[MinnowBoard] Audio playback through jack line output

[Darren Hart]

From:  Robert <robertdegruijl at hotmail.com>
Reply-To:  MinnowBoard Development and Community Discussion
<elinux-minnowboard at lists.elinux.org>
Date:  Monday, May 12, 2014 at 10:08
To:  "." <elinux-minnowboard at lists.elinux.org>
Subject:  [MinnowBoard] Audio playback through jack line output


>Hi
>I'm trying to do basic audio playback through the Minnowboard jack line
>output, using a c-program sending a PCM data to an audio device. Does
>anyone have documentation or tips on how to do this using the standard
>Linux Angstrom image from minnowboard.org?
>
>The only playback device I see is /dev/snd/pcmC0D0p, but opening and
>sending PCM data to this fails (write returns -1).
>
>I cannot find any linux OSS modules (modprobe snd-pcm-oss) in the
>Angstrom distribution to create a /dev/dsp or /dev/audio device
>
>I don't seem to have a full ALSA support either, I don't have
>/usr/include/alsa/asoundlib.h. I only have  /usr/include/sound/asound.h
>which does not have the basic function calls such as snd_pcm_open().
>
>Is there a standard way of PCM audio playback on the Angstrom OS image
>for Minnowboard, or do I need to install additional audio drivers and/or
>ALSA modules?
>
>Thanks!
> 		 	   		  

Hi Robert,

I believe your question is fundamentally an Alsa programming / Angstrom
question - more than a minnow question (which is fine), but I did want to
confirm that your device is working physically. Do the speakertest and/or
aplay programs successfully send output to the device?

Koen could say for sure, but typically the headers for packages in
Angstrom or in -dev named versions of the base packages.

For example, you can use opkg to list the available packages, are there
some alsa -dev package available to install?


--
Darren Hart			Open Source Technology Center
darren.hart at intel.com		Intel Corporation