Bluetooth Blues

Question

I've discovered again that cursing and swearing at inanimate objects doesn't actually improve things, so I'll try posting a question.

A couple of months ago I attempted a fairly ambitious project (Sonos Bluetooth Bridge) with my RPi that didn't work out. It was a fairly complex project IMHO, and as the author of the article didn't respond to help requests, I decided to set it aside, and start with a simpler Bluetooth project.

Connecting to a Bluetooth speaker seemed straightforward enough, but I'm now wondering if there is such a thing as a simple Bluetooth project. My setup is simple:

Raspberry Pi 3B+ w/ current Raspbian stretch
Anker SoundCore mini speaker

Just to verify the speaker worked, in about 2 minutes I was able to connected from my phone & play music. Speaker works.

Here's an attempt to show the relevant software on my system:

$ dpkg -l | grep blue
ii  bluez                             5.43-2+rpt2+deb9u2                armhf        Bluetooth tools and daemons
ii  bluez-firmware                    1.2-3+rpt7                        all          Firmware for Bluetooth devices
ii  pi-bluetooth                      0.1.10                            all          Raspberry Pi 3 bluetooth
ii  pulseaudio-module-bluetooth       10.0-1+deb9u1                     armhf        Bluetooth module for PulseAudio sound server

From my RPi, I used bluetoothctl to discover and pair with the speaker as follows (some steps deleted for brevity):

pi@raspberrypi3b:~ $ sudo bluetoothctl
[NEW] Controller B8:27:EB:67:85:55 raspberrypi3b [default]
[NEW] Device F4:4E:FD:2A:3C:B6 SoundCore mini
[NEW] Device A8:66:7F:4D:1A:B2 SdMiPhone 
[bluetooth]# info F4:4E:FD:2A:3C:B6
Device F4:4E:FD:2A:3C:B6
    Name: SoundCore mini
    Alias: SoundCore mini
    Class: 0x240404
    Icon: audio-card
    Paired: yes
    Trusted: yes
    Blocked: no
    Connected: no
    LegacyPairing: no
    UUID: Audio Sink                (0000110b-0000-1000-8000-00805f9b34fb)
    UUID: A/V Remote Control Target (0000110c-0000-1000-8000-00805f9b34fb)
    UUID: A/V Remote Control        (0000110e-0000-1000-8000-00805f9b34fb)
    UUID: Handsfree                 (0000111e-0000-1000-8000-00805f9b34fb)
[bluetooth]# connect F4:4E:FD:2A:3C:B6
Attempting to connect to F4:4E:FD:2A:3C:B6
Failed to connect: org.bluez.Error.Failed

Research on the error led to zillions of matches, but the most promising appeared to a couple of answers given here on SE - @udjamaflip answer for Raspberry Pi. This answer refers to another answer on the SE Ubuntu site.. And one other answer on Unix&Linux SE.

I think I've followed the steps correctly. I've edited both files IAW the referenced answer, rebooted, used pactl, but I still get the failure:
Failed to connect: org.bluez.Error.Failed

FWIW, the pactl step succeeds once per reboot, trying to load-module again gets an error, but it can be unload-ed, and then load-ed successfully:

$ pactl load-module module-bluetooth-discover
20
$ pactl load-module module-bluetooth-discover
Failure: Module initialization failed 
$ pactl unload-module module-bluetooth-discover
$ pactl load-module module-bluetooth-discover
22
$

The syslog shows the following for each attempt at a connection w/ bluetoothctl:

bluetoothd[491]: a2dp-sink profile connect failed for F4:4E:FD:2A:3C:B6: Protocol not available

Any ideas or suggestions are much appreciated.

ICYI, a follow-up question was asked in August, 2020, and an answer was found shortly thereafter; see Bluetooth Blues, Redux — Seamus, Sep 18 '20 at 23:20

score 1 · Answer 1 · answered Oct 07 '19 at 10:49

1

A possible solution is to add users to groups e.g.

sudo gpasswd -a pi pulse
sudo gpasswd -a pi lp
sudo gpasswd -a pulse lp
sudo gpasswd -a pi audio
sudo gpasswd -a pulse audio

answered Oct 07 '19 at 10:49

Jim

11
1

3

How on Earth would adding the user to the lp group help with bluetooth audio? – Dmitry Grigoryev Oct 07 '19 at 10:59
1

@DmitryGrigoryev I'm no expert and this is just a suggestion to try, but an explanation might be that by default the bluetooth daemon will only give out devices to users that are a member of the lp group. – Jim Oct 07 '19 at 12:21
1

lp stand for "line printer", and I'm yet to find out why the bluetooth daemon would care about that group at all. If you want to give a user every permission there is just in case, just switch to root user. – Dmitry Grigoryev Oct 07 '19 at 12:37
1

See note near the beginning of https://wiki.archlinux.org/index.php/bluetooth#Using_your_computer.27s_speakers_as_a_bluetooth_headset – Jim Oct 07 '19 at 13:57
1

Also discussion in "Pairing works, but connecting does not" of https://wiki.archlinux.org/index.php/Bluetooth_headset – Jim Oct 07 '19 at 14:20

Bluetooth Blues

1 Answers1

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