[SOLVED] Issues with Mics on Matrix Creator

Hi there!

I was attempting to take on the Matrix Google Assistant project, and got some errors. In the video tutorial, it said you could run arecord recording.wav -f S16_LE -r 16000 -d 5 to test the mics. However, when I ran the command, I got this error:

pi@raspberrypi:~ $ arecord recording.wav -f S16_LE -r 16000 -d 5
ALSA lib pcm_hw.c:1713:(_snd_pcm_hw_open) Invalid value for card
arecord: main:788: audio open error: No such file or directory

I have researched solutions, but found nothing. I’m stuck. :tired_face:

Welcome to the community @coolmandude545!

It sounds like you’re on the newest kernel version.
If you type uname -a | grep 4.19 in terminal and see something show up, then you will need to downgrade the kernel, as our kernel modules are currently incompatible with kernel version 4.19.

Please follow this thread for instructions on downgrading the kernel. Kernel Modules 4.19 Workaround.

After the kernel is downgraded arecord should work again.

Feel free to ask if you need more help. :slight_smile:


Thanks for the reply! :grinning: Prior to my post, I followed that thread, and it said that that the modules were successfully installed. I then tried arecord and it gave the same error. I will try arecord again just to be sure and will post the results.


Please try the following (after doing the steps in the thread linked above).

sudo apt purge matrixio-kernel-modules
sudo reboot

curl https://apt.matrix.one/doc/apt-key.gpg | sudo apt-key add -
echo "deb https://apt.matrix.one/raspbian $(lsb_release -sc) main" | sudo tee /etc/apt/sources.list.d/matrixlabs.list

sudo apt-get update
sudo apt-get upgrade

sudo reboot

sudo apt install matrixio-kernel-modules

sudo reboot

Also, please provide the output of
cat /etc/asound.conf

I tried arecord one more time before following in the instructions you gave me and it worked! I believe the pi just needed a reboot when I downgraded the kernel. Thanks for helping me, @Boris!