[SOLVED] How to use bluetooth with KDE

Richard Cranium · 08-23-2017, 06:59 PM

When I get home, I'll find the directory where bluetoothd keeps device information. You may have to nuke the contents, which would make all the associations go away.

My guess would be that for some reason, your speakers aren't returning the correct UUIDs that describe what they do. Bluetooth is a really odd protocol. When you connect to a device, you ask it what services it provides. You'll get back a list of UUIDs that are registered with the Bluetooth.com folks that identify the services (such as Human Interface Device or Heart Rate or whatever). You then ask each service what characteristics it has; you'll get back a list of UUIDs that are registered with the same bluetooth folks. (Well, that's for GATT. There's an older way bluetooth worked.)

So maybe bluetoothd knows that your speakers provide the A2DP service (https://www.bluetooth.org/DocMan/han...762.1503532014) but doesn't think that the codec(s) reported by the speakers can be used. Or something. Don't bother to download the A2DP service spec unless you hate yourself. Or love low-level data packet work.

Gordie · 08-23-2017, 08:44 PM

Could it be

Code:

~/.config/bluedevilglobalrc

Richard Cranium · 08-23-2017, 09:44 PM

Quote:

Originally Posted by Gordie

Could it be

Code:

~/.config/bluedevilglobalrc

Actually, no. Well, that might have something in it.

But, what I was talking about was the stuff that bluetoothd knows about; it maintains information about the devices that associated with it.

All that is in /var/lib/bluetooth

For instance, on this machine, I've got a file named

Code:

/var/lib/bluetooth/00:1B:DC:06:A8:BD/00:0D:44:D1:7D:CE/info

which contains

Code:

[General]
Name=H800 Logitech Headset
Class=0x240404
SupportedTechnologies=BR/EDR;
Trusted=false
Blocked=false
Services=0000110b-0000-1000-8000-00805f9b34fb;0000110c-0000-1000-8000-00805f9b34fb;0000110e-0000-1000-8000-00805f9b34fb;0000111e-0000-1000-8000-00805f9b34fb;

[LinkKey]
Key=I_am_sure_that_you_would_like_to_know
Type=4
PINLength=0

(Well, I did change the key value just for you folks.)

This is the MAC address of my bluetooth adapter

Code:

00:1B:DC:06:A8:BD

and this is the MAC address of my headset

Code:

00:0D:44:D1:7D:CE

As it so happens, bluedevil and its cousins talk to bluetoothd via DBUS. My heart rate monitor program uses DBUS to look for, connect to, and register for packets from the monitor on my chest via DBUS.

mfoley · 08-23-2017, 10:03 PM

While this may be irrelevant, I had temporarily paired my BluSplash with my Android. When I un-paired it from the Android and re-paired it with the Slackware/KDE system is when I noticed the gray-out-ness. I can't say for sure it wasn't in that state before pairing with the Android -- just that I didn't notice it then; or don't recall noticing.

My /var/lib/bluetooth contains:

Code:

# ls -R /var/lib/bluetooth/
/var/lib/bluetooth/:                                                                                                                           
5C:F3:70:85:25:54/                                                                                                                             
                                                                                                                                               
/var/lib/bluetooth/5C\:F3\:70\:85\:25\:54:                                                                                                     
FC:58:FA:50:6D:C0/  cache/  settings                                                                                                           
                                                                                                                                               
/var/lib/bluetooth/5C\:F3\:70\:85\:25\:54/FC\:58\:FA\:50\:6D\:C0:                                                                              
info                                                                                                                                           
                                                                                                                                               
/var/lib/bluetooth/5C\:F3\:70\:85\:25\:54/cache:                                                                                               
FC:58:FA:50:6D:C0

5C:F3:70:85:25:54 is the MAC of my BlueZ adapter. FC:58:FA:50:6D:C0 is the MAC of my BluSplash speaker (actually, it shows as 'headset' normally). 'settings' contains:

Code:

# cat /var/lib/bluetooth/5C\:F3\:70\:85\:25\:54/settings 
[General]
Discoverable=true
DiscoverableTimeout=0

'info' contains:

Code:

# cat /var/lib/bluetooth/5C\:F3\:70\:85\:25\:54/FC\:58\:FA\:50\:6D\:C0/info 
[General]
Name=BluSplash
Class=0x260404
SupportedTechnologies=BR/EDR;
Trusted=true
Blocked=false
Services=00001108-0000-1000-8000-00805f9b34fb;0000110b-0000-1000-8000-00805f9b34fb;0000110c-0000-1000-8000-00805f9b34fb;0000110e-0000-1000-8000-00805f9b34fb;0000111e-0000-1000-8000-00805f9b34fb;

[LinkKey]
Key=(like Richard Cranium said ...)
Type=4
PINLength=0

Is any of that meaningful?

What if I just removed the BluSplash device from System Settings > Bluetooth; remove the directory /var/lib/bluetooth/5C:F3:70:85:25:54/FC:58:FA:50:6D:C0/ and re-configured the BluSplash?

Richard Cranium · 08-23-2017, 10:31 PM

Hmm. Your speakers have a service that my headphones don't have.

00001108-0000-1000-8000-00805f9b34fb

That's the HeadSetProfile (https://en.wikipedia.org/wiki/List_o...file_.28HSP.29) (You can find the UUID here https://android.googlesource.com/pla...toothUuid.java)

Quote:

What if I just removed the BluSplash device from System Settings > Bluetooth; remove the directory /var/lib/bluetooth/5C:F3:70:85:25:54/FC:58:FA:50:6D:C0/ and re-configured the BluSplash?

I'd drop down to runlevel 1 when you do the "remove the directory /var/lib/bluetooth/5C:F3:70:85:25:54/FC:58:FA:50:6D:C0/" bit. But, yeah, that's what I'd try.

EDIT: I'd expect the speakers to always report the same set of services to anyone who asked.

mfoley · 08-24-2017, 09:33 AM

Removing and re-adding the device did the trick! Go figure.

Thanks all.