Can MMM-GoogleAssistant and MMM-awesome-alexa run together?

[sdetweil]

@martinhood have to pick 1. there is no microphone sharing. whoever gets the mic 1st wins

[martinhood]

Thanks for your feedback.
That actually does make sense.
What about “virtualizing” mic layer with ALSA? (I read something about “aliasing” hd devices, if I’m not wrong).
Otherwise, could adding a second hw mic solve the problem in your opinion?

Thank you,
Daniele

[sdetweil]

@martinhood no idea on virtualizing

second mic… maybe. haven’t tried that myself

[martinhood]

I’ll try and let you know. Thank you!

[martinhood]

I finally managed to make it work. Actually it was easier than I thought.
The problem was in my initial MMM-GoogleAssistant configuration.
I try to give some details.

Background: As far as I understood there are multiple layers in Linux audio. Put very raw: PulseAudio is frontend, sitting on ALSA that controls underlying hardware (so PA -> ALSA -> OS -> HW).
PulseAudio’s job is exactly to take care and manage multpiple audio flows at a higher locigal level, so it IS capable of managing multiple applications accessing same in/out channels

MMM-awesome-alexa uses SOX by default, and there is no (easy) way to configure it. SOX uses PulseAudio by default (which is OK)

MMM-Google Assistant can be configured to use SOX (so PulseAudio) OR ALSA directly.

I initially had my GA configured to use ALSA, like that:
micConfig: { // put there configuration generated by auto-installer
recorder: “arecord”,
device: “plughw:0”,
},

This is OK for standalone, but binding directly to ALSA makes PulseAudio unable to manage multiple access to the mic (by Alexa, for example)

It was enough to configure GA to use SOX (which is actually the default, for a reason):
micConfig: { // put there configuration generated by auto-installer
},
This way both GA and Alexa go through PulseAudio, which is capable to make them work together.

I hope my poor English was enough to make it clear.

PS: I am unaware if PulseAudio layer is available on Raspberry OS, I am using Debian Buster on x86 VM where it is installed and available by default

[sdetweil]

@martinhood I have no idea how u got both wave recorders running at the same time

[martinhood]

I did literally nothing but remove any value from “micConfig:” section in MMM-GoogleAssistant.

But now that you make me double check, I saw that this does not defaults the recorder to “sox”. It actually defaults to “arecord” again.

Then actually, the working step is removing directive
device: “plughw:0”

It somehow prevents GA to try going directly “under” PulseAudio, and makes it use the PulseAusio ALSA plugin instead.
Once both goes through PulseAudio, they can work together, as PulseAudio cam make multiple wave recorders work by default