seeed-voicecard

While the upstream wm8960 codec is not currently supported by current Pi kernel builds, upstream wm8960 has some bugs, we had fixed it. we must it build manually.

We also write ac108 rapberry pi linux kernel driver.

Get the seeed voice card source code.

git clone https://github.com/respeaker/seeed-voicecard
cd seeed-voicecard
#2mic
sudo ./install.sh 2mic
#4mic
sudo ./install.sh 4mic
reboot

Check that the sound card name matches the source code seeed-voicecard.

#2mic
pi@raspberrypi:~/seeed-voicecard $ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: ALSA [bcm2835 ALSA], device 0: bcm2835 ALSA [bcm2835 ALSA]
  Subdevices: 8/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
card 0: ALSA [bcm2835 ALSA], device 1: bcm2835 ALSA [bcm2835 IEC958/HDMI]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 1: seeed2micvoicec [seeed-2mic-voicecard], device 0: bcm2835-i2s-wm8960-hifi wm8960-hifi-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
pi@raspberrypi:~/seeed-voicecard $ arecord -l
**** List of CAPTURE Hardware Devices ****
card 1: seeed2micvoicec [seeed-2mic-voicecard], device 0: bcm2835-i2s-wm8960-hifi wm8960-hifi-0 []
  Subdevices: 1/1
  Subdevice #0: subdevice #0
pi@raspberrypi:~/seeed-voicecard $ 

#4mic
pi@raspberrypi:~ $ arecord -L
null
    Discard all samples (playback) or generate zero samples (capture)
playback
capture
dmixed
array
ac108
default:CARD=seeed4micvoicec
    seeed-4mic-voicecard, 
    Default Audio Device
sysdefault:CARD=seeed4micvoicec
    seeed-4mic-voicecard, 
    Default Audio Device
dmix:CARD=seeed4micvoicec,DEV=0
    seeed-4mic-voicecard, 
    Direct sample mixing device
dsnoop:CARD=seeed4micvoicec,DEV=0
    seeed-4mic-voicecard, 
    Direct sample snooping device
hw:CARD=seeed4micvoicec,DEV=0
    seeed-4mic-voicecard, 
    Direct hardware device without any conversions
plughw:CARD=seeed4micvoicec,DEV=0
    seeed-4mic-voicecard, 
    Hardware device with all software conversions
pi@raspberrypi:~ $ 

If you want to change the alsa settings, You can use sudo alsactl --file=asound.state store to save it.

Test:

#2mic 
arecord -f cd -Dhw:1 | aplay -Dhw:1

#4mic
arecord -Dac108 -f S32_LE -r 16000 -c 4 a.wav

with Google Assistant

if you run the assistant but the playback is speed up considerably, try to configure alsa:

sudo cp asound.conf /etc/asound.conf

If the alsa configuration doesn't solve the issue, try to use pulseaudio. See #4

Enjoy !