Rock 3C Audio (Debian Bullseye)

#1

Hello,

Running https://github.com/radxa-build/rock-3c/releases/download/b43/rock-3c_debian_bullseye_cli_b43.img.xz in headless Radxa Rock 3C, what needs to be done for Alsamixer to show the audio level controls ?

cat /proc/asound/cards
0 [rockchiprk809 ]: rockchip-rk809 - rockchip-rk809
rockchip-rk809
1 [rockchiphdmi0 ]: rockchip-hdmi0 - rockchip-hdmi0
rockchip-hdmi0

Thanks !

#2

You can use the aplay -l command to see what sound cards are registered on your system.

You can specify which sound card you want to use to play the sound with the following command
(According to the information you provided above, the serial number of rk809 is 0.)

aplay -D hw:0,0 ./sound.wav

Of course, you can also specify the sound card for recording with the following command

arecord -D hw:0,0 -d 4 -f cd -r 44100 -c 2 -t wav ./mic_test.wav
#3

Thanks Mitchell !

The problem occurs as user “root”.

AlsaMixer v1.2.4

Alsamixer as user “radxa” or as user “rock” shows audio level controls, both input and output.
Alsamixer info:
Card: PulseAudio
Chip: PulseAudio

Alsamixer as user “root” does not show such audio controls.
Alsamixer info:
Card: rockchip-rk809
Chip:

Alsamixer behavior differs between user and superuser. How can this be resolved ?

#4

This issue is probably related to PulseAudio.
To make things simpler, cleaner, it is convenient to work without PulseAudio, especially on headless computers.

amixer scontrols
Simple mixer control ‘I2STDM Digital Loopback Mode’,0
Simple mixer control ‘Playback Path’,0
Simple mixer control ‘Capture MIC Path’,0

#5

I removed PulseAudio:
apt-get remove --purge pulseaudio

By connecting an external audio card to the central USB connectors, the audio works correctly:
cat /proc/asound/cards
0 [rockchiprk809 ]: rockchip-rk809 - rockchip-rk809
rockchip-rk809
1 [Device ]: USB-Audio - USB PnP Sound Device
C-Media Electronics Inc. USB PnP Sound Device at usb-xhci-hcd.3.auto-1, full sp
2 [rockchiphdmi0 ]: rockchip-hdmi0 - rockchip-hdmi0
rockchip-hdmi0

Alsamixer shows 4 audio level controls:
Playback

  • Speaker
  • Mic
  • Auto Gain Control

Capture

  • Mic

Unfortunately this does not happen with the “rockchiprk809” and “rockchiphdmi0” boards that are on the motherboard.
Are there drivers missing for the “rockchiprk809” and “rockchiphdmi0” boards ?

Thanks !

#6

I reproduced to the problem you described. Are you going to use the cli version of the image to resize the sound via alsamixer?

When I use the b43 cli version, it seems that under the radxa/rock user, I can’t use alsamixer to resize the rk809 and the hdmi when it’s playing the sound.

But when I use b43 xfce version, I can use alsamixer to resize rk809 and hdmi under radxa/rock user, but the situation is the same as cli under root.

#7

Thank you very much Mitchell.
Yes, I use only the CLI version. This is my first time installing a Debian CLI version that already includes PulseAudio and I don’t know how to get ALSA to have full control of the audio.