asoundrc

#The below 2 sections are commented, they control the default sound card to use
#This set up is for a Pi with an I2S microphone attached using the guide
#from adafruit at
# https://learn.adafruit.com/adafruit-i2s-mems-microphone-breakout
#Uncomment and the I2S will be your default card (assuming same setup)
#but you won't get audio playback because both recording and playback will be
#defaulted
#TODO - Figure out how to set default for recording separately
#To adjust use aplay -l to work out the devices you have and their card number
#For recording devices use arecord -l

#pcm.!default {
#	type hw
#	card 1
#}

#ctl.!default {
#	type hw           
#	card 1
#}

#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
}