SOLVED: Cannot automatically pair a Bluetooth device on MGA3

[jaywalker]

[EDIT: The short answer is YES; MGA3 will do automatic pairing of Bluetooth 2.1 compliant devices.]

First, a disclaimer; I have never been able to get any new Bluetooth device connected in less than an hour.

This one has had me beaten for five days so far, but that is not a record.

The device is an anonymous little black box designed to accept any line-level audio source as input and send it over Bluetooth link to ... a "compatible" Bluetooth receiver. It does have a mini B type USB socket, but that is only used for charging the internal 3.7v lithium battery. The only other socket is a 1/8 inch stereo jack and the sole control is the on-off switch.

According to the rather terse (a rough translation from the original Klingon, I suspect) "manual" which comes with the transmitter device it is only neccessary to turn it on and wait for the flashing red and blue LEDs to settle down to blue only which indicates it is successfully paired. This never happens, and certainly not in the 10 seconds the manual suggests might be necessary.

What I have been able to discover, but not yet able to confirm, it may be Bluetooth 2.1 device. I infer this from the fact that automatic pairing without user intervention is apparently implemented only in version 2.1 of the Bluetooth spec. I have no idea whether this means I need special Bluetooth receivers or a particular version of the linux Bluetooth system, or both. I have tried 3 different Bluetooth receiver devices without success.

I suppose I really only have one question which stands a chance of someone in our small community having an answer; does Mageia 3 "do" automatic pairing of Bluetooth devices?

Richard

[jaywalker]

I have now found confirmation of some of my guesses. Yes, it is a Bluetooth 2.1 device so it must be depending on automatic pairing. That just leaves the question of whether the Bluetooth stack in Mageia 3 knows what Bluetooth 2.1 is. If nobody here knows for sure I reckon I'll just have to use the source. I reckon that means downloading the kernel source tree so I'll start that now.

Richard

[doktor5000]

That just leaves the question of whether the Bluetooth stack in Mageia 3 knows what Bluetooth 2.1 is.

FWIW, bluez supports up to bluetooth 4.0 since more then a year.
Check http://www.bluez.org/profiles/ and the more up-to-date list: http://git.kernel.org/cgit/bluetooth/bl ... xt?id=HEAD

For the pairing, check http://stackoverflow.com/questions/1288 ... ithout-pin
and for some more information https://wiki.archlinux.org/index.php/bluetooth

[jaywalker]

Thanks Dok, I am far from fluent in Bluetooth so many or most of the terms are confusing or just opaque. What I have gleaned from the referenced pairing articles is that Bluez4 implies support for Bluetooth protocols/revisions upto and including 4.0. I am still looking for confirmation that these various incarnations of Bluetooth must be supported by hardware as well as software. I am inclined to believe this is the case having read somewhere that Bluetooth 2.1 required a specific capability in the chipset which may or may not be supported by the accompanying firmware, or maybe that was software. Given that Bluetooth 2.1 has been a theoretical reality (?) for six or seven years it seems highly probable that any driver support which may or may not be needed is available in current MGA3 kernels. Ditto, I suppose, for the user space stuff.

So given that the software in MGA3 is probably up to the task, my failure to get the device to work may be explained by EITHER; the three USB BT dongles I have tried are not capable of handling BT2.1 auto-pairing and thus cannot be any "better" than BT2.0, OR there is no such thing as plug'n'play in the BT world.

The two articles you pointed me to, insofar as I could understand any of it, suggest that at a minimum I will have to study for my Bluetooth masters degree and then I will be able to deduce what particular incantation should be included in which configuration file for one or more of several daemons. Piece of cake. It is sad that there is such a huge gap separating the vocabulary I would use too describe my hardware and its capabilities and my needs and that which is found in all of the Bluetooth discussions I have come across.

I still don't know, and cannot figure out, if my audio transmitter hardware is an HDID device with VLSA capabilities needing a user to be put in the rt group and rules to be written or unwritten for daemons or wizards, but I will find out, and if we are all still alive when I do, I will report back here with details of my journey to success.

R

[jaywalker]

Watch this space...

I'm not sure what I did or even when it started to be usable, but I have been listening to TV sound through the transmitter for about half an hour. I'll try to retrace my steps tomorrow to find out what it was that did the trick, but I am fairly confident that only one of the three BT dongles I bought in the last few years can do the job.

R

[doktor5000]

I am still looking for confirmation that these various incarnations of Bluetooth must be supported by hardware as well as software. I am inclined to believe this is the case having read somewhere that Bluetooth 2.1 required a specific capability in the chipset which may or may not be supported by the accompanying firmware, or maybe that was software. [...] Ditto, I suppose, for the user space stuff.

Yes, both hardware (sender/receiver and dongle) and userspace must support the profile. So if your dongle doesn't support 2.1, you would be out of luck.
You should at least include lspcidrake -v or lsusb output for each of the dongles, otherwise nobody can provide more help then guesswork.

You can also query the information

Code: Select all

[doktor5000@Mageia4 ~]$ bluetoothctl
[NEW] Controller 0C:60:76:FA:2B:45 localhost-0 [default]
[NEW] Device E8:BB:A8:3D:85:E2 Oppo N1
[NEW] Device 00:23:76:E6:6D:18 NexusHD2
[bluetooth]# show
Controller 0C:60:76:FA:2B:45
        Name: Mageia4
        Alias: localhost-0
        Class: 0x1c010c
        Powered: yes
        Discoverable: no
        Pairable: yes
        UUID: PnP Information           (00001200-0000-1000-8000-00805f9b34fb)
        UUID: Generic Access Profile    (00001800-0000-1000-8000-00805f9b34fb)
        UUID: Generic Attribute Profile (00001801-0000-1000-8000-00805f9b34fb)
        UUID: A/V Remote Control        (0000110e-0000-1000-8000-00805f9b34fb)
        UUID: A/V Remote Control Target (0000110c-0000-1000-8000-00805f9b34fb)
        UUID: Audio Source              (0000110a-0000-1000-8000-00805f9b34fb)
        UUID: Audio Sink                (0000110b-0000-1000-8000-00805f9b34fb)
        UUID: Phonebook Access Server   (0000112f-0000-1000-8000-00805f9b34fb)
        UUID: OBEX File Transfer        (00001106-0000-1000-8000-00805f9b34fb)
        UUID: OBEX Object Push          (00001105-0000-1000-8000-00805f9b34fb)
        Modalias: usb:v1D6Bp0246d050B
        Discovering: no

The two articles you pointed me to, insofar as I could understand any of it, suggest that at a minimum I will have to study for my Bluetooth masters degree and then I will be able to deduce what particular incantation should be included in which configuration file for one or more of several daemons.

Usually, for bluetooth headsets or similar, you should be able to pair them via the bluetooth applets, and simply route sound to them via your desktop mixer.
You don't need a master degree - you're maybe overthinking this.

[jaywalker]

Yes, both hardware (sender/receiver and dongle) and userspace must support the profile. So if your dongle doesn't support 2.1, you would be out of luck.
You should at least include lspcidrake -v or lsusb output for each of the dongles, otherwise nobody can provide more help then guesswork.

Yes, of course a complete investigation would likely have lead to my submission of the information you describe. The original question, being limited in its scope, should, and as it turned out, did have an answer independent of specific knowledge of specific hardware; yes, MGA3 can do automatic pairing of Bluetooth devices given that the hardware at both ends will support it.

Interestingly, just to take a brief diversion, you suggest using a diagnostic tool which I have seen suggested by others in various other Bluetooth-related discussions; bluetoothctl. I have hunted the MGA3 repositories for this tool and can find it nowhere. It's sad, really, because from the look of the example output you provided it might have proved very useful in identifying the capabilities of the three dongles I have tried.

Usually, for bluetooth headsets or similar, you should be able to pair them via the bluetooth applets, and simply route sound to them via your desktop mixer.
You don't need a master degree - you're maybe overthinking this.

Ah, there speaks a man who is completely comfortable in his mastery of the arcane. Sadly I have close to zero familiarity with Bluetooth kit and I have a drawer full non-functioning bits and pieces to prove it :~) I have no reason to doubt what you say about Bluetooth headsets but since we are talking about a device which we now know is capable of pairing automatically without assistance from any applet, and as the device in question functions not as a receiver of audio from the computer but as a source seen by the computer as an input signal, it is not a particularly good comparison.

The problem I face now is to discover exactly what it was that I did which made it all work last week. I have spent a couple of nights stripping components from the system and putting them back one at a time to see if I can spot the tell-tale signs in the system log that I am making progress. It sounded like a logical plan, but it has thrown up more questions than answers. I thought I would only have to re-introduce the minor changes I had to make to /etc/bluetooth/audio.conf to spot the success in the log and know what was working. I took plenty of notes but that's not how it turned out, I now have another investigation of another question which, if it belongs anywhere, it is in another thread. This one is solved.

Thankyou for the pointer to the Archlinux discussions. Together with my own searches it is clear that there are more people who struggle with Bluetooth than who understand it.

Richard

[doktor5000]

Interestingly, just to take a brief diversion, you suggest using a diagnostic tool which I have seen suggested by others in various other Bluetooth-related discussions; bluetoothctl. I have hunted the MGA3 repositories for this tool and can find it nowhere.

Well, it's contained in the bluez package itself, so should already be installed. Not sure how you searched, but the obvious shows:

Code: Select all

[doktor5000@Mageia4 ~]$ urpmf bluetoothctl                                                                                                                             
bluez:/usr/bin/bluetoothctl
bluez:/usr/bin/bluetoothctl
[doktor5000@Mageia4 ~]$

But it may be missing in mga3. You can still use the "legacy" tools hciconfig and hcitool.

[jaywalker]

Yes Dok, tried your "urpmf bluetoothctl" and got nothing that way either. I suppose that urpmf command does the same job as searching for a string in filenames using rpmdrake, as that is what I usualy do to find a package I need.

But now that I have discovered that autopairing works and which dongle I have to use to do it, I am turning my attention to what other unadvertised software is necessary to have installed so that autopairng works with my A2DP (? I think) device.

I am on leave at the moment and in theory I should have more time to do this, but at the moment I am working on the guitar with which I hope to use the device; lots of body-work and lots of re-wiring, but it's fun.

R