liblsl (C++) and PyLSL doesn't seem to receive EEG LSL packets correctly on Debian Linux (testing)

[cslr]

The following python test program doesn't show EEG signals correctly and similar problems are in liblsl (C++) compiled on Linux. BrainAccessBoard (BrainAccess HALO EEG) is run on Windows and LSL is sent to local wifi network. On the original Windows machine LSL is shown correctly by third party application.

New Debian Linux (testing) laptop receives LSL stream but when PyLSL is run or liblsl is used, it doesn't show EEG signals correctly at all when plotted.

Python code:

#!/usr/bin/python3

import matplotlib.pyplot as plt
import numpy as np

from pylsl import resolve_streams, StreamInlet
import sys


streams = resolve_streams()

for stream in streams:
    print(f"Name: {stream.name()}, Type: {stream.type()}")

if(len(streams) <= 0):
    sys.exit("No LSL stream");

inlet = StreamInlet(streams[0])

data = []
timestamps = []

for _ in range(1000): # 250 Hz output rate means 4 secs of data???
    sample, timestamp = inlet.pull_sample()
    data.append(sample)
    timestamps.append(timestamp)

data = np.array(data)
# plt.plot(timestamps)
plt.plot(timestamps, data)
plt.xlabel("Time (s)")
plt.ylabel("EEG Amplitude")
plt.title("EEG Signal")
plt.show()

[zeyus]

@cslr Could this be a network setup issue? You mentioned that it works from the original Windows machine, but that will be using the local / loopback interface so it wouldn't go through the router or wifi. Is the windows computer wired to the LAN or is it also wifi? Either way, routers will often drop multicast / broadcast / UDP, especially across LAN <-> WLAN, or VLAN <-> VLAN boundaries.

You may have sorted this issue by now, but one thing you can do if you have a case like this, is manually specify the IP addresses in the LSL API config, then you can see if it is a discovery problem (UDP / multicast), or an actual problem with the data processing.