bluez Profile API bindings

this gem allows easy creation of bluetooth services. For example create a serial link over to another device using bluetooth.

https://github.com/pauloborges/bluez/blob/master/doc/profile-api.txt

Clive Andrews 2021

dependencies

• Linux/Unix type system
• bluez 5
• glib-2 (dev)

prerequisites

your bluetooth devices must be paired and trusted outside of this gem in order for them to communicate.

use eg bluetoothctl

API

example code:

class MyProfile < Bluez::Profile

  # This method gets called when the service daemon
  # unregisters the profile. A profile can use it to do
  # cleanup tasks.

  def release

  end

  # This method gets called when a new service level
  # connection has been made and authorized.

  def  connection(device, fd, fd_properties)

  end

  # This method gets called when a profile gets
  # disconnected.
  #
  # The file descriptor is no longer owned by the service
  # daemon and the profile implementation needs to take
  # care of cleaning up all connections.
  #
  # If multiple file descriptors are indicated via
  # NewConnection, it is expected that all of them
  # are disconnected before returning from this
  # method call.

  def disconnection(device)

  end

end

path = '/my/dbus/path'
uuid = '1101'

options = {
  name: 'my profile',
  channel: 3
  connect: false
}

profile = MyProfile.new(path, uuid, options)
profile.run   # enters loop and blocks here.

profile.stop  # stops the loop

path: string

the dbus object path of the profile.
eg: "/serial/special/profile"

uuid: string

the dbus profile uuid

Available options:

    name: string

      Human readable name for the profile

    service: string

      The primary service class UUID
      (if different from the actual
       profile UUID)

    role: string

      For asymmetric profiles that do not
      have UUIDs available to uniquely
      identify each side this
      parameter allows specifying the
      precise local role.

      Possible values:

          Bluez::Profile::Client
          Bluez::Profile::Server

    channel: int

      RFCOMM channel number that is used
      for client and server UUIDs.

      If applicable it will be used in the
      SDP record as well.

    psm: int

      PSM number that is used for client
      and server UUIDs.

      If applicable it will be used in the
      SDP record as well.

    authentication: boolean

      Pairing is required before connections
      will be established. No devices will
      be connected if not paired.

    authorization: boolean

      Request authorization before any
      connection will be established.

    connect: boolean

      In case of a client UUID this will
      force connection of the RFCOMM or
      L2CAP channels when a remote device
      is connected.

    record: string

      Provide a manual SDP record.

    version: int

      Profile version (for SDP record)

    features: int

      Profile features (for SDP record)

server

If a channel number is already in use your service may not be registered. Check that your services have been registered correctly with eg:

sudo sdptool browse local

examples

See the /examples folder.

issues

The server side of things seems to work fine.

run several servers over the same serial service using different channel numbers

on the client ( paired and trusted) connect each channel eg :

sudo rfcomm connect /dev/rfcomm0 remoteaddr channel1
sudo rfcomm connect /dev/rfcomm1 remoteaddr channel2
sudo rfcomm connect /dev/rfcomm2 remoteaddr channel3

this works perfectly. each device file allows interaction with the correct server.

BUT if on the client a profile is registered with bluez using this gem and a connection made to the server then things get in a muddle and output for the one channel gets sent to the wrong profile !!

any ideas ??