Summary: Everything is connected, and appears to work, but no sound comes out of the speaker - how to diagnose or fix?

I am trying to play sound from my Raspberry Pi 3 to a bluetooth speaker, but it is not working.

The pi connects to the bluetooth speaker (confirmed by automated audio on the speaker when it connects, "raspberrypi connected", and checking echo "info 04:52:C7:5A:3B:A1" | bluetoothctl on the pi also shows it is connected).

The speaker volume is not muted and other devices can connect to it and play through it. Checking alsamixer verifies that audio is not muted.

But using aplay to play sound through the bluetooth speaker leads only to a deafening silence. Although it looks like it works:

$ aplay -D bluealsa:HCI=hci0,DEV=04:52:C7:5A:3B:A1,PROFILE=a2dp /usr/share/sounds/alsa/Front_Center.wav
Playing WAVE '/usr/share/sounds/alsa/Front_Center.wav' : Signed 16 bit Little Endian, Rate 48000 Hz, Mono

I have looked for log files that might have information in them, but haven't found anything.

bluealsa configuration

I set this up following the instructions here. The details of this set up are:

• Raspbian Stretch, 2018-10-09 image (bluealsa v5.43 installed out of box)


• bluez v5.49 downloaded, built and installed (no errors)


• 
  /etc/dbus-1/system.d/bluetooth.conf edited, following lines added to root element:
  
  
  • <allow send_interface="org.bluez.ThermometerWatcher1"/>
  
  
  • <allow send_interface="org.bluez.HeartRateWatcher1"/>
  
  
  • <allow send_interface="org.bluez.CyclingSpeedWatcher1"/>
  
  


• And following also added to the top level busconfig element:
  
  
  • <policy group="bluetooth"><allow send_destination="org.bluez"/></policy>
  
  


• pi user added to bluetooth group

I have tried moving the HCI, device and profile details into .asoundrc and /etc/asound.conf files but these produce the same results (console output suggests successful, but no sound comes from the speaker when I use aplay).

Other things (probably not relevant but including for completeness)

• pi access is via SSH (it's headless)


• on booting the pi, sudo systemctl status blueto* shows an error message on the bluetooth service: Failed to set privacy: Rejected (0x0b), apparently a boot-related issue (link) which is fixed by manually restarting the bluetooth service after boot using systemctl (ugly, but fine as a workaround for now)


• no suspicious looking messages in dmesg, user.log or boot.log


• but the following was in daemon.log, it correlates with an execution of the aplay command above (but I have tried that command several times with the same console output, it generates them sometimes only):

.

Nov 10 21:02:16 rpi_3e5ccf bluealsa[789]: /usr/bin/bluealsa: Unsupported AT message: SET: command:+CLIP, value:1
Nov 10 21:02:16 rpi_3e5ccf bluealsa[789]: /usr/bin/bluealsa: Unsupported AT message: CMD: command:+CLCC, value:(null)
Nov 10 21:02:16 rpi_3e5ccf bluealsa[789]: /usr/bin/bluealsa: Unsupported AT message: SET: command:+CSRSF, value:0,0,0,1,0,0,0

Ultimately I was unable to debug this and got impatient, so just wiped the SD and started from scratch. The detailed steps I followed are below, these mean I can now play audio using aplay without having to specify the device, e.g.:

aplay /usr/share/sound/alsa/Front_Center.wav

1) Set up SD card image

• use etcher to burn 2018-10-09-raspbian-stretch.img


• touch /boot/ssh


• add a suitable /boot/wpa_supplicant.conf file


• edit /rootfs/etc/hostname

2) ssh-copy-id from host to pi, for convenient SSH

3) Set up software on the pi:

• passwd


• sudo apt update; sudo apt dist-upgrade


• sudo apt install vim git screen htop rpi-update


• sudo apt autoremove


• sudo systemctl set-default multi-user.target # don't start X windows on boot


• sudo BRANCH=next rpi-update


• sudo reboot

4) Update bluez

• sudo apt install libdbus-1-dev libglib2.0-dev libudev-dev libical-dev libreadline-dev


• 
  wget http://www.kernel.org/pub/linux/bluetooth/bluez-5.50.tar.xz
  tar -xf bluez-5.50.tar.xz`


• cd bluez-5.50/


• ./configure --prefix=/usr --mandir=/usr/share/man --sysconfdir=/etc --localstatedir=/var --enable-experimental


• make -j4


• sudo make install


• 
  sudo cp /etc/dbus-1/system.d/bluetooth.conf /etc/dbus-1/system.d/bluetooth.conf.bak, then edit:
  
  
  • add to root: <allow send_interface="org.bluez.ThermometerWatcher1"/><allow send_interface="org.bluez.HeartRateWatcher1"/><allow send_interface="org.bluez.CyclingSpeedWatcher1"/>
    
  
  
  • add new child of busconfig: <policy group="bluetooth"><allow send_destination="org.bluez"/></policy>
    
  
  

5) Get bluetooth working

• sudo adduser pi bluetooth


• sudo reboot


• bluetoothctl: scan on
  


• bluetoothctl: trust 04:52:C7:5A:3B:A1
  


• bluetoothctl: connect 04:52:C7:5A:3B:A1
  


• aplay -D bluealsa:HCI=hci0,DEV=04:52:C7:5A:3B:A1,PROFILE=a2dp /usr/share/sounds/alsa/Front_Center.wav # test it works at all

6) Get bluetooth working without specifying the device by creating the following /etc/asound.conf file:

pcm.bose 
 type plug
 slave 
 pcm 
 type bluealsa
 interface hci0
 device 04:52:C7:5A:3B:A1
 profile "a2dp"
 
 
 hint 
 show on
 description "Bose speaker"
 

pcm.!default 
 type plug
 slave.pcm "bose"

ctl.!default 
 type hw
 card 0

For reference and credit, this is based on information from the following three sources:

• link


• link


• link

And in reply to @Parthiban's comment above, here is the dbus-monitor output from the now-working system:

signal time=1541964336.104905 sender=org.freedesktop.DBus -> destination=:1.1 serial=2 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameAcquired
 string ":1.1"
signal time=1541964336.105032 sender=org.freedesktop.DBus -> destination=:1.1 serial=4 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameLost
 string ":1.1"
method call time=1541964336.106756 sender=:1.0 -> destination=org.freedesktop.DBus serial=3 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=RequestName
 string "org.freedesktop.systemd1"
 uint32 7
signal time=1541964336.106880 sender=org.freedesktop.DBus -> destination=(null destination) serial=5 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameOwnerChanged
 string "org.freedesktop.systemd1"
 string ""
 string ":1.0"
signal time=1541964336.107024 sender=org.freedesktop.DBus -> destination=:1.0 serial=4 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameAcquired
 string "org.freedesktop.systemd1"
method return time=1541964336.107096 sender=org.freedesktop.DBus -> destination=:1.0 serial=5 reply_serial=3
 uint32 1
method call time=1541964336.108116 sender=:1.0 -> destination=org.freedesktop.DBus serial=4 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=ListNames
method return time=1541964336.108179 sender=org.freedesktop.DBus -> destination=:1.0 serial=6 reply_serial=4
 array [
 string "org.freedesktop.DBus"
 string "org.freedesktop.systemd1"
 string ":1.0"
 ]