Periodic dropouts for Logitech Unifying Receiver

schmidtbag · 2023-07-10 13:40:43

I have a wireless keyboard and mouse by Logitech, connected to the same Unifying Receiver. I've been having issues where sometimes, one of the devices will loose connection for a few seconds, and re-connect. I will experience one of the devices disconnecting maybe once per hour on average, though the keyboard seems more prone to disconnecting. Since the issue is seemingly random and only affects one device at a time, I think I can rule out that the USB port or receiver are defective. Any ideas on how to solve this?

Here's what I can tell you and what I've tried:
* They are roughly 2m away from the receiver and almost have line of sight, where maybe my knee might get in the way.
* I've swapped USB ports and even swapped the Unifying Receiver.
* Batteries for both are relatively new; one is over 70%, the other is 90%.
* My router supports both 2.4GHz and 5GHz bands, but most of my devices are only connected to 5GHz. Even if my idle phone is the only device connected, I still get this problem. The PC that the keyboard/mouse are connected to is wired.
* I do have a Bluetooth adapter right next to it, but this problem still happens even if there are no BT devices connected.
* Whether the computer is mostly idle or under heavy load, I still encounter the problem.

It seems that on Windows, one way to solve the problem is to change the power profile, but I'm not sure how to do this on Linux, if you even can.

Last edited by schmidtbag (2023-07-10 13:44:07)

V1del · 2023-07-10 15:06:05

Try disabling USB autosuspension for the receiver: https://wiki.archlinux.org/title/Power_ … utosuspend

seth · 2023-07-10 15:24:42

where maybe my knee might get in the way

Is it a bionic knee?

https://wiki.archlinux.org/title/Power_ … utosuspend
The theory would be that the receiver suspends, one of the devices notices it, re-pairs, that wakes the receiver and the other device takes benefit and just continues it connection, unaware of the interim loss.

F5**

Last edited by seth (2023-07-10 15:25:01)

schmidtbag · 2023-07-10 22:17:52

Seems disabling autosuspension hasn't made any difference.
Any other suggestions?

EDIT:
Out of curiosity, I tried unplugging the Bluetooth adapter, which I think has worked. I don't really see why it should matter, when there were no devices connected, but I went a good hour or two without any interruptions, which is the longest I can recall. Not sure what to do about this though, because I do use BT for some things.

Last edited by schmidtbag (2023-07-11 03:06:02)

seth · 2023-07-11 06:07:21

I've swapped USB ports and even swapped the Unifying Receiver.

Can you get the BT and UR dongles onto opposing sides of the case?
Can the logitech devices run in BT mode?
Is it sufficient to simply rfkill BT?

this problem still happens even if there are no BT devices connected

Do you use a more fancy BT/WIFI control (networkmanager) that runs periodic scans for no reason but to pollute the radioband?

schmidtbag · 2023-07-11 23:45:28

seth wrote:

Can you get the BT and UR dongles onto opposing sides of the case?

That seems to help a little, but not fix the problem.

Can the logitech devices run in BT mode?

I think so, but I deliberately don't do that due to a handful of minor gripes I have with BT.

Is it sufficient to simply rfkill BT?

If I'm not using it, sure. But there will be times I use both.

Do you use a more fancy BT/WIFI control (networkmanager) that runs periodic scans for no reason but to pollute the radioband?

As far as I can tell, no. That is something I looked for.

seth · 2023-07-12 06:24:34

a handful of minor gripes I have with BT

Like breaking your input devices

Do you have a different BT dongle?
It certainly sounds like interference.

d_fajardo · 2023-07-12 07:10:59

@schmidtbag Is Solaar installed by any chance? I ask because it automatically creates udev rules to manage the unifying receiver. I don't think the receiver works as a BT device but probably you're BT and receiver are sharing the same bus.

c00ter · 2023-07-12 12:59:29

How much does the 2m distance impact this?

schmidtbag · 2023-07-13 02:58:29

d_fajardo wrote:

@schmidtbag Is Solaar installed by any chance? I ask because it automatically creates udev rules to manage the unifying receiver. I don't think the receiver works as a BT device but probably you're BT and receiver are sharing the same bus.

I am using solaar but I don't see any udev rules created by it anywhere in /etc/udev.

c00ter wrote:

How much does the 2m distance impact this?

Not sure - that's why I pointed it out, in case someone felt that was too far. According to Logitech, it should be able to go to 10m.

seth · 2023-07-13 05:01:18

/usr/share/solaar/udev-rules.d/42-logitech-unify-permissions.rules - but that sounds like it's just getting certain users/groups access to the device.

The unifying receiver is essentially a proprietary bluetooth, it actually uses bluetooth hardware but implements logitechs similar-and-almost-but-not bluetooth knock-off on them.
Therefore the same NFC limitations apply (and 2m line of sight is not an issue at all) but it also uses the same frequency range in very similar patterns.

Since rfkill'ing your BT stabilizes the UR, interference is then the by far most likely cause.
- try a different BT dongle (if you have one)
- try different channels on the UR
- use your input devices via BT

schmidtbag · 2023-07-14 22:38:27

seth wrote:

The unifying receiver is essentially a proprietary bluetooth, it actually uses bluetooth hardware but implements logitechs similar-and-almost-but-not bluetooth knock-off on them.
Therefore the same NFC limitations apply (and 2m line of sight is not an issue at all) but it also uses the same frequency range in very similar patterns.
Since rfkill'ing your BT stabilizes the UR, interference is then the by far most likely cause.
- try a different BT dongle (if you have one)
- try different channels on the UR
- use your input devices via BT

Interesting, didn't know that though I guess I shouldn't be surprised.
I'm totally fine with changing the channels but I haven't found any obvious way to do so. None of the graphical tools I have for either UR or BT seem to have a way to do this, anyway.

seth · 2023-07-15 05:49:02

Cause some BT traffic (music over BT headphones?) and switch the logitech devices off and on again to force a re-pairing against the BT noise.

Arch Linux

#1 2023-07-10 13:40:43

Periodic dropouts for Logitech Unifying Receiver

#2 2023-07-10 15:06:05

Re: Periodic dropouts for Logitech Unifying Receiver

#3 2023-07-10 15:24:42

Re: Periodic dropouts for Logitech Unifying Receiver

#4 2023-07-10 22:17:52

Re: Periodic dropouts for Logitech Unifying Receiver

#5 2023-07-11 06:07:21

Re: Periodic dropouts for Logitech Unifying Receiver

#6 2023-07-11 23:45:28

Re: Periodic dropouts for Logitech Unifying Receiver

#7 2023-07-12 06:24:34

Re: Periodic dropouts for Logitech Unifying Receiver

#8 2023-07-12 07:10:59

Re: Periodic dropouts for Logitech Unifying Receiver

#9 2023-07-12 12:59:29

Re: Periodic dropouts for Logitech Unifying Receiver

#10 2023-07-13 02:58:29

Re: Periodic dropouts for Logitech Unifying Receiver

#11 2023-07-13 05:01:18

Re: Periodic dropouts for Logitech Unifying Receiver

#12 2023-07-14 22:38:27

Re: Periodic dropouts for Logitech Unifying Receiver

#13 2023-07-15 05:49:02

Re: Periodic dropouts for Logitech Unifying Receiver

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