Now a walk-through (Part 3 of 3) of using your Mindwave and OpenVibe to save a sample of your brainwaves to a file.
Start Neurosky’s “Thinkgear Connector”, and make sure the “Starting port” is correct.
Start “openvibe acquisition server”, and choose a driver “Neurosky Mindset”
Click on “Driver Properties”, and make sure the “COM Port” is correct” and you’ll want a “Sampling frequency” of 512.
Click on “Connect”, then once it is connected, click on “Play”.
Going back to the “openvibe designer”, click on “Acquisition-Signal-Display.xml”, then click on the little arrow at the top menu, and a box with pop up showing your brainwaves! To stop, click on the little box at the top menu.
Next click on “Acquisition-File-CSV.xml”, then double-click on the “CSV File writer” to remind you that (as previously saved in Part 2) the file will be “c:/OpenVibe/hello.csv” and close the CSV File Write Settings box.
Click on the the little arrow on at the top menu and start recording your brainwaves to a file. Wait for however long you want the recording, then click on the little box at the top menu, to stop recording.
Now, I would stop OpenVibe, take off the Mindwave, and have a look at “c:/OpenVibe/hello.csv”. Using Excel, here is what the file looks like:
You’ll notice that all the information is in one column. To move the info into separate columns:
- highlight the one column with all the info
- click on “Data” in the top menu
- click on “Text to Columns”
- the column wizard pops up, choose “Delimited”, then click on Next
- checkmark semicolon (and uncheck tab), then click Next
- then click on “Finish”
You’ll notice under “Sampling Rate”, it says 512. That means there are 512 records per second , which is the standard for EEG machines. Under “Electrodes” is the raw data, and under “Attention” and “Meditation” are the numbers showing home much your brain is focused or relaxing (based on a Neurosky algorithm).
To graph one second, delete all the info after line 513, then highlight the columns, click on “Insert” and then click on “Scatter”, then choose “Scatter with Smooth Lines”
One second of your brainwaves graphed:
So what does this graph mean? I haven’t a clue, but it is a good first step on the journey to understanding brainwaves.