Perform Bluetooth A2DP source functions - Qualcomm Dragonwing Documentation

Prerequisites

Before you begin, set up your device and go to the required menu as described in Set up the device for A2DP functions.

Connect a remote device

To connect a remote device in the A2DP source role, run the following command from the bluetoothctl menu:

connect <bt_address>

Parameters <bt_address> is the Bluetooth address of the remote device. Example To connect to a paired remote device with <bt_address> 17:1A:35:8D:A2:A4, run the following command:

connect 17:1A:35:8D:A2:A4

Sample output

[bluetooth]# connect 17:1A:35:8D:A2:A4
Attempting to connect to 17:1A:35:8D:A2:A4
[CHG] Device 17:1A:35:8D:A2:A4 Connected: yes
[CHG] Device 17:1A:35:8D:A2:A4 UUIDs: 0000110b-0000-1000-8000-00805f9b34fb
[CHG] Device 17:1A:35:8D:A2:A4 UUIDs: 0000110c-0000-1000-8000-00805f9b34fb
[CHG] Device 17:1A:35:8D:A2:A4 UUIDs: 0000110e-0000-1000-8000-00805f9b34fb
[CHG] Device 17:1A:35:8D:A2:A4 ServicesResolved: yes
[CHG] Device 17:1A:35:8D:A2:A4 Bonded: yes
[CHG] Device 17:1A:35:8D:A2:A4 Paired: yes
[NEW] Endpoint /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1
[NEW] Endpoint /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep2
[NEW] Transport /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0
Connection successful
[CHG] Transport /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0 State: active
[CHG] Transport /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0 Volume: 0x0040 (64)
[CHG] Transport /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0 State: idle
[CHG] Transport /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0 Volume: 0x0044 (68)
[CHG] Transport /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0 Volume: 0x0040 (64)
[MySoundbar]#

List available transport

To list the available transport, run the following command from the menu transport submenu:

list

Sample output

[MySoundbar]# list
Transport /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0

Get information about codec capabilities

To get the information about the codec capabilities of a transport, run the following command from the menu transport submenu:

show <transport>

Parameters <transport> is the transport path. Example To get the information about the codec capabilities of <transport> /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0, run the following command:

show /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0

Sample output

[MySoundbar]# show /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0
Transport /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0
      UUID: 0000110a-0000-1000-8000-00805f9b34fb
      Codec: 0x00 (0)
      Configuration: 0x21 (33)
      Configuration: 0x15 (21)
      Configuration: 0x02 (2)
      Configuration: 0x35 (53)
      Device: /org/bluez/hci0/dev_17_1A_35_8D_A2_A4
      State: idle
      Volume: 0x0040 (64)

Set absolute volume

Ensure that the DUT and the remote device support the setabsvolume feature.

To set the absolute volume of a transport, run the following command from the menu transport submenu:

volume <transport> [value]

Parameters

<transport> is the transport path.
[value] is the volume level.

Example To set the absolute volume of <transport> /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0 as 50, run the following command:

volume /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0 50

Sample output

[MySoundbar]# volume /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0 50
Changing Volume succeeded
[CHG] Transport /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0 Volume: 0x0032 (50)
[MySoundbar]# volume /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd0 10
Changing Volume succeeded

Play an audio file

The DUT doesn’t support an audio player. Use paplay commands to play music.Only PCM audio sample is supported.

To play songs from the DUT, do the following:

Run SSH.

Play a WAV file by running the following command:

paplay <audio_filepath> -v

Parameters <audio_filepath> is the filepath of the WAV file. Example To play a WAV file at /tmp/playback.wav, run the following command:

paplay /tmp/playback.wav -v

Sample output

sh-5.1# paplay /tmp/playback.wav -v
Opening a playback stream with sample specification 's16le 2ch 44100Hz' and channel map 'front-left,front-right'.
Connection established.
Stream successfully created.
Buffer metrics: maxlength=4194304, tlength=352800, prebuf=349276, minreq=3528
Using sample spec 's16le 2ch 44100Hz', channel map 'front-left,front-right'.
Connected to device bluez_output.17:1A:35:8D:A2:A4 (index: 68, suspended: no).
Stream started.

Get a list of sinks

To get the list of sinks when multiple devices are connected, run the following command in SSH:

pactl list sinks short

The pactl tool isn’t available by default. Enable and build the tool on your device.

Sample output

sh-5.1# pactl list sinks short
51      alsa_output.platform-sound.HiFi__Speaker__sink  PipeWire        s16le 2ch 48000Hz       SUSPENDED
68      bluez_output.17:1A:35:8D:A2:A4  PipeWire        float32le 2ch 48000Hz   SUSPENDED

Play audio on a specific sink

To play audio on a specific sink when multiple devices are connected, run the following command in SSH:

paplay <audio_filepath> --device=<device_name> -v

Parameters

<audio_filepath> is the filepath of the WAV file.
<device_name> is the sink name.

Example To play pcmtest.wav on the bluez_output.17:1A:35:8D:A2:A4 sink, run the following command:

paplay pcmtest.wav --device=bluez_output.17:1A:35:8D:A2:A4 -v

Sample output

sh-5.1# paplay pcmtest.wav --device=bluez_output.17:1A:35:8D:A2:A4 -v
Opening a playback stream with sample specification 's16le 2ch 44100Hz' and channel map 'front-left,front-right'.
Connection established.
Stream successfully created.
Buffer metrics: maxlength=4194304, tlength=352800, prebuf=349276, minreq=3528
Using sample spec 's16le 2ch 44100Hz', channel map 'front-left,front-right'.
Connected to device bluez_output.17:1A:35:8D:A2:A4 (index: 68, suspended: no).
Stream started.
Time: 2.925 sec; Latency: 2062081 usec.

Disconnect a remote device

To disconnect a remote device, run the following command from the bluetoothctl menu:

disconnect <bt_address>

Parameters <bt_address> is the Bluetooth address of the remote device. Example To disconnect a paired remote device with <bt_address> 17:1A:35:8D:A2:A4, run the following command:

disconnect 17:1A:35:8D:A2:A4

Sample output

[MySoundbar]# disconnect 17:1A:35:8D:A2:A4
Attempting to disconnect from 17:1A:35:8D:A2:A4
[DEL] Transport /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1/fd2
[DEL] Endpoint /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep1
[DEL] Endpoint /org/bluez/hci0/dev_17_1A_35_8D_A2_A4/sep2
[CHG] Device 17:1A:35:8D:A2:A4 ServicesResolved: no
Successful disconnected
[CHG] Device 17:1A:35:8D:A2:A4 Connected: no

​Prerequisites

​Connect a remote device

​List available transport

​Get information about codec capabilities

​Set absolute volume

​Play an audio file

​Get a list of sinks

​Play audio on a specific sink

​Disconnect a remote device

Prerequisites

Connect a remote device

List available transport

Get information about codec capabilities

Set absolute volume

Play an audio file

Get a list of sinks

Play audio on a specific sink

Disconnect a remote device