balenaSound project: No such device ERROR

I’m new to the forum, and to too. I got interested in this project while writing a SD card on Etcher.
A very interesting project, I’ve completed it without any problems. It shows up in the dashboard over the WiFi network I entered when downloading the OS, my RPI 3A+ also received the code it was pushed to. But when I connect my phone, iPhone 5s, to balenaSound 16a7, and try to play music over the “Music” app on my phone, my speakers (which I tested, they work), don’t make any noise. So I check the dashboard, and in the log I get this error: 30.08.19 08:59:26 (-0400) bluetooth-audio /usr/bin/bluealsa-aplay: Couldn’t open PCM: No such device. A picture:


How should I fix it?
Thanks in advance!

Hey @PolarBear123 welcome to the forum and thanks for trying the project. It sounds like you’ve done everything right, but could you give balenaOS 2.38 a try for me? When you go to add new device and download the OS you’ll see it as an option in the dropdown menu.

Thanks for the rapid response. I’ve tried the OS in 2.38. I had some problems erasing the SD card, but I managed to do it using diskutil eraseDisk FAT32 RPI disk2 with RPI being the new name of the SD card. I run that command in Terminal in Mac OS and I flashed it with Etcher. I then put it in the RPI, but, the green LED blinks three times, like bliiiiiiiiiiiiiiiink, bliiink, bliiink, and then it stays off, the red one still one, forever. It doesn’t show up in the Dashboard.

One thing I’ve changed: When I installed the newer OS before, I had production mode on. Now I have development mode on. But I don’t think that makes a difference.

Does anyone know what’s been happening now? Before, the OS worked, now this older one, it doesn’t work at all!


I’ve seen solid red LED on my own projects when i’m under-powering the device. Is this possibly affecting your setup?

If your device boots but is unable to connect to the balena VPN / API, you’ll see a repeating 4-blinks pattern on the green ACT LED [1]. Since this isn’t happening, and yet it’s not connecting to the dashboard either, this is an interesting state.

Since you’re using a development-mode image, you may be able to locate the device on your local network using sudo balena scan, at which point you could try to SSH into the device on port 22222 [2].

Then you could check systemctl list-units --state=failed, ping The first will show you whether any services have failed, and the second should be failing if your device is up but can’t reach the vpn (this is how a device indicates that it’s “online” in the dashboard).

You could also check journalctl -xa and try to find any errors there.


Thank you for your help. Before I got an answer to my question, I decided to re-flash the SD card with v2.3.8… and Development Mode on. It worked. Still, thank you for your answer.

But I got another question: Is it OK to keep the RPI running all the time? And if I’m away, or something, is it ok to just pull the plug of the Raspberry Pi with the bluetooth-audio running, or is it mandatory to shut it down over the web interface. And either way, does it boot up automatically with the bluetooth-audio up and running so I can put in the plug and directly connect my phone?

Thank you very much!

One thing to mention quickly: ping fails because we block ICMP for stability reasons. You’d be better to check the logs for the openvpn service, if your device is up, and you can SSH in, but it’s not connecting to the backend.

I know that the rpi 3B+ tends to have heat issues [1]. My 3B+ can get somewhat hot, but never have I had them go into a dangerous range even when leaving them on for days on end. If you don’t live in a very hot climate / have it in an enclosure with little air circulation / run it at CPU 100 all the time, and if you apply passive heatsinks (relatively cheap) applied to the CPU and wifi module, you should be just fine.

Generally, powering off the device off through the web interface, or through “poweroff” over ssh is safest, to ensure that any files being written don’t get corrupted (if your application writes files, that is). But the balena-sound app doesn’t write any files or rely on writing files, so in your case, if you aren’t in the midst of applying a host OS update, it’s totally safe to pull the plug.

If your application comes up and is available for bluetooth connection after boot one time, it’s highly likely everything is fine and yes, it’ll do that every time you boot, barring some strange non-deterministic issue.


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Ok, thank you!!