How do I get my I2S microphone on a Pi zero W working again after running rpi-update?

Question

I have an I2S breakout microphone from adafruit which I got working last week. However due to problems with my pi camera I ran rpi-update, and following this my microphone is not working.

I initially followed the walkthrough here. After the upgrade and initially finding the microphone didn't work, I cleaned out all the downloaded sources and the module and rebuilt.

Here is a console transcript:

pi@pizero:~ $ arecord -l
**** List of CAPTURE Hardware Devices ****
card 1: sndrpisimplecar [snd_rpi_simple_card], device 0: simple-card_codec_link snd-soc-dummy-dai-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
pi@pizero:~ $ arecord -t wav test.wav -d 10
arecord: main:788: audio open error: No such file or directory

I have discovered from searching that a device tree overlay might help (pages 30 and 31 in this thread for example) but I need a detailed walkthrough like the one I linked to in order to make use of that.

What do I need to do to get it working again?

Answer 1

"In normal circumstances there is NEVER a need to run rpi-update as it always gets you to the leading edge firmware and kernel and because that may be a testing version it could leave your RPi unbootable". https://www.raspberrypi.org/forums/viewtopic.php?p=916911#p916911 Even the rpi-update documentation now warns "Even on Raspbian you should only use this with a good reason. This gets you the latest bleeding edge kernel/firmware."

sudo apt-get update; sudo apt-get install --reinstall raspberrypi-bootloader raspberrypi-kernel will put it back to the latest supported kernel/bootcode.