A cross-platform driver for bluetooth Neurosky Mindwave headsets.

screenshot of example

There are 2 examples included, and if you'd like to see an example GUI project, check out mindgraph.

I created a C version (based on docs, compiled it to wasm & native, and compared the results between wasm & native, and js. Currently C implementation does not match my javascript:

Wasmer
real 0m0.352s
user 0m0.234s
sys 0m0.158s
136777 test_wasmer.txt
WASI (node)
real 0m0.131s
user 0m0.141s
sys 0m0.010s
136777 test_wasijs.txt
Native (C)
real 0m0.039s
user 0m0.039s
sys 0m0.004s
136777 test_c.txt
Plain JS
real 0m0.992s
user 0m0.843s
sys 0m0.221s
139937 test_js.txt
Files test_c.txt and test_js.txt differ

But I'll be working on fixing it, and update this once I get it squared away. If I can't figure it out, I may just need to parse in C (and use wasm.)

This library uses lower-level serial-over-bluetooth to communicate. For it to work, you will need to pair with it. It should be noted, you can put the headset in pairing-mode by holding up the power until it double-blinks blue (before it turns red.) Solid-blue means you have a working bluetooth/serial connection.

Here is what I did:

• Install gort
• Put headset in "pairing mode" (hold power up until it double-flashes, but before it turns red)
• Run sudo gort scan bluetooth to get mac-address of "MindWave Mobile". Mine was 20:68:9D:4C:0E:93, but yours might be different
• Run sudo gort bluetooth serial 20:68:9D:4C:0E:93 (with your address) to connect headset to a virtual serial port. In my case, it connected to /dev/rfcomm0
• make sure your user is in dialout or whatever group owns that device. sudo adduser konsumer dialout did that for me (requires re-login.)
• verify your connection with node example1.js (or example2.js for a nice graph.)

automation

I recommend you setup your system to automate the connection, which will alleviate connection headaches, and make it mostly just work whenever it's turned on. You can automate the connection on a systemd-based OS (debian, ubuntu, raspbian, etc) by editing /etc/systemd/system/mindwave.service:

[Unit]
Description=Mindwave service
After=bluetooth.service
Requires=bluetooth.service
 
[Service]
ExecStart=/usr/bin/gort bluetooth serial 20:68:9D:4C:0E:93
Restart=always
RestartSec=5s
 
[Install]
WantedBy=multi-user.target

Now run this:

sudo systemctl daemon-reload
sudo systemctl enable mindwave
sudo systemctl start mindwave

Make sure to change 20:68:9D:4C:0E:93 to whatever you discovered in gort scan bluetooth. After all this, it should work anytime the mindwave is turned on (even outside of pairing-mode.) It is contantly restarting gort (every 5s) if it doesn't find the headset, but it has pretty low overhead.

At any time you can get the status:

service mindwave status

I haven't tested as much here, but it should work with built-in windows stuff, setting up SPP (serial over bluetooth) and pairing. You can read more about the process here. In your device manager, under "Advanced" look for the COM port it sets up, and use that in your code. On mine, it was COM4.

Install the official mac driver. You can read more about it here. Your serial-device will be something like /dev/tty.MindWaveMobile-DevA or sometimes /dev/cu.MindWaveMobile-DevA works better (it seemed to have issues rapidly disconnecting and connecting, but changing devices would sometimes fix that.) Make sure to set this at the bottom of the examples, instead of /dev/rfcomm0. Put it in pairing-mode and pair with it, then start your program, and it should go solid-blue and start outputting data.

var Mindwave = require('mindwave')
var mw = new Mindwave()
mw.on('eeg', (eeg) => {
 console.log('eeg', eeg)
});
mw.on('signal', (signal) => {
 console.log('signal', signal)
})
mw.on('attention', (attention) => {
 console.log('attention', attention)
})
mw.on('meditation', (meditation) => {
 console.log('meditation', meditation)
})
mw.on('blink', (blink) => {
 console.log('blink', blink)
})
// These are the raw EEG data
// They come in at about 512Hz
// mw.on('wave', (wave) => {
// console.log('wave', wave)
// })
// common device for mac
// mw.connect('/dev/cu.MindWaveMobile-DevA')
// untested, but I think it's like this on windows:
// mw.connect('COM4')
// linux
mw.connect('/dev/rfcomm0')

• Currently, only 9600 baud is supported, but eventually I will add support for high-resolution data (57600.)
• More cross-platform testing, try to get around having to setup mac driver/rfcomm (maybe with node bluetooth serial lib & web bluetooth API)
• write comparison C function for parsing buffers, and compile for wasm. Do comparioson-tests on real traffic from device. I can verify my js code this way (using reference C implementation in docs) and it might improve performance for js (basically just hook native or web bluetooth API to parsing wasm.) Once I can verify they match, I could try another language I like more, like assmeblyscript or rust (and test them against the js.)