No audio through BT-connected car stereo

I can’t remember if it ever worked, but it definitely does not now. I have my music library loaded on the uSD card in my Librem5 phone, and have played it using both supersonic and vlc through my BT-connected Denon home amplifier. However, when connected to my Corolla’s stereo, I get no sound through the phone or the car.

In general, I have become extremely disappointed in the overall usefulness of the device. Many common tasks are either difficult or impossible, usually do to problematic software. Many of the issues have been discussed here, but don’t seem to ever really improve with updates.</soapbox mode>

Could someone please suggest how to track down the issue here?

EDIT: I should add, that the car system reports it understands OPP,PBAP,A2DP,AVRCP,MAP (whatever those mean)

Thanks and kind regards,

Dave

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I do not think the Librem 5 is for typical Linux users, who expect to be able to do everything on it that they can do on a Android/Linux device.
Due to the complexity and security features of the L5, many things simply wont work the same way as on a standard Android/Linux device running…

So to me Crimson still for Brave User, Crimson still hurt the L5, Dawn will much much better overall which many things will work like a butter…

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I am a seasoned Unix and Linux user, very comfortable with the command line.

What I expect is that if BT audio works for a headset and an amplifier, it should work with the car audio as well.

Constructive suggestions as opposed to editorial remarks will be greatly appreciated.

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Redpine do not HFP, so when start pairing the connection, reject PBAP if so to direct enable A2DP.

For starters, tell us whether you have a Redpine or SparkLAN card, and which PureOS release are you using.

I have whatever the stock Librem5 is, as updated to current software updates. os-release says “PureOS 10 (Byzantium)”

dmesg does not show a device when I grep Bluetooth. btmgmt info says hci0 is mfr 15 class 0x30110.

hciconfig -a reports it as a Broadcomm device. But from this guide: Check Bluetooth Adapter Version and Status on Linux - Power Sysadmin Blog it seems that Librem5 has the oldest possible BT hardware? Yuck.

What I’ve been able to find online suggests that neither bluetooth nor pulseaudio are very stable, so I’m not very hopeful at the moment.

dmesg shows some messages that may or may not coincide with the connection and audio play attempts:
Bluetooth: hci0: sending frame failed (-49)
Bluetooth: hci0: Opcode 0x0c03 failed: -49

Messages (lots of them) on the console that ran vlcplayer:
vlspulse audio output error: cannot write: Bad state

I have similar issues with my Librem11 tablet. I got some audio momentarily but then it dropped out again. Haven’t dug through logs there. The L11 has the Crimson version of PureOS.

With WiFi on, nmcli -f GENERAL.DRIVER d show wlan0 will tell you which driver is being used.

brcmfmac means SparkLAN card; RSI-SDIO WLAN means Redpine.

See New Post: Shipping new SparkLAN Wifi cards with Librem 5 - #25 by dos

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I’m not understanding why you’re asking about wifi, I’m talking about Bluetooth. Is it the same hardware for both?

command says: “brcmfmac”

Yes. The card - either the old one or the new one - does both WiFi and Bluetooth.

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What security features impact Bluetooth audio?

That’s why 1 kill switch turn off/on both WiFi and bluetooth instead of to have 2 separated kill switches one for each single function. It’s because kill switch literally stop electricity to that single hardware component (WIFI+BT), right?

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I cannot help much with your issue, but two things I have observed:

  1. What works and what doesn’t varies a bit from device to device, in regards to the L5 and Bluetooth. You might find it works in another car just fine (not that it helps you in your car).
  2. I’ve had a lot more successes and stability with Bluetooth since upgrading from Byzantium to Crimson.
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That’s correct. If you are going to cut power to the module - which is the most definitive way of silencing the radio - there simply is no way to switch WiFi and Bluetooth independently of each other. They are either both powered on or both powered off.

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8 responses so far and no closer to any indication of whether this behavior can be corrected, or even where to start looking. At this point my L5 is not quite useless but close. So much of the software simply does not function reliably, or at all.

I have experience with Mobian and postmarketOS with bt-connected car stereo. The car stereo can work as “headphone” and play back sound from the device, but making phone calls won’t work there due to extensive echo and not being able to use the car’s microphone as input. This is supposed to improve in the future when pipewire and audio roles become stable.

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I just connected to the RetroSound 4HD aftermarket radio in my classic truck. Works pretty well (occasional dropout) for playing audio from the phone – even shows artist/track or stream on the scrolling LED display and correctly uses the forward/backward buttons. Where it falls flat for me is when the phone rings for an incoming call. When I answer, no one can hear me. Probably has something to do with which source and sink are selected (I’m too task saturated to investigate whist driving). Since people insist on calling during my podcasts, I either disable the cell
modem or simply use a cable to the aux port on the radio, which works perfectly except for having to manually pause the program before answering the call. Ironically, when the call disconnects the program resumes automatically.

Edit: L5 Evergreen, Crimson.

That’s because it generally works. I can connect my Librem 5 to several Bluetooth devices I have around in here and it works flawlessly. Some people complained about audio stuttering with some devices, but not being able to connect at all is uncommon, so you’ll have to investigate what’s different in your particular setup.

Does your car’s audio work with GNU/Linux laptops? Perhaps there’s a difference in compatibility between PulseAudio and PipeWire? Check it out.