rpi 3B and Logitech k400

1st Official Post

    Hello,

    My k400 keyboard works after a fashion with kodi install on rpi 3b, but more often than not I need to turn the keyboard off and on again, (several times) to get kodi to respond, as if the receiver goes into some kind of hibernation / sleep mode that keyboards button press or mouse action doesn't 'wake'. I've spent an hour or so on google looking to see if this has been previously reported but did not find anything that looked like would solve this issue (which makes me suspicious it is something else about my setup, HDMI is only other connection (other than power)).

    Any ideas would be appreciated.

    Regards,

    PiPPiP

    I'm using two K400 (original version) on various RPis (0-4) with and without a USB hub in between since several years and haven't seen such an issue yet.

    Are you sure the batteries are fine? They last almost forever but after about 5 years I had to replace them on my very first K400.

    Edit: also check with `vcgencmd get_throttled` after you experienced the issue if you get anything else than 0x0 - marginal power supplies and undervoltage conditions are known to upset a lot of USB devices.

    so long,

    Hias

    • Official Post

    I too have a K400 on my Rpi 1/2/3 & 4 working without any issues.

    As @HiassofT mentioned change the batteries.

    I would also check that there is not too much "metal" or other stuff in the way of the receiver and the keyboard.

    If still no joy post the URL output of

    dmesg | paste

    and

    lsusb | paste

    thanks both,


    I've not yet done either of the above - apologies only just got back to the forum tonight, and have run out of steam.

    Am a novice, are the above command to be run from tty session? Any particular directory I need to run it from?

    Regards,

    PiPPiP

    The interesting line in your dmesg is this one, 2 minutes after system startup:

    Code
    [ 121.582064] logitech-hidpp-device 0003:046D:400E.0004: HID++ 2.0 device connected.

    I can get this on my RPi4, too, when I switch the keyboard off and then back on.

    So it very much looks like the Logitech unifying receiver lost the connection to your keyboard and then reconnects. This can be for a number of reasons - RF interference, keyboard switched off/on, keyboard too far away from receiver or receiver shielded by some metal etc.

    Not much we can do about it, you have to check for these things in your setup.

    BTW: A couple of years ago I had connection issues with the unifying receiver plugged directly into one of the back USB ports of my PC (with metal case). Using the ~5cm adapter that shipped with it was enough to cure these. Problem in this case was the metal case shielded the receiver. So if in doubt always use the adapter.

    so long,

    Hias

    If you stuck your RPi somewhere in the back of your TV/shelf/... try connecting the receiver with a ~1m USB extension cable and place it somewhere in the front of the TV - so there's nothing (metal) between the keyboard and the receiver that might block RF.

    so long,

    Hias