Audio on Linux systems has always been rather complicated. ALSA (Advanced Linux Sound Architecture) is advanced indeed and thus even simple setups are complicated.
Bluetooth adds another level of complexity. And therefore the forums are full of posts asking for help on how to connect a Linux system with a bluetooth speaker or headset. This is no different with Raspbian.
Until Raspbian-Jessie, for bluetooth-devices you additionally needed PulseAudio, making things even more complicated. With Stretch this has changed and PulseAudio was replaced with a rather simple helper daemon called bluealsa. Nevertheless, a simple setup is still complicated, partly because the maintainer of the bluealsa package installs the daemon only for grafical environments.
This project tries to simplify the setup of bluetooth-audio. Idealy, all you need to do is to replace a single MAC-address (of you bluetooth-device) in a single configuration file. There is one caveat though: the project currently only supports a single device, but anyhow, this should already cover most of the use-cases.
To use bluealsa, you first have to manually pair the Pi with your device
and establish a trust. This is done using the program bluetoothctl. The
following screenshot shows all the necessary steps:
.
You don't have to type all these numbers, just type the first few and then press the TAB key for autocompletion.
After pairing, note down the MAC address of your bluetooth-device, you will need it later for configuring ALSA.
To install all necessary software and the template configuration files, run the following commands:
git clone https://github.com/bablokb/pi-btaudio.git
cd pi-btaudio
sudo tools/install
The install script will
- create the
/etc/systemd/system/bluealsa.service, which will start the bluealsa-daemon even on headless systems - create a sample
/etc/asound.confwhich will make your bluetooth-device the system-wide default audio-device - install a watchdog-daemon which will autoconnect to the bluetooth-device
configured in
/etc/asound.conf. Note that this is not necessary for all bluetooth-devices, but some just don't automatically connect to the Pi. - install the utiliy-scripts
btaudio-connectandbtaudio-disconnectto manually connect and disconnect to the device
After installation, edit the file /etc/asound.conf and insert the MAC
address of your bluetooth-device in the line starting with
defaults.bluealsa.device:
pcm.!default "bluealsa"
ctl.!default "bluealsa"
defaults.bluealsa.interface "hci0"
defaults.bluealsa.device "32:54:03:BB:CC:28"
defaults.bluealsa.profile "a2dp"
That's it for configuration, all scripts and daemons will use this MAC-address.
Now is the time to restart your system. After booting has finished and all daemons are up and running, your Pi should automatically connect to your speaker or headset.