Ubuntu Bluetooth HID keyboard Emulation / Mirroring

Emulates a Bluetooth HID keyboard by mirroring / sharing keystrokes from an attached (or internal) keyboard on a Ubuntu device or sending (multiple) virtual key events via a python script

requirements:

• Ubuntu (16.04) device with working Bluetooth BlueZ stack
• python 2.7 with Pybluez, evdev module

test configuration:

Ubuntu 16.04 (4.4.0-24-generic kernel) amd64 - BlueZ 5.37 Python 2.7.12 (PyBluez 0.22, evdev 0.7) Intel® Centrino® Advanced-N 6235, Dualband bluetooth chipset Sony D5803 Android 6 smartphone (bluetooth HID v1.1 host role)

Step 1: Install requirements and configure setup

• run sudo ./setup.sh
• if the keyboard you want to use is not /dev/input/event4 change self.dev = InputDevice("/dev/input/event4") in the keyboard/kb_client.py file. You can determine what your keyboard is by running the command sudo evtest
• if you want to deploy this tool on multiple devices you should change the advertised bluetooth name in the startup script

Step 2: Run

• sudo ./start.sh runs necessary steps to expose your keyboard as Bluetooth HID device
• sudo tmux a opens up the "command center"
• now connect and pair your BT_Keyb on your target device (e.g. Android device)

Step 3: Pause sharing keyboard

• by clicking in the right lower corner and pushing CTRL-C while your keyboard is mirrored you can interrupt mirroring the Keyboard
• by rerunning sudo python kb_client.py you start sharing your keyboard again

NOTE: Every key you press will usually trigger an action on both devices!!! So be careful in what you are typing! Best seems if you open a text editor and type there. The reason for reading from the raw event file is that it allows to catch alt-tab key combination and media keys (play, next track, etc.) in an easy way. Feel free to extend this tool by an additional keyboard-client and create a pull request if you know how to write a special window which will forward all keyboard events only to the bluetooth server as long as it is focussed (without loosing focus on alt-tab events).

Step 4: Terminate the tool

go to the "command center" window and push CTRL-b followed by & and y (simply closing the console won't terminate the tool!)

Disclaimer:

This tool is a slightly modified version of https://github.com/quangthanh010290/BL_keyboard_RPI in order to work for ubuntu. See this tutorial http://www.mlabviet.com/2017/09/make-raspberry-pi3-as-emulator.html as well as this video demo for a step by step installation guide.

Troubleshooting

Bluetooth server

sudo /etc/init.d/bluetooth stop
sudo killall bluetoothd
sudo /usr/sbin/bluetoothd --nodetach --debug -p time

Pairing

Note that for the pairing process, you may need to do the following:

sudo /usr/bin/bluetoothctl

> agent on
> default-agent
> scan on
> discoverable on