demedeirosa
Posts: 17
Joined: Wed Jul 11, 2018 1:57 pm

WM8731 Output working, no input?

Thu Apr 18, 2019 8:04 pm

Hi all,

I've got a WM8731 on the MikroE board. Following this:
https://github.com/raspberrypi/linux/issues/1302

I was able to get the sound output working with no issues. However, I cannot seem to get the microphone input working. Using arecord, with the -V parameter set, I get no input on the VU meter. The file that is recorded is effectively blank.

I am running this on a Pi CM3L with Rasbian Stretch, kernel 4.14.50-v7+.

My /boot/config.txt is as follows:

Code: Select all


dtparam=spi=on
dtparam=i2c_arm=on
dtparam=i2s=on
dtoverlay=i2s-mmap
dtoverlay=rpi-proto
gpu_mem=512
lsmod reports the following:

Code: Select all

Module                  Size  Used by
can_raw                20480  0
can                    28672  1 can_raw
cfg80211              573440  0
rfkill                 28672  2 cfg80211
snd_soc_wm8731         20480  1
spidev                 16384  0
ax88179_178a           24576  0
evdev                  24576  1
snd_bcm2835            32768  0
spi_bcm2835            16384  0
i2c_bcm2835            16384  0
snd_soc_bcm2835_i2s    16384  2
fixed                  16384  0
uio_pdrv_genirq        16384  0
uio                    20480  1 uio_pdrv_genirq
sg                     28672  0
snd_soc_rpi_proto      16384  0
snd_soc_core          188416  3 snd_soc_wm8731,snd_soc_bcm2835_i2s,snd_soc_rpi_proto
snd_compress           20480  1 snd_soc_core
snd_pcm_dmaengine      16384  1 snd_soc_core
snd_pcm                98304  6 snd_soc_wm8731,snd_pcm_dmaengine,snd_soc_bcm2835_i2s,snd_bcm2835,snd_soc_core,snd_soc_rpi_proto
snd_timer              32768  1 snd_pcm
snd                    69632  6 snd_soc_wm8731,snd_compress,snd_timer,snd_bcm2835,snd_soc_core,snd_pcm
i2c_dev                16384  0
i2c_bcm2708            16384  0
ip_tables              24576  0
x_tables               32768  1 ip_tables
ipv6                  434176  28
alsamixer is configured such that:

[*]Mic set to L R CAPTURE
[*]Mic Boost both set to 100
[*]Capture - Set to 100
[*]Input Mux set to Mic

Image

Any thoughts as to why this isnt working?

jmiggal
Posts: 1
Joined: Wed Jun 05, 2019 3:42 pm

Re: WM8731 Output working, no input?

Wed Jun 05, 2019 3:44 pm

I have the same problem.
Did you come up with a solution?
Regards

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