Differences

This shows you the differences between two versions of the page.

--- mixer_settings [2012/01/22 07:50] – created paulf
+++ mixer_settings [2012/04/05 10:58] (current) – torwag
@@ Line 8: / Line 8: @@
 Understanding it doesn't require any special knowledge, here's a short legend:
-  * ''DAC'' is [[http://en.wikipedia.org/wiki/Digital-to-analog_converter|Digital to Analog Converter]], ''DACs'' module gets digital stereo signal via ''I2S'' bus from the CPU and the ''VoiceDAC'' module gets mono signal from a digital microphone (placed somewhere inside near the webcam)
+  * ''DAC'' is [[http://en.wikipedia.org/wiki/Digital-to-analog_converter|Digital to Analog Converter]], ''DACs'' module gets digital stereo signal via ''I2S'' bus from the CPU (''VoiceDAC'' module is left unconnected an ac100)
   * ''ADC'' does the reverse and can be used to convert sound from inputs to digital form which is then sent over ''I2S'' to the CPU
+  * DMIC is a digital microphone, connected to special pins of the integrated webcam
   * A triangle on the diagram means a sound amplifier
   * A square marked ''Vol'' is an [[http://en.wikipedia.org/wiki/Attenuator_(electronics)|attenuator]] that a user can tweak to reduce the volume of the signal
@@ Line 23: / Line 24: @@
   * ''DACR2HP Playback Switch''
   * ''Int Spk''
+  * ''Speaker Playback Switch'' (i.e. unmute ''Speaker'')
 Should be set:
   * ''SpeakerOut Mux'' to ''HPOut Mix''
@@ Line 29: / Line 31: @@
 Proper mono sound via MONO mixer or Speaker mixer is impossible to produce on unmodified hardware, see [[hw_problems#reversed_polarity_of_one_of_the_integrated_speakers]] for details. Luckily most usage scenarios do not require that anyway. You can swap polarity of connection of one of the speakers but then ''RN/-R'' would need to be used for the stereo output.
+==== Stereo playback on headphones ====
+Same as stereo playback on integrated speakers but with
+Enabled:
+  * ''Headphone Playback Switch'' (i.e. unmute ''Headphone'')
+Set:
+  * ''Left Headphone Mux'' to ''HP Left Mix''
+  * ''Right Headphone Mux'' to ''HP Right Mix''
+To mute the internal speakers you can disable ''Int Spk'' or mute ''Speaker''.
+==== Recording sound from integrated DMIC ====
+This can be used to record sound from the digital microphone integrated in the webcam module, useful for e.g. VoIP
+Selected for capture:
+  * ''DMIC En Capture Switch''
+  * ''DMIC PreFilter Capture Switch''
+  * ''DMICL Mix DMICL2ADC Capture Switch''
+Set:
+  * ''I2SOut Mux'' to ''ADC LR''
+Tweak ''DMIC Boost Volume'' and ''Rec Capture Volume'' to your needs.
+==== Recording from external microphone ====
+Selected for capture:
+  * ''Left Capture Mix MIC12REC_L Capture Switch''
+Tweak ''Mic 1 Boost Volume'', ''Mic1 Capture Volume'' and ''Rec Capture Volume'' to your needs.
+==== Save and Restore different sound settings  ====
+Don't frighten you do not need to memorize all the above settings.
+If you select the settings in alsamixer according to your needs type on the command line:
+<code>
+# alsactl store -f <name>
+</code
+e.g.
+<code>
+# alsactl store -f headphones.state
+</code>
+Now, if you want to switch over to your headphone settings next time simply type
+<code>
+alsactl restore -f headphones.state
+</code>
+Hence, you can save settings for internal speakers, headphones, mute all, etc.
+If you do not want to type all the above to restore just create a little shell script (name it e.g. setsound.sh) to do that for you.
+<code>
+#!/bin/sh
+# Set alsa sound to a predefined state
+# save state via
+# alsactl store -f <name>.state
+# call this this by
+# ./setsound headphones
+alsactl restore -f {$1}.state
+</code>
+make the file executable
+<code>
+# chmod +x ./setsound.sh
+</code>
+now you can set sound settings by simply typing
+<code>
+# ./setsound.sh headphone
+</code>