I’m trying to setup a simple audio player within my application.
I’ve heard about balena-sound, but I want to integrate some audio into my application, so balena-sound will not help me with this. I’ve used it as an example though!
Starting at the beginning, I’m stuck already. I have an Alpine container (
balenalib/raspberrypi4-64-alpine-node:12), where my application is running. I’ve added the
alsa-utils package and tried to do the speaker-test via the 3.5mm jack. But not a sound is coming out of my speakers.
aplay, I’m getting the following output:
$ aplay -L null Discard all samples (playback) or generate zero samples (capture) default:CARD=Headphones bcm2835 Headphones, bcm2835 Headphones Default Audio Device sysdefault:CARD=Headphones bcm2835 Headphones, bcm2835 Headphones Default Audio Device $ aplay -l **** List of PLAYBACK Hardware Devices **** card 0: Headphones [bcm2835 Headphones], device 0: bcm2835 Headphones [bcm2835 Headphones] Subdevices: 8/8 Subdevice #0: subdevice #0 Subdevice #1: subdevice #1 Subdevice #2: subdevice #2 Subdevice #3: subdevice #3 Subdevice #4: subdevice #4 Subdevice #5: subdevice #5 Subdevice #6: subdevice #6 Subdevice #7: subdevice #7
So there is a bcm2835 Headphones card found.
I’ve seen people getting success with using
amixer cset numid=3 1, but that command doesn’t succeed. Here’s the output of some
$ amixer cset numid=3 1 amixer: Cannot find the given element from control default $ amixer contents numid=2,iface=MIXER,name='Headphone Playback Switch' ; type=BOOLEAN,access=rw------,values=1 : values=on numid=1,iface=MIXER,name='Headphone Playback Volume' ; type=INTEGER,access=rw---R--,values=1,min=-10239,max=400,step=0 : values=400 | dBscale-min=-102.39dB,step=0.01dB,mute=1
On other forums, I saw that there should be another card, the HDMI card. But it just shows the headphones.
Some details about the Pi itself:
Raspberry Pi 4 (64-bit image)
BalenaOS 2.73.1+rev1 (development image)
dtoverlay=miniuart-bt dtoverlay=pi3-miniuart-bt enable_uart=1 arm_64bit=1 avoid_warnings=1 disable_splash=1 dtparam=i2c_arm=on dtparam=spi=on dtparam=audio=on gpu_mem=16
Container is running privileged, UDEV and dbus are both enabled.
Any help would be welcome!