hci-socket

node-hci-socket

Linux bindings for using a Bluetooth controller in Node.js over HCI.

This module uses the HCI_CHANNEL_USER feature in the Linux kernel, allowing a process to communicate over HCI directly with a Bluetooth controller.

Setup

Installation:

npm install hci-socket

Usage

Include the HciSocket class:

const HciSocket = require('hci-socket');

List devices:

> HciSocket.getDevList();

[
  {
    devId: 0,
    name: 'hci0',
    bdaddr: 'XX:XX:XX:XX:XX:XX',
    flags: 0,
    type: 'PRIMARY',
    bus: 'USB'
  }
]

Get info about a specific devId:

> HciSocket.getDevInfo(0);

{
  devId: 0,
  name: 'hci0',
  bdaddr: 'XX:XX:XX:XX:XX:XX',
  flags: 0,
  type: 'PRIMARY',
  bus: 'USB'
}

An Error with code 'ENODEV' will be thrown if not found.

Create a HciSocket instance:

var socket = new HciSocket(); // To create a socket for the first found hci device
// OR
var socket = new HciSocket(devId);

• An Error with code 'ENODEV' will be thrown if not found.
• An Error with code 'EBUSY' will be thrown if the device is already in use. You could try to stop bluetoothd if it is running.
• An Error with code 'EPERM' will be thrown if the node process does not have permissions to use the socket. Execute sudo setcap cap_net_admin=ep $(eval readlink -f `which node`) first or run node using sudo.

The HciSocket instance has two methods.

Write a packet:

socket.write(Buffer.from([0x01, 0x03, 0x0C, 0x00])); // sends a Reset command

The packet format used is the same as specified in the Bluetooth Core specification, Vol 4: Host Controller Interface, Part A: UART Transport Layer, Chapter 2: Protocol. Note that even if for example a USB Bluetooth controller is used, the Linux kernel will automatically convert it into this format.

An exception will be thrown if the socket has been closed, or if the argument is not a Buffer with length between 4 and 1028.

Close a socket:

socket.close();

The HciSocket instance has two events defined.

A packet arrives:

socket.on('data', function(buffer) { ... });

The socket gets closed, either explicitly after calling close(), or automatically if the device gets unplugged from the system:

socket.on('close', function() { ... });

A HciSocket instance that has not been closed will keep the node process from exiting.