New audio mode config for FCDEV3B

Mychaela Falconia mychaela.falconia at gmail.com
Sat Oct 9 07:30:43 UTC 2021


Hello FreeCalypso community,

I got a new set of audio mode config files for FCDEV3B, for those
FCDEV3B users who got the loudspeaker+microphone voice call kit.  The
new spkr0 audio mode config has AEC enabled (needed so that the party
on the other end of the call won't hear a delayed echo of their own
voice), has the microphone gain tuned so that your speech will be
transmitted at the expected level (same as standard phones), and has
the sidetone level turned down appropriately.  Audio mode configs are
separate from the firmware code image (they reside in FFS), thus if
you have an FCDEV3B and you would like to install this audio mode
update, you will need to follow this special procedure:

1) Update your FC host tools to the latest fc-host-tools-r16 release -
earlier versions won't work.

2) Flash your FCDEV3B with recent Tourmaline-based firmware, either
the latest 20210811 official binary release I recently put out, or
your own build from source - but it must be Tourmaline, not any of the
older source trees.

3) Get the latest fc-audio-config from Mercurial:

https://www.freecalypso.org/hg/fc-audio-config/

Run 'make', then 'make install' in fc-audio-config - the new files
will be added to your /opt/freecalypso installation.

4) Upload the new audio mode config files (compiled and installed on
your host system in the previous step) to your FCDEV3B:

fc-fsio upload-subtree /opt/freecalypso/aud-fcdev3b /aud

Once you have done all of the above steps, your FCDEV3B update is
complete.  However, for the new audio mode to take effect, you will
need to issue the following command in every boot session, before the
first voice call or other audio activities:

AT at AUL="spkr0"

This command should be issued at same point in the bring-up sequence
when you enable the loudspeaker with AT at SPKR=1.  Both commands are
necessary, and can be given in either order.  AT at AUL loads the audio
mode config file and sets various audio-related knobs in the
Calypso+Iota chipset, whereas AT at SPKR controls the FCDEV3B-specific
loudspeaker amplifier which is external to the core chipset.

Happy hacking,
Mychaela aka The Mother


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