# Logitech Unifying Receiver

The Logitech Unifying Receiver is a wireless receiver that can connect up to six compatible wireless mice and keyboards to your computer. The input device that comes with the receiver is already paired with it and should work out of the box through plug and play. Logitech officially supports pairing of additional devices just through their Windows and macOS software. Pairing on Linux is supported by a small program from Benjamin Tissoires. That tool does not provide any feedback though. Other developers have built more complete pairing tools that give feedback and allow unpairing as well.

ltunify is a command-line C program that can perform pairing, unpairing and listing of devices. Solaar is a graphical Python program that integrates in your system tray and allows you to configure additional features of your input device such as swapping the functionality of Fn keys.

## Installation

Several solutions are available:

- pairing_toolAUR

The following packages use the group plugdev, create the group (if doesn't exists), and add users to this group to avoid the need of running these as root:

- solaarAUR
- ltunify-gitAUR

## Usage

pairingtool can only be used for pairing and does not provide feedback, it also needs to know the device name for pairing. ltunify and Solaar can detect the receiver automatically.

### ltunify

Examples on unpairing a device, pairing a new device and showing a list of all devices:

    $ ltunify unpair mouse
    Device 0x01 Mouse successfully unpaired
    $ ltunify pair
    Please turn your wireless device off and on to start pairing.
    Found new device, id=0x01 Mouse
    $ ltunify list
    Devices count: 1
    Connected devices:
    idx=1   Mouse   M525

### Solaar

Solaar has a GUI and CLI. Example CLI pairing session:

    $ solaar-cli unpair mouse
    Unpaired 1: Wireless Mouse M525 [M525:DAFA335E]
    $ solaar-cli pair
    Pairing: turn your new device on (timing out in 20 seconds).
    Paired device 1: Wireless Mouse M525 [M525:DAFA335E]
    $ solaar-cli show
    -: Unifying Receiver [/dev/hidraw0:08D89AA6] with 1 devices
    1: Wireless Mouse M525 [M525:DAFA335E]

To disable autostart of Solaar, remove `/etc/xdg/autostart/solaar.desktop`.

### pairingtool

To find the device that the receiver has, therefore take a look at the outputs of

    $ ls -l /sys/class/hidraw/hidraw*/device/driver | awk -F/ '/receiver/{print $5}'

This will show the names of your receiver, for example `hidraw0`.

Now switch off the device that you want to pair (if it was on) and execute your compiled program with the appropriate device as argument:

    # pairing_tool /dev/hidraw0
    The receiver is ready to pair a new device.
    Switch your device on to pair it (you have thirty seconds to do so).

Now switch on the device you want to pair. After a few seconds your new device should work properly.

## Known Problems

### Wrong device (pairing tool only)

On some systems there is more than one device that has the same name. In that case you will receive the following error message when the wrong device is choosen:

    # pairing_tool /dev/hidraw1
    Error: 32
    write: Broken pipe

### Keyboard layout via xorg.conf

With kernel 3.2 the Unifying Receiver got its own kernel module hid_logitech_dj which does not work flawlessly together with keyboard layout setting set via xorg.conf. A temporary workaround is to use xorg-setxkbmap and set the layout manually. For example for a German layout with no deadkeys one has to execute:

    $ setxkbmap -layout de -variant nodeadkeys

To automate this process one could add this line to xinitrc or the according autostart file of your windows manager respectively desktop environment.

### Logitech touchpad keyboard K400r with unifying receiver M325

The Logitech keyboard K400r with integrated touchpad comes with Logitech unifying receiver M325 so the above mentioned about the keyboard layout will apply here too.

Also the integrated touchpad is recognized as 'pointer' instead of 'touchpad' so you cannot use the Touchpad Synaptics drivers. Two finger horizontal scrolling and tapclick will work but in order to have a middle mouse button emulated you will have to add

    /etc/X11/xorg.conf.d/10-evdev.conf

    Section "InputClass"
            Identifier "evdev pointer catchall"
            MatchIsPointer "on"
            MatchDevicePath "/dev/input/event*"
            Driver "evdev"
            Option "Emulate3Buttons" "true"
    EndSection

to your evdev.conf. Now third button is emulated by pressing both buttons simultaneously.

### Solaar 'Permission denied'

Is it possible to have the error:

    $ solaar-cli show
    solaar-cli: error: [Errno 13] Permission denied: '/dev/hidraw2'

In this case, you can physically remove the Unifying Receiver and re-insert it, and re-run the command (as described in the second point of installation part on the official site [1]).

### Wireless Keyboard doesn't work while booting (can't enter luks passphrase)

While booting it's impossible to input anything with a Logitech wireless Keyboard (e. g. Logitech MK700). The cause of the problem is the own hid module for Logitech devices since Kernel 3.2.

A workaround is adding hid-logitech-hidpp to MODULES in `/etc/mkinitcpio.conf`:

    MODULES="hid-logitech-hidpp"

and recreate the initrd for the kernel:

    # mkinitcpio -p linux

Category:

- Input devices