openbci-ganglion v1.2.0

OpenBCI Node.js Ganglion SDK

A Node.js module for OpenBCI.

We are proud to support all functionality of the Ganglion (4 channel).

The purpose of this module is to get connected and start streaming as fast as possible.

Table of Contents:

1. TL;DR
2. Prerequisites
3. Installation
4. Ganglion
5. General Overview
6. SDK Reference Guide
   • Events
7. Interfacing With Other Tools
8. Developing
9. Testing
10. Contribute
11. License
12. Roadmap

TL;DR:

Get connected and start streaming right now

const Ganglion = require("openbci-ganglion");
const ganglion = new Ganglion();
ganglion.once("ganglionFound", peripheral => {
  // Stop searching for BLE devices once a ganglion is found.
  ganglion.searchStop();
  ganglion.on("sample", sample => {
    /** Work with sample */
    console.log(sample.sampleNumber);
    for (let i = 0; i < ganglion.numberOfChannels(); i++) {
      console.log(
        "Channel " +
          (i + 1) +
          ": " +
          sample.channelData[i].toFixed(8) +
          " Volts."
      );
    }
  });
  ganglion.once("ready", () => {
    ganglion.streamStart();
  });
  ganglion.connect(peripheral);
});
// Start scanning for BLE devices
ganglion.searchStart();

Prerequisites:

Please ensure Python 2.7 is installed for all OS.

macOS

• install Xcode

Linux

• Kernel version 3.6 or above
• libbluetooth-dev
• libudev-dev

Running without sudo

In order to stream data on Linux without root/sudo access, you may need to give the node binary privileges to start and stop BLE advertising.

sudo setcap cap_net_raw+eip $(eval readlink -f `which node`)

Note: this command requires setcap to be installed. Install it with the libcap2-bin package.

sudo apt-get install libcap2-bin

Windows 8+

• node-gyp requirements for Windows
  • Python 2.7
  • Visual Studio (Express)
• node-bluetooth-hci-socket prerequisites
  • Compatible Bluetooth 4.0 USB adapter
  • WinUSB driver setup for Bluetooth 4.0 USB adapter, using Zadig tool

See @don's set up guide on Bluetooth LE with Node.js and Noble on Windows.

Installation:

Install from npm:

npm install openbci-ganglion

About:

The Ganglion driver used by OpenBCI's Processing GUI and Electron Hub.

Check out the automatic tests written for it!

General Overview:

Initialization

Initializing the board:

const Ganglion = require("openbci-ganglion");
const ganglion = new Ganglion();

For initializing with options, such as verbose print outs:

const Ganglion = require("openbci-ganglion");
const ourBoard = new Ganglion({
  verbose: true
});

For initializing with callback, such as to catch errors on noble startup:

const Ganglion = require("openbci-ganglion");
const ourBoard = new Ganglion(error => {
  if (error) {
    console.log("error", error);
  } else {
    console.log("no error");
  }
});

For initializing with options and callback, such as verbose and to catch errors on noble startup:

const Ganglion = require("openbci-ganglion");
const ourBoard = new Ganglion(
  {
    verbose: true
  },
  error => {
    if (error) {
      console.log("error", error);
    } else {
      console.log("no error");
    }
  }
);

'ready' event

You MUST wait for the 'ready' event to be emitted before streaming/talking with the board. The ready happens asynchronously so installing the 'sample' listener and writing before the ready event might result in... nothing at all.

const Ganglion = require("openbci-ganglion");
const ourBoard = new Ganglion();
ourBoard
  .connect(portName)
  .then(function(boardSerial) {
    ourBoard.on("ready", function() {
      /** Start streaming, reading registers, what ever your heart desires  */
    });
  })
  .catch(function(err) {
    /** Handle connection errors */
  });

Sample properties:

• sampleNumber (a Number between 0-255)
• channelData (channel data indexed at 0 filled with floating point Numbers in Volts)
• accelData (Array with X, Y, Z accelerometer values when new data available)
• timeStamp (Number the boardTime plus the NTP calculated offset)

The power of this module is in using the sample emitter, to be provided with samples to do with as you wish.

To get a 'sample' event, you need to:

1. Call .connect(localName | peripheral)
2. Install the 'ready' event emitter on resolved promise
3. In callback for 'ready' emitter, call streamStart()
4. Install the 'sample' event emitter

const Ganglion = require("openbci-ganglion");
const ourBoard = new Ganglion();
ourBoard
  .connect(localName)
  .then(function() {
    ourBoard.on("ready", function() {
      ourBoard.streamStart();
      ourBoard.on("sample", function(sample) {
        /** Work with sample */
      });
    });
  })
  .catch(function(err) {
    /** Handle connection errors */
  });

Close the connection with .streamStop() and disconnect with .disconnect()

const Ganglion = require("openbci-ganglion");
const ourBoard = new Ganglion();
ourBoard.streamStop().then(ourBoard.disconnect());

See Reference Guide for a complete list of impedance tests.

SDK Reference Guide:

Classes

Typedefs

Ganglion

Kind: global class
Author: AJ Keller (@pushtheworldllc)

• Ganglion
  • new Ganglion(options, callback)
  • instance
    • .options : InitializationObject
    • ._accelArray
    • ._bled112WriteCharacteristic : BLED112FindInformationFound
    • .buffer
    • .accelStart() ⇒ Promise
    • .accelStop() ⇒ Promise
    • .autoReconnect()
    • .channelOff(channelNumber) ⇒ Promise.<T>
    • .channelOn(channelNumber) ⇒ Promise.<T> | *
    • .cleanupEmitters()
    • .connect(id) ⇒ Promise
    • .destroyNoble()
    • .destroyBLED112()
    • .destroyMultiPacketBuffer()
    • .disconnect(stopStreaming) ⇒ Promise
    • .getLocalName() ⇒ null | String
    • .getMutliPacketBuffer() ⇒ null | Buffer
    • .impedanceStart() ⇒ global.Promise | Promise
    • .impedanceStop() ⇒ global.Promise | Promise
    • .initDriver() ⇒ Promise.<any>
    • .isConnected() ⇒ boolean
    • .isNobleReady() ⇒ boolean
    • .isSearching() ⇒ boolean
    • .isStreaming() ⇒ boolean
    • .numberOfChannels() ⇒ Number
    • .printRegisterSettings() ⇒ Promise.<T> | *
    • .sampleRate() ⇒ Number
    • .searchStart(`maxSearchTime`) ⇒ Promise
    • .searchStop() ⇒ global.Promise | Promise
    • .softReset() ⇒ Promise
    • .streamStart() ⇒ Promise
    • .streamStop() ⇒ Promise
    • .syntheticEnable() ⇒ Promise
    • .syntheticDisable() ⇒ Promise
    • .write(data) ⇒ Promise
    • ._bled112WriteAndDrain(data) ⇒ Promise
  • inner
    • ~o

new Ganglion(options, callback)

The initialization method to call first, before any other method.

ganglion.options : InitializationObject

Kind: instance property of Ganglion

ganglion._accelArray

Private Properties (keep alphabetical)

Kind: instance property of Ganglion

ganglion._bled112WriteCharacteristic : BLED112FindInformationFound

Kind: instance property of Ganglion

ganglion.buffer

Public Properties (keep alphabetical)

Kind: instance property of Ganglion

ganglion.accelStart() ⇒ Promise

Used to enable the accelerometer. Will result in accelerometer packets arriving 10 times a second. Note that the accelerometer is enabled by default.

Kind: instance method of Ganglion

ganglion.accelStop() ⇒ Promise

Used to disable the accelerometer. Prevents accelerometer data packets from arriving.

Kind: instance method of Ganglion

ganglion.autoReconnect()

Used to start a scan if power is on. Useful if a connection is dropped.

Kind: instance method of Ganglion

ganglion.channelOff(channelNumber) ⇒ Promise.<T>

Send a command to the board to turn a specified channel off

Kind: instance method of Ganglion
Author: AJ Keller (@pushtheworldllc)

ganglion.channelOn(channelNumber) ⇒ Promise.<T> | *

Send a command to the board to turn a specified channel on

Kind: instance method of Ganglion
Author: AJ Keller (@pushtheworldllc)

ganglion.cleanupEmitters()

Used to clean up emitters

Kind: instance method of Ganglion

ganglion.connect(id) ⇒ Promise

The essential precursor method to be called initially to establish a ble connection to the OpenBCI ganglion board.

Kind: instance method of Ganglion
Returns: Promise - If the board was able to connect.
Author: AJ Keller (@pushtheworldllc)

ganglion.destroyNoble()

Destroys the noble!

Kind: instance method of Ganglion

ganglion.destroyBLED112()

Destroys the noble!

Kind: instance method of Ganglion

ganglion.destroyMultiPacketBuffer()

Destroys the multi packet buffer.

Kind: instance method of Ganglion

ganglion.disconnect(stopStreaming) ⇒ Promise

Closes the connection to the board. Waits for stop streaming command to be sent if currently streaming.

Kind: instance method of Ganglion
Returns: Promise - - fulfilled by a successful close, rejected otherwise.
Author: AJ Keller (@pushtheworldllc)

ganglion.getLocalName() ⇒ null | String

Return the local name of the attached Ganglion device.

Kind: instance method of Ganglion

ganglion.getMutliPacketBuffer() ⇒ null | Buffer

Get's the multi packet buffer.

Kind: instance method of Ganglion
Returns: null | Buffer - - Can be null if no multi packets received.

ganglion.impedanceStart() ⇒ global.Promise | Promise

Call to start testing impedance.

Kind: instance method of Ganglion

ganglion.impedanceStop() ⇒ global.Promise | Promise

Call to stop testing impedance.

Kind: instance method of Ganglion

ganglion.initDriver() ⇒ Promise.<any>

Initialize the drivers

Kind: instance method of Ganglion

ganglion.isConnected() ⇒ boolean

Checks if the driver is connected to a board.

Kind: instance method of Ganglion
Returns: boolean - - True if connected.

ganglion.isNobleReady() ⇒ boolean

Checks if bluetooth is powered on.

Kind: instance method of Ganglion
Returns: boolean - - True if bluetooth is powered on.

ganglion.isSearching() ⇒ boolean

Checks if noble is currently scanning.

Kind: instance method of Ganglion
Returns: boolean - - True if streaming.

ganglion.isStreaming() ⇒ boolean

Checks if the board is currently sending samples.

Kind: instance method of Ganglion
Returns: boolean - - True if streaming.

ganglion.numberOfChannels() ⇒ Number

This function is used as a convenience method to determine how many channels the current board is using.

Kind: instance method of Ganglion
Returns: Number - A number Note: This is dependent on if you configured the board correctly on setup options
Author: AJ Keller (@pushtheworldllc)

ganglion.printRegisterSettings() ⇒ Promise.<T> | *

To print out the register settings to the console

Kind: instance method of Ganglion
Author: AJ Keller (@pushtheworldllc)

ganglion.sampleRate() ⇒ Number

Get the the current sample rate is.

Kind: instance method of Ganglion
Returns: Number - The sample rate Note: This is dependent on if you configured the board correctly on setup options

ganglion.searchStart(`maxSearchTime`) ⇒ Promise

List available peripherals so the user can choose a device when not automatically found.

Kind: instance method of Ganglion
Returns: Promise - - If scan was started

ganglion.searchStop() ⇒ global.Promise | Promise

Called to end a search.

Kind: instance method of Ganglion

ganglion.softReset() ⇒ Promise

Sends a soft reset command to the board

Kind: instance method of Ganglion
Returns: Promise - - Fulfilled if the command was sent to board.
Author: AJ Keller (@pushtheworldllc)

ganglion.streamStart() ⇒ Promise

Sends a start streaming command to the board.

Kind: instance method of Ganglion
Returns: Promise - indicating if the signal was able to be sent. Note: You must have successfully connected to an OpenBCI board using the connect method. Just because the signal was able to be sent to the board, does not mean the board will start streaming.
Author: AJ Keller (@pushtheworldllc)

ganglion.streamStop() ⇒ Promise

Sends a stop streaming command to the board.

Kind: instance method of Ganglion
Returns: Promise - indicating if the signal was able to be sent. Note: You must have successfully connected to an OpenBCI board using the connect method. Just because the signal was able to be sent to the board, does not mean the board stopped streaming.
Author: AJ Keller (@pushtheworldllc)

ganglion.syntheticEnable() ⇒ Promise

Puts the board in synthetic data generation mode. Must call streamStart still.

Kind: instance method of Ganglion
Returns: Promise - indicating if the signal was able to be sent.
Author: AJ Keller (@pushtheworldllc)

ganglion.syntheticDisable() ⇒ Promise

Takes the board out of synthetic data generation mode. Must call streamStart still.

Kind: instance method of Ganglion
Returns: Promise - - fulfilled if the command was sent.
Author: AJ Keller (@pushtheworldllc)

ganglion.write(data) ⇒ Promise

Used to send data to the board.

Kind: instance method of Ganglion
Returns: Promise - - fulfilled if command was able to be sent
Author: AJ Keller (@pushtheworldllc)

Example

Sends a single character command to the board.

// ourBoard has fulfilled the promise on .connect() and 'ready' has been observed previously
ourBoard.write("a");

Sends an array of bytes

// ourBoard has fulfilled the promise on .connect() and 'ready' has been observed previously
ourBoard.write(["x", "0", "1", "0", "0", "0", "0", "0", "0", "X"]);

Call crazy? Go for it...

ourBoard.write("t");
ourBoard.write("a");
ourBoard.write("c");
ourBoard.write("o");

ganglion._bled112WriteAndDrain(data) ⇒ Promise

Should be used to send data to the board

Kind: instance method of Ganglion
Returns: Promise - if signal was able to be sent
Author: AJ Keller (@pushtheworldllc)

Ganglion~o

Configuring Options

Kind: inner property of Ganglion

kOBCIBLED112ParsingConnectDirect

Used in parsing incoming serial data

Kind: global constant

InitializationObject : Object

Board optional configurations.

Kind: global typedef
Properties

BLED112AttributeValue : Object

Kind: global typedef
Properties

BLED112AttributeWrite : Object

Kind: global typedef
Properties

BLEDConnection : Object

Kind: global typedef
Properties

BLED112FindInformationFound : Object

Kind: global typedef
Properties

BLED112GapConnectDirect : Object

Kind: global typedef
Properties

BLED112GroupService : Object

Kind: global typedef
Properties

BLED112ParseRawAttributeValue : Object

Kind: global typedef
Properties

BLED112ParseRawHeadTail : Object

Kind: global typedef
Properties

BLED112ParseRawWord : Object

Kind: global typedef
Properties

BLED112Peripheral : Object

Kind: global typedef
Properties

BLED112RspGroupType : Object

Kind: global typedef
Properties

Events:

.on('accelerometer', callback)

Emitted when the module receives accelerometer data.

Returns an object with properties:

accelData {Array}

Array of floats for each dimension in g's.

NOTE: Only present if sendCounts is true.

accelDataCounts {Array}

Array of integers for each dimension in counts.

NOTE: Only present if sendCounts is false.

Example (if sendCounts is false):

{
  "accelData": [0.0, 0.0, 0.0, 0.0]
}

Example (if sendCounts is true):

{
  "accelDataCounts": [0, 0, 0, 0]
}

.on('droppedPacket', callback)

Emitted when a packet (or packets) are dropped. Returns an array.

.on('error', callback)

Emitted when there is an on the serial port.

.on('impedance', callback)

Emitted when there is a new impedance available.

Returns an object with properties:

channelNumber {Number}

The channel number: 1, 2, 3, 4 respectively and 0 for reference.

impedanceValue {Number}

The impedance in ohms.

Example:

{
  "channelNumber": 0,
  "impedanceValue": 0
}

.on('rawDataPacket', callback)

Emitted when there is a new raw data packet available.

.on('ready', callback)

Emitted when the board is in a ready to start streaming state.

.on('sample', callback)

Emitted when there is a new sample available.

Returns an object with properties:

channelData {Array}

Array of floats for each channel in volts..

NOTE: Only present if sendCounts is true.

channelDataCounts {Array}

Array of integers for each channel in counts.

NOTE: Only present if sendCounts is false.

sampleNumber {Number}

The sample number. Only goes up to 254.

timeStamp {Number}

The time the sample is packed up. Not accurate for ERP.

Example (if sendCounts is false):

{
  "channelData": [0.0, 0.0, 0.0, 0.0],
  "sampleNumber": 0,
  "timeStamp": 0
}

Example (if sendCounts is true):

{
  "channelDataCounts": [0, 0, 0, 0],
  "sampleNumber": 0,
  "timeStamp": 0
}

.on('scanStart', callback)

Emitted when a noble scan is started.

.on('scanStop', callback)

Emitted when a noble scan is stopped.

Interfacing With Other Tools:

LabStreamingLayer

LabStreamingLayer is a tool for streaming or recording time-series data. It can be used to interface with Matlab, Python, Unity, and many other programs.

To use LSL with the NodeJS SDK, go to our labstreaminglayer example, which contains code that is ready to start an LSL stream of OpenBCI data.

Follow the directions in the readme to get started.

Developing:

Running:

npm install

Testing:

npm test

Contribute:

1. Fork it!
2. Branch off of development: git checkout development
3. Create your feature branch: git checkout -b my-new-feature
4. Make changes
5. If adding a feature, please add test coverage.
6. Ensure tests all pass. (npm test)
7. Commit your changes: git commit -m 'Add some feature'
8. Push to the branch: git push origin my-new-feature
9. Submit a pull request. Make sure it is based off of the development branch when submitting! :D

License:

MIT