Datasheet

Now before you can change the volume you need to use the device once (this is an alsa thing)

Run

#This section makes a reference to your I2S hardware, adjust the card name

# to what is shown in arecord -l after card x: before the name in []

#You may have to adjust channel count also but stick with default first

pcm.dmic_hw {

type hw

card sndrpisimplecar

channels 2

format S32_LE

}

#This is the software volume control, it links to the hardware above and after

# saving the .asoundrc file you can type alsamixer, press F6 to select

# your I2S mic then F4 to set the recording volume and arrow up and down

# to adjust the volume

# After adjusting the volume - go for 50 percent at first, you can do

# something like

# arecord -D dmic_sv -c2 -r 48000 -f S32_LE -t wav -V mono -v myfile.wav

pcm.dmic_sv {

type softvol

slave.pcm dmic_hw

control {

name "Boost Capture Volume"

card sndrpisimplecar

}

min_dB -3.0

max_dB 30.0

}