yeah. I looked at that commercial site.
The smart phone has power to the 3.5mm port. Not sure if his PC does.
If it does not....he needs to buy the battery and slide the switch to ON.
https://imgur.com/NDt2obI
since it needs power.....it will have its own mixer so you should be able to see its levels by
copying and pasting command into a terminal.
Code:
alsamixer -c1 -Vall
If you can't see it...press F6 to see if you can see it.
I don't have a powered mic....but can cheat by showing a standard mic thru an usb sound mixer
https://imgur.com/hz4CD0F
use the arrow keys to get to mic....press either m key to unmute....or (space bar) to activate
raise volumes and test with arecord command for fair sound quality as follows
Code:
arecord -d 5 -f cd test.wav
5 seconds with a filename=test.wav cd quality=44100 Hz, Stereo
man arecord has more options and once you know what your device can deliver you can up the quality.