Merge pull request 'mavwaked has no wake word, only an energy VAD — add silero-vad and a keyword gate' (#223) from task/487-capture-device-doc into master

docs/deployment.md

@@ -166,9 +166,21 @@ the GPU. A model that will not load is logged and not fatal.
 `-barge-in` is not passed. The threshold is room-specific and this room has no
 number yet. Read the "suppressed while speaking" means out of the journal first.
 
-The device is `plughw:0,0` and not `hw:0,0`. The fifine offers 2 channels at
-44100 or 48000 and nothing else, and mavwaked asks arecord for 16kHz mono. Bare
-`hw` dies on "Channels count non available" before a frame is read.
+The device is `plughw:CARD=Gen,DEV=0`, the Scarlett Solo. It is `plughw` and
+not `hw` because mavwaked asks arecord for 16kHz mono. No microphone here
+offers that, so bare `hw` dies on "Channels count non available" before a
+frame is read. It is named `CARD=Gen` and not card 4 because a USB card number
+moves when something else is replugged.
+
+It used to be the fifine on card 0, and that cost three days. mavwaked logged
+zero completed utterances across them, before the wake word existed and after.
+The fifine returns RMS 0.00004 with its capture switch on and its ALSA volume
+at the full 496 of 496. That silence is in the hardware and no flag reaches
+it. Over the same eight seconds of speech the onboard ALC897 read 0.142 and
+the camera 0.289, both clipping at peak 1.0. The Scarlett read 0.003 clean.
+
+Check the level before blaming the gate. Stop the unit, run `arecord` against
+the device for five seconds, and measure. A live room floor reads near 0.001.
 
 The three `-wake-` flags require the keyword "Мэйвен" (V-487 stage two). Drop
 them and the loop runs open, which is what it did before. The threshold is the