Simple sketch that scans OpenBCI data files to check for any dropped packets The program will prompt you to select a file, then it will scan the sample counter on each line of data to check for dropped packets. After it reads the file, it will print the results in the terminal window in Processing. It will also creat a small text file in the sketch folder with the scan results. Here's an example of the output

mouse pressed
User selected /Users/biomurph/Documents/OpenBCI/Verification/Burke/SavedData\OpenBCI-RAW-Kelsey-2.csv
timing file verification
%OpenBCI Raw EEG Data
%
%Sample Rate = 250.0 Hz
%First Column = SampleIndex
%Other Columns = EEG data in microvolts with optional columns at end being unscaled Aux data
At line 6  96 packets dropped
At line 15893  1 packets dropped
read 20320 lines
nothing left in file
verify took 53 mS

The first lines show which file was selected, the lines following that begin with % are copied from the OpenBCI data file (OpenBCI uses % as prefix for comments in the data files)

Each line in the data file is a sample. Line 6 contains the very first sample, and the OpenBCI sampleCounter does not always start at 0, so line 6 will likely show some erroneous number of packets dropped. Please ignore line 6 until we fix the bug... So this shows that at sample #15893, 1 packet was dropped, and that's it out of a total of 20320 samples.