Flakey Bluetooth Devices

[Jonathan Ryshpan]

There are two bluetooth devices paired with my main computer.  The
connection is via this dongle:
   $ lsusb
   ...
   Bus 003 Device 003: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)
Two devices are paired:
   $ bluetoothctl paired-devices
   Device C0:15:DA:B9:77:39 Bluetooth Ergonomic Mouse
   Device 3B:0C:40:C7:35:16 TEWELL T-1
Both have problems:

The MS Ergonomic Mouse often doesn't connect when the system starts.
 Sometimes it's possible to get it to connect by running
   $ bluetoothctl connect C0:15:DA:B9:77:39
but generally the only way to get the it to connect is by running:
   $ sudo pkill bluetoothd
which kills the bluetooth daemon; another instance is automatically
restarted, which recognizes the mouse.
Also, the mouse often falls asleep; it's possible to wake it by moving
it around, but it would be nicer is it stayed awake.

$ bluetoothctl info C0:15:DA:B9:77:39
Device C0:15:DA:B9:77:39 (random)
        Name: Bluetooth Ergonomic Mouse
        Alias: Bluetooth Ergonomic Mouse
        Appearance: 0x03c2
        Icon: input-mouse
        Paired: yes
        Trusted: yes
        Blocked: no
        Connected: yes
        WakeAllowed: yes
        LegacyPairing: no
        UUID: Generic Access Profile    (00001800-0000-1000-8000-00805f9b34fb)
        UUID: Generic Attribute Profile (00001801-0000-1000-8000-00805f9b34fb)
        UUID: Device Information        (0000180a-0000-1000-8000-00805f9b34fb)
        UUID: Battery Service           (0000180f-0000-1000-8000-00805f9b34fb)
        UUID: Human Interface Device    (00001812-0000-1000-8000-00805f9b34fb)
        UUID: Vendor specific           (7a440b82-7fc2-45bd-83e6-d6d78c5669d1)
        Modalias: usb:v045Ep0834d0124
        Battery Percentage: 0x64 (100)

The TEWELL internet radio often cuts off the first part of sentences
when listening to voice.  I can post a recording if anyone wants to
hear.

$ bluetoothctl info 3B:0C:40:C7:35:16
   Device 3B:0C:40:C7:35:16 (public)
          Name: TEWELL T-1
          Alias: TEWELL T-1
          Class: 0x00340404
          Icon: audio-headset
          Paired: yes
          Trusted: yes
          Blocked: no
          Connected: yes
          LegacyPairing: no
          UUID: Audio Sink                (0000110b-0000-1000-8000-
   00805f9b34fb)
          UUID: A/V Remote Control Target (0000110c-0000-1000-8000-
   00805f9b34fb)
          UUID: Advanced Audio Distribu.. (0000110d-0000-1000-8000-
   00805f9b34fb)
          UUID: A/V Remote Control        (0000110e-0000-1000-8000-
   00805f9b34fb)
          UUID: PnP Information           (00001200-0000-1000-8000-
   00805f9b34fb)
          Modalias: bluetooth:v05D6p000Ad0240

System Info:

Operating System: Fedora Linux 35
   KDE Plasma Version: 5.23.5
   KDE Frameworks Version: 5.90.0
   Qt Version: 5.15.2
   Kernel Version: 5.16.5-200.fc35.x86_64 (64-bit)
   Graphics Platform: X11
   Processors: 8 × Intel® Core™ i7-4790K CPU @ 4.00GHz
   Memory: 15.5 GiB of RAM
   Graphics Processor: Mesa Intel® HD Graphics 4600

[Tom Horsley]

On Wed, 09 Feb 2022 10:32:30 -0800
Jonathan Ryshpan wrote:

I've never had any bluetooth device reliably connecting to anything
(linux, windows, my car's audio, you name it). I've always suspected
that "flakey" was mandated in the bluetooth standard.

[George N. White III]

On Wed, 9 Feb 2022 at 14:49, Tom Horsley  wrote:
> On Wed, 09 Feb 2022 10:32:30 -0800
> Jonathan Ryshpan wrote:
>
> I've never had any bluetooth device reliably connecting to anything
> (linux, windows, my car's audio, you name it). I've always suspected
> that "flakey" was mandated in the bluetooth standard.

Understanding Reliability in Bluetooth® Technology | Bluetooth® Technology
Website
https://www.bluetooth.com/bluetooth-resources/understanding-reliability-in-bluetooth-technology/

I agree that most bluetooth devices are erratic.  Bluetooth reliability is
not easy, but
it _is_ easy to sell "bluetooth" devices that are poorly engineered.

[Jonathan Ryshpan]

On Wed, 2022-02-09 at 13:48 -0500, Tom Horsley wrote:
> On Wed, 09 Feb 2022 10:32:30 -0800 Jonathan Ryshpan wrote:
> There are two bluetooth devices paired with my main computer.  The
> connection is via this dongle:
>    $ lsusb
>    ...
>    Bus 003 Device 003: ID 0a12:0001 Cambridge Silicon Radio, Ltd Bluetooth Dongle (HCI mode)
> Two devices are paired:
>    $ bluetoothctl paired-devices
>    Device C0:15:DA:B9:77:39 Bluetooth Ergonomic Mouse
>    Device 3B:0C:40:C7:35:16 TEWELL T-1
> Both have problems:
>
> I've never had any bluetooth device reliably connecting to anything
> (linux, windows, my car's audio, you name it). I've always suspected
> that "flakey" was mandated in the bluetooth standard.

A lucky Google hit has led me to a cure, which is to create
/etc/udev/rules.d/50-usb_power_save.rules. This disables power saving
to the bluetooth dongle. Read:
   https://askubuntu.com/questions/1303731/how-to-change-bluetooth-timeout-sett...
to find the magic and also links to explanations.