OpenBCI GUI FFT LSL Hangup

Comments

• wjcroft Mount Shasta, CA

  February 2020

  Mentioning Richard @retiutut, who is the GUI developer / enhancer. Very soon the GUI will be streamlined by dropping the separate 'Hub' process. Instead using the new Brainflow libraries. Brainflow also supports Python and many other languages.

  https://brainflow.readthedocs.io/en/stable/

  Additionally, it is not hard to invoke DSP functions from Python libraries. Thus you could do your own FFT.

  https://www.google.com/search?q=python+dsp+library

  Regards, William
• wjcroft Mount Shasta, CA

  February 2020

  @jstieger, can you mention your computer setup there, OS, hardware, year, etc.? Have you tried this on other machines? Richard tells me he has had multiple streams going with no issues.
• retiutut Louisiana, USA

  February 2020

  Please post the full Python code (as text) you are using so that this can be replicated by others.
• jstieger Carnegie Mellon University

  February 2020 edited February 2020

  Thanks for the comments!
  Unfortunately I only own one machine, so I need to make the code work on my laptop.

  System:
  Mac OSMojave 10.14
  MacBook Pro (Retina, 15-inch, Mid 2014)
  Processor: 2.5 GHz Intel Core i7
  memory: 16 GB 1600 MHz DDR3
  Graphics: NVIDIA GeForce GT 750M 2048 MB
  Intel Iris Pro 1536 MB

  Code:
  from pyqtgraph.Qt import QtCore, QtGui
  import pyqtgraph as pg
  import pyqtgraph.opengl as gl
  import numpy as np
  from scipy import interpolate
  from pylsl import StreamInlet, resolve_stream
  import time
  from scipy.interpolate import griddata

  FFT_MAX_HZ = 20
  
  streams = resolve_stream('type', 'EEG')
  
  inlet = StreamInlet(streams[0])
  
  app = QtGui.QApplication([])
  w = gl.GLViewWidget()
  w.show()
  w.setWindowTitle('pyqtgraph example: GLSurfacePlot')
  w.setCameraPosition(distance=50)
  
  elec_angles = [108,72,144,126,54,36,180,162,18.0,0.0,202.5,225,315,337.5,247.5,292.5]
  freq_radius = [i for i in range(1,21)]
  
  def pol_to_cart_rays(theta,r):
      x = []
      y = []
      ratio = (2*np.pi)/360
      for angle in theta:
          for radius in r:
              x.extend([radius*np.cos(angle*ratio)])
              y.extend([radius*np.sin(angle*ratio)])
  
      return np.asarray(x),np.asarray(y)
  
  x, y = pol_to_cart_rays(elec_angles, freq_radius)
  x_vec = np.linspace(np.min(x),np.max(x),100)
  y_vec =  np.linspace(np.min(y),np.max(y),100)
  X_grid, Y_grid = np.meshgrid(x_vec,y_vec)
  
  
  FFT_MAX = 20
  
  p4 = gl.GLSurfacePlotItem(x=x_vec, y = y_vec, shader='heightColor', computeNormals=False, smooth=False)
  p4.shader()['colorMap'] = np.array([0.2, 2, 0.5, 0.2, 1, 1, 0.2, 0, 2])
  w.addItem(p4)
  
  FFT_dat = np.zeros(x.shape)
  def update():
      global p4, z, index
      for i in range(16): # each of the 16 channels here
          sample, timestamp = inlet.pull_sample()
          FFT_dat[(i*FFT_MAX):(i+1)*FFT_MAX] = np.log(sample[:FFT_MAX])
  
      z_interp = griddata((x, y), FFT_dat, (X_grid, Y_grid), method='cubic')
      p4.setData(z=z_interp)
  
  timer = QtCore.QTimer()
  timer.timeout.connect(update)
  timer.start(40)
  
  
  if __name__ == '__main__':
      import sys
      if (sys.flags.interactive != 1) or not hasattr(QtCore, 'PYQT_VERSION'):
          QtGui.QApplication.instance().exec_()
  
• retiutut Louisiana, USA

  February 2020

  Can you please also share a link to a screen recording with a brief description? This way there is no confusion as to what is actually happening.