go-bluetooth

Go bluetooth API for Bluez DBus interface.

Usage

1. Build the binary

cd $GOPATH/src/github.com/dimonzozo/go-bluetooth && make build

2. Run the examples eg.

go-bluetooth discovery

The examples/ folder offer an API overview.

Features

The library offers a wrapper to Bluez DBus API and some high level API to ease the interaction.

High level features supported:

• Client code generation from bluez documentation
• Shell wrappers for rfkill, btmgmt, hciconfig, hcitool
• An hci basic API (from a fork of go-ble/ble)
• Expose bluetooth service from go code
• Pairing and authentication support (via agent)
• Basic beaconing (iBeacon and Eddystone)

Setup

The go Bluez API is generated from the documentation, run make gen to re-generate go sources. There is also a commodity bluez JSON file available in the root folder for reference.

Code generation will not overwrite existing files, run make gen/clean to remove generated content.

Generated code has gen_ prefix. If an API file exists with the same filename but without the prefix, generation will be skipped for that API.

Note Ensure to install proper dbus rules on the system. For a dev setup, you can use the library configuration as follow

  cd $GOPATH/src/github.com/dimonzozo/go-bluetooth
  sudo ln -s `pwd`/scripts/dbus-go-bluetooth-service.conf /etc/dbus-1/system.d/
  sudo ln -s `pwd`/scripts/dbus-go-bluetooth-dev.conf /etc/dbus-1/system.d/
  # Reload dbus to load new policies:
  # via dbus
  # dbus-send --system --type=method_call --dest=org.freedesktop.DBus / org.freedesktop.DBus.ReloadConfig
  # via systemctl
  systemctl reload dbus

Requirements

The library is tested with

• golang 1.11
• bluez bluetooth v5.50

Development notes

• Standard GATT characteristics descriptions can be found on https://www.bluetooth.com/specifications/gatt/

• Give access to hciconfig to any user and avoid sudo (may have security implications)

  sudo setcap 'cap_net_raw,cap_net_admin+eip' `which hciconfig`
  

• Monitor Bluetooth activity

  sudo btmon

• Monitor DBus activity

  sudo dbus-monitor --system "type=error"

• Start bluetoothd with experimental features and verbose debug messages make bluetoothd

• Enable LE advertisement (on a single pc ensure to use at least 2x bluetooth adapter)

    sudo btmgmt -i 0 power off
    sudo btmgmt -i 0 name "my go app"
    sudo btmgmt -i 0 le on    
    sudo btmgmt -i 0 connectable on
    sudo btmgmt -i 0 advertising on
    sudo btmgmt -i 0 power on
  

Contributing

Feel free to open an issue and/or a PR to contribute. If you would like to help improve the library without coding directly, you can also consider to contribute by providing some hardware to test on.

References

• https://git.kernel.org/cgit/bluetooth/bluez.git/tree/doc
• https://www.bluetooth.com/specifications/gatt/services
• http://events.linuxfoundation.org/sites/events/files/slides/Bluetooth%20on%20Modern%20Linux_0.pdf
• https://github.com/nettlep/gobbledegook
• https://dbus.freedesktop.org/doc/dbus-specification.html#type-system
• http://processors.wiki.ti.com/images/a/a8/BLE_SensorTag_GATT_Server.pdf
• https://git.kernel.org/cgit/bluetooth/bluez.git/tree/doc

License

Copyright 2019 luca capra

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.