Balena Sound Bluetooth Volume Synchronisation

Project help balenaSound
1

Hi there i want to know if i could enable media volume sync with my mobile phone and the pi when i’m using spotify connect i can control the volume from my phone but when i’m using bluetooth i can’t. can i change that?

3

Hi

What mobile device are you using? You should be theoretically able to control the volume from your device. It’s how it works with my Google Pixel, for example.
You can find more explanations on how the RPi is set up in balenaSound readme:

5

I am using samsung galaxy s8 and when i try to turn the volume down its doing nothing

17

Hi, does it mute when you reach the very bottom of the volume indicator? Asking as in our testing with a Nokia android one phone, the volume curve was not linear, but exponential, and volume changes could be heard only when reaching the bottom of the indicator.
Thanks,
Zahari

19

i came across this post with the same issue myself this time a Galaxy s20Ultra. i know the post is pretty old but the volume does not control when connected to bluetooth. but indeed does mute when at the lowest point of the volume indicator.

23

Hi there, there is a bug with balenaSound version 3.0+ that’s causing this issue. Here is the bug report: https://github.com/balenalabs/balena-sound/issues/300

A fix for this should be coming soon (next week hopefully). You can track progress via GitHub and I’ve also linked the issue to this forums thread so you’ll get notified when it gets resolved.

25

Hi, I’m using a Samsung Galaxy S21+ and I’m unable to control bluetooth volume except when it mutes at 0. I tried the suggested fix in the github link but no luck. Any update on this?

28

Hey, we haven’t had the chance to look into it just yet. I’ll try to make some time in the next week or so and see if I can tackle this.

30

Hi, I’m also having this issue. (Galax S21, RPi 4). I implemented the fixes from the GitHub info but it still doesn’t work. Below is the result from a “systemctl status bluetooth” command. I’m a total Linux/Bluez rookie and the error messages at the end don’t mean anything to me. Any and all help is greatly appreciated.

● bluetooth.service - Bluetooth service
Loaded: loaded (/etc/systemd/system/bluetooth.service; enabled; vendor preset: enabled)
Drop-In: /etc/systemd/system/bluetooth.service.d
└─bluetooth.conf
Active: active (running) since Mon 2021-08-30 19:57:51 UTC; 14min ago
Docs: man:bluetoothd(8)
Main PID: 1798 (bluetoothd)
Status: “Running”
Tasks: 1 (limit: 4524)
Memory: 2.5M
CGroup: /system.slice/bluetooth.service
└─1798 /usr/libexec/bluetooth/bluetoothd --plugin=a2dp

Aug 30 19:57:51 balena bluetoothd[1798]: …/bluez-5.58/src/adapter.c:reset_adv_monitors_complete() Failed to reset Adv Monitors: Unknown Command (0x01)
Aug 30 19:57:52 balena bluetoothd[1798]: Failed to set privacy: Rejected (0x0b)
Aug 30 19:57:58 balena bluetoothd[1798]: …/bluez-5.58/src/service.c:btd_service_connect() a2dp-source profile connect failed for 8C:DE:E6:5B:86:42: Protocol not available
Aug 30 19:58:03 balena bluetoothd[1798]: …/bluez-5.58/src/service.c:btd_service_connect() a2dp-source profile connect failed for 8C:DE:E6:5B:86:42: Protocol not available
Aug 30 19:58:31 balena bluetoothd[1798]: …/bluez-5.58/src/service.c:btd_service_connect() a2dp-source profile connect failed for 8C:DE:E6:5B:86:42: Protocol not available
Aug 30 19:58:36 balena bluetoothd[1798]: …/bluez-5.58/src/service.c:btd_service_connect() a2dp-source profile connect failed for 8C:DE:E6:5B:86:42: Protocol not available
Aug 30 19:58:41 balena bluetoothd[1798]: …/bluez-5.58/src/service.c:btd_service_connect() a2dp-source profile connect failed for 8C:DE:E6:5B:86:42: Protocol not available
Aug 30 19:58:46 balena bluetoothd[1798]: Endpoint registered: sender=:1.217 path=/MediaEndpoint/A2DPSink/sbc
Aug 30 19:58:46 balena bluetoothd[1798]: Endpoint registered: sender=:1.217 path=/MediaEndpoint/A2DPSource/sbc
Aug 30 20:02:14 balena bluetoothd[1798]: /org/bluez/hci0/dev_8C_DE_E6_5B_86_42/fd0: fd(23) ready

31

Hey @bmumm,

Sorry for the late response here. Have you tried any of the suggestions and troubleshooting tips from the conversation here? Any additional feedback or logs would be helpful as the community and team working on the issue can get closer to a fix.

33

Hi Andrew,

I got it working using the published fixes….my issue was that after I applied the fixes, I needed to delete balena from my existing Bluetooth connections on my phone, then reboot the phone and re-add connection. Then it worked…and it’s been stable since.

While I have you, tho, I do have one remaining issue. There is about a 20 second delay between adjusting volume or changing music on my phone before it happens on the balena device. Any suggestions on how I could reduce this lag time?

Thanks,

Barry

34

Hi Barry,

I have the same. When I reboot my pi the delay is back to about 2-3 seconds

Cheers,

Bjorn

35

@bmumm, @formatc, regarding the delay, that’s due to the audio service building up latency over time. This happens whenever the device CPU is heavily taxed and can’t process the audio samples in real time. This usually happens with low end devices such as the Raspberry Pi Zero, or if you are using a bad power supply. A reboot usually will fix it because the latency gets reset. There is an open issue in GitHub to track this however I haven’t had the bandwidth to look at this yet (Input latency slowly increases over days in multi-room mode · Issue #477 · balenalabs/balena-sound · GitHub).