Hi!. This is my first post here in Olimex.
I'm using a A13-SOM module on a custom hardware. I can't use the microphone input. In order to test I'm using this command:
arecord -d 10 /tmp/test-mic.wav
But a get the following error:
ALSA lib pcm_direct.c:1505:(_snd_pcm_direct_get_slave_ipc_offset) Invalid value for card
arecord: main:682: audio open error: No such file or directory
What I need to do??
Did you google / search for each of the main terms / messages you posted? And then what happened?
E.g. I found https://www.olimex.com/forum/index.php?topic=2856.0
John
/etc/asound.conf is maybe configured for a A10 or A20 had that problem here, removing or renaming this file could be the solution, have to restart ALSA or the board to see the effect
JohnS, I did a google search but I can't find anything that help me.
Gerrit, I deleted the /etc/asound.conf file and the error dissapear BUT I can't still make any mic capture.
To test I'm using these commands:
arecord -d 10 /tmp/test-mic.wav
and
aplay /tmp/test-mic.wav
Also I changed a lot of things using the http://linux-sunxi.org/Audio_Codec guide but any success yet.
To clarify I'm using an electret microphone that work great when use Android instead Linux.
Most likely just a matter of getting the mixer settings right.
with arecord - |aplay - you can hear what you do with a second delay or something.
on a A13-OLinuXino-WIFI i have these settings with alsamixer
F3: [PLAYBACK]
Master 83
Master C 00
Mic Power 00
Mic2 Boost 00
MicL 67
Playback 00
ADC Input Mux 29
Left Capture Mute 00
F4: [CAPTURE]
MicL 33
Capture 71
ADC Input Mux 29
the levers that are not mentioned don't have any effect for recording from mic in
Adjust Master / MicL and Capture levels to get the right volume for your set up.
Gerrit, THANK YOU VERY MUCH.
I set the alsamixer controls as you showed me and it works great.
Once again, thank you for your time.