DataHub

DataHub

Developer(s)	Christian Kothe; Chadwick Boulay.
Development status	-in development-
Written in	C, C++, Python, Java, C#, MATLAB
Operating system	Windows, Linux, MacOS, Android, iOS
Type	Data collection
License	Open source
Website	LSL webpage
Manuals Documentation LSL Validation Supported Devices and Tools

The DataHub Makes use of the lab streaming layer. The lab streaming layer (LSL) is a system for the unified collection of measurement time series in research experiments that handles both the networking, time-synchronization, (near-) real-time access as well as optionally the centralized collection, viewing and disk recording of the data.

Installation

Our support for LSL is mainly done in python. Download python here: Please choose a 64 bit version.. Run the installer and make sure to add Python to the file path (it's an option in the installer). Open a command prompt, start with upgrading the pip installer by typing:
c:>python -m pip install --upgrade pip
Then:
c:>pip install pylsl

more info: cross platform pylsl

Versions

The TSG uses the version 1.15.0. Open a command and type the following to find the version used:

c:>python
>>> import pylsl
>>> print(pylsl.__version__)

Usage

Python

A short example for sending lsl streaming data:

 1#!/usr/bin/env python
 2
 3import threading
 4from pylsl import StreamInfo, StreamOutlet
 5
 6def getData():
 7    while running:
 8        buffer_in = getSensorData()
 9        send_data = True
10        time.sleep(0.001)
11
12info = StreamInfo(
13    name='MyStream', 
14    type='COP', 
15    channel_count=4, 
16    nominal_srate = 200, 
17    source_id='BalanceBoard_stream'
18    )
19outlet = StreamOutlet(info) 
20
21threading.Thread(target=getData).start()
22while running == True:
23	if send_data:
24		outlet.push_chunk(buffer_in)
25		send_data = False

A short example for receiving lsl data:

 1#!/usr/bin/env python
 2
 3from pylsl import StreamInlet, resolve_stream
 4
 5streams = resolve_stream('name', 'MyStream')
 6#streams = resolve_streams()
 7
 8inlet = StreamInlet(streams[0])
 9while True:
10    sample, timestamp = inlet.pull_sample()
11    print(timestamp, sample)

Matlab

Please, read the instructions on the GitHub labstreaminglayer website (https://github.com/labstreaminglayer/liblsl-Matlab) on how to prepare Matlab to work with LSL. You can either use the latest release for your Matlab version, or if that doesn't workout well, build it from the source files. Make sure to add the liblsl-Matlab folder to your path recursively to make it available to your own scripts.

A short example for sending lsl streaming data:

 1%% instantiate the library
 2disp('Loading library...');
 3lib = lsl_loadlib();
 4
 5% make a new stream outlet
 6disp('Creating a new streaminfo...');
 7info = lsl_streaminfo(lib,'BioSemi','EEG',8,100,'cf_float32','sdfwerr32432');
 8
 9disp('Opening an outlet...');
10outlet = lsl_outlet(info);
11
12% send data into the outlet, sample by sample
13disp('Now transmitting data...');
14while true
15    outlet.push_sample(randn(8,1));
16    pause(0.01);
17end

A short example for receiving lsl streaming data:

 1%% instantiate the library
 2disp('Loading the library...');
 3lib = lsl_loadlib();
 4
 5% resolve a stream...
 6disp('Resolving an EEG stream...');
 7result = {};
 8while isempty(result)
 9    result = lsl_resolve_byprop(lib,'type','EEG'); end
10
11% create a new inlet
12disp('Opening an inlet...');
13inlet = lsl_inlet(result{1});
14
15disp('Now receiving data...');
16while true
17    % get data from the inlet
18    [vec,ts] = inlet.pull_sample();
19    % and display it
20    fprintf('%.2f\t',vec);
21    fprintf('%.5f\n',ts);
22end