 0.2Hz to 200Hz, default is 10Hz

• COLLECTION_DURATION: Duration of data collection in seconds

  • Default: 120.0 seconds
  • Longer durations provide more data points for analysis
  • Affects the time-domain resolution of the FFT
  • Consider memory usage for very long durations

Output

The analysis results include:

• Time-domain plots for acceleration and gyroscope data
• Frequency-domain plots showing the FFT analysis
• Dominant frequencies for each axis (X, Y, Z)
• Magnitude of each dominant frequency

Notes

• The device must be paired via Bluetooth before running the program
• The HC-06 module typically appears as /dev/rfcomm0 after pairing
• The program will automatically create a 'plots' directory for saving visualizations
• Both acceleration and gyroscope data are collected simultaneously for better time synchronization