btkbdd(8)

1BTKBDD(1)                 System management commands                 BTKBDD(1)
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NAME

6       btkbdd - Bluetooth Keyboard Daemon
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SYNOPSIS

9       btkbdd [-s addr] [-t addr] [-c file] [-d] device
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DESCRIPTION

12       This tool starts a Bluetooth HID Keyboard service, serving keystrokes
13       obtained via Linux Input subsystem's event device (evdev).  In
14       practical terms, it turns your Linux box with a physical keyboard into
15       a Bluetooth keyboard, which can be used by various Bluetooth HID
16       capable devices, including desktop or tablet computers, smart phones,
17       game consoles and so on.
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19       It implements most of the important HID protocol features, including
20       robust connection restores (virtual cabling) and report protocol (as
21       required by Apple's Darwin-based devices). It is possible and
22       encouraged to use the tool from udev, starting it when event devices
23       appear after a keyboard is plugged in.
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OPTIONS

26       -s addr
27           Accept connections on given Bluetooth address. Useful when your
28           computer has multiple Bluetooth Host Controller Interfaces (HCI).
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30           Class of this device is changed into keyboard while the program is
31           running and restored upon termination.
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33           Defaults to accepting connections on any interface, while changing
34           the class only of the first interface hci0, which is a sane default
35           for computers with a single HCI.
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37       -t addr
38           Attempt connecting to given address upon key press, if no
39           connection has been estabilished yet. This can be used to
40           effectively "hardwire" the keyboard to a given host.
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42           Once an incoming connection is estabilished and terminated, btkbdd
43           always tries to restore it upon a key press event.
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45       -c file
46           Save the last connected remote address into given file upon
47           termination and restore it on startup.
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49           Use this option if you want to remember last connected device
50           between btkbdd runs.
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52       -d  Become a daemon.  Give up controlling terminal, open file
53           descriptors and double-fork to escape parent process control.
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55           While breaking process hierarchy has certain disadvantages and is
56           deprecated with modern service control daemons such as systemd(8)),
57           it is necessary to do so with udevd(8), otherwise btkbdd would
58           block the whole worker process.
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60       device
61           Linux input subsystem event device to use as source for key
62           presses.
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EXAMPLES

65       Use with udev(7) and systemd(1) is recommended. Look into
66       90-btkbdd.rules and btkbdd@.service files distributed with btkbdd for
67       examples.
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69       btkbdd /dev/input/event8
70           Most basic usage -- just open a keyboard device and listen for
71           incoming connections.  When in doubt about which physical device
72           corresponds to an event device node, use "udevadm info
73           --attribute-walk --name=file" to identify the device and its
74           connection details.
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76       btkbdd /dev/input/event8 -s EC:55:F9:EF:12:34 -c
77       /var/lib/btkbdd/keyboard.cable
78           Only accept connections on given HCI and remember the connected
79           device.  You can discover your HCI device addresses with "hcitool
80           dev" command.
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82       btkbdd /dev/input/event8 -t EC:55:F9:EF:56:78
83           Initiate a connection to given Bluetooth host.  You can discover
84           available devices with "hcitool scan".
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BUGS

87       Bluez bluetoothd(8) daemon is likely to listen for HID events. For
88       btkbdd to accept connection you need to disable the Bluez input plugin
89       by setting "DisablePlugins = input" in /etc/bluetooth/main.conf.
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91       Nothing but errors is logged and when in daemon mode even the error
92       output is lost. Attach strace(1) or launch btkbdd manually to
93       troubleshoot errors.
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95       Only a common 101-key keyboard is supported.
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97       To estabilish pairing with iPad, iPod Touch or iPhone, connection must
98       be initiated and authenticated via bluetooth-applet(1) before starting
99       btkbdd. Otherwise the device will initiate a PIN-based authentication
100       that is not supported. Once trust is estabilished, connections will
101       work without a need for any other hassle.
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AUTHORS

104       •   Lubomir Rintel <lkundrak@v3.sk>
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106       •   Collin R. Mulliner <collin@betaversion.net>
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108           <http://www.mulliner.org/bluetooth/>
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110           Parts of code were taken from were taken from xkbd-bthid project.
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112       btkbdd can be redistributed under the same terms and conditions as
113       xkbd-bthid itself: GNU General Public License (any version at your
114       option).
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116       The source code repository can be obtained from
117       <https://github.com/lkundrak/virtkbd>. Bug fixes and feature
118       ehancements licensed under same conditions as btkbdd  are welcome via
119       GIT pull requests.
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