Fix bug streaming Band Power over LSL for all channels

Author: retiutut

Networking-Test-Kit/LSL/lslStreamTest_BandPowerAllChannels.py

@@ -1,41 +1,44 @@
-"""Example program to show how to read a multi-channel time series from LSL."""
+"""Example program to show how to read a GUI BandPower data over LSL."""
 import time
 from pylsl import StreamInlet, resolve_stream
 from time import sleep
 
-# first resolve an EEG stream on the lab network
+# Example Sample
+# F
+#[0.0, 0.8485075831413269, 9.373364448547363, 0.0013413801789283752, 0.001849484397098422]
+
+# First resolve an EEG stream on the lab network
 print("looking for an EEG stream...")
 streams = resolve_stream('type', 'EEG')
 
-# create a new inlet to read from the stream
+# Create a new inlet to read from the stream
 inlet = StreamInlet(streams[0])
-duration = 10
+duration = 5
+num_channels = 8
 
 sleep(1)
 
 def testLSLSamplingRate():
     start = time.time()
-    totalNumSamples = 0
-    validSamples = 0
-    numChunks = 0
+    total_samples = 0
+    num_samples_channel_0 = 0
     print( "Testing Sampling Rates..." )
 
     while time.time() <= start + duration:
-        # get chunks of samples
-        chunk, timestamp = inlet.pull_chunk()
-        if timestamp:
-            print("\nNew chunk! Chunk size == {}".format(len(chunk)) )
-            numChunks += 1
-            totalNumSamples += len(chunk)
-            print(chunk, timestamp)
-            for sample in chunk:
-                #print(sample)
-                validSamples += 1
-
-    print( "Number of Chunks and Samples == {} , {}".format(numChunks, totalNumSamples) )
-    print( "Average Number of Samples per Chunk == {}".format(totalNumSamples / numChunks) )
-    print( "Valid Chunks and Duration == {} / {}".format(numChunks, duration) )
-    print( "Average Sampling Rate == {}".format(numChunks / duration) )
+        # Get chunks of samples
+        sample, timestamp = inlet.pull_sample()
+        if sample:
+            print("\nNew chunk! Sample size == {}".format(len(sample)) )
+            total_samples += 1
+            print(sample, timestamp)
+            if sample[0] == 0.0:
+                num_samples_channel_0 += 1
+
+
+    print( "Valid Samples and Duration == {} / {}".format(total_samples, duration) )
+    print( "Average Sampling Rate == {}".format(total_samples / duration) )
+    print( "Valid Samples Channel 0 and Duration == {} / {}".format(num_samples_channel_0, duration) )
+    print( "Average Sampling Rate Channel 0 == {}".format(num_samples_channel_0 / duration) )
 
 
 testLSLSamplingRate()

OpenBCI_GUI/NetworkStreamOut.pde

@@ -527,17 +527,23 @@ class NetworkStreamOut extends Thread {
 
         } else if (this.protocol.equals("LSL")) {
 
-            // DELTA, THETA, ALPHA, BETA, GAMMA
+            // Send out band powers for each channel sequentially via push_sample
+            // Prepend channel number to each array
+            // push_chunk will send out all channels at once...but doesn't seem to gaurantee all X channels of data will be pulled at once, despite extensive testing
+            // Example sample: [Channel Number, DELTA, THETA, ALPHA, BETA, GAMMA]
+            // [0.0, 0.8451713919639587, 9.27791690826416, 0.00044474846799857914, 0.0014277123846113682, 0.0029974353965371847]
             int numChannels = numExgChannels;
-            float[] dataToSend = new float[numChannels * NUM_BAND_POWERS];
-            for (int band = 0; band < NUM_BAND_POWERS; band++) {
-                for (int channel = 0; channel < numChannels; channel++) {
-                    dataToSend[channel + band * numChannels] = dataProcessing.avgPowerInBins[channel][band];
+            float[] dataToSend = new float[NUM_BAND_POWERS + 1];
+            for (int channel = 0; channel < numChannels; channel++) {
+                for (int band = 0; band < NUM_BAND_POWERS + 1; band++) {
+                    if (band == 0) {
+                        dataToSend[band] = (float) channel;
+                    } else {
+                        dataToSend[band] = dataProcessing.avgPowerInBins[channel][band - 1];
+                    }
                 }
+                outlet_data.push_sample(dataToSend);
             }
-            double unixTime = System.currentTimeMillis() / 1000d;
-            //println(unixTime);
-            outlet_data.push_chunk(dataToSend, unixTime, true);
 
         } else if (this.protocol.equals("Serial")) {
             for (int i = 0; i < numExgChannels; i++) {

OpenBCI_GUI/W_Networking.pde

@@ -1084,7 +1084,9 @@ class W_Networking extends Widget {
         } else if (dataType.equals("AvgBandPower")) {
             return 5;
         } else if (dataType.equals("BandPower")) {
-            return 5;
+            //Send out band powers for each channel sequentially
+            //Prepend channel number to each array
+            return 5 + 1;
         } else if (dataType.equals("Pulse")) {
             return 2;
         } else if (dataType.equals("Accel/Aux")) {