Resending a previous email which was removed from the list archives ...


Yes you can,

I did a test setup with a stereo card, however it should also work with the octo in the same way. You need to enable both HDMI audio and the sound card at the same time.

Once you alter the /boot/config.txt file as specified at the end of this message, you should have different ALSA devices specified.

I see the following :

pi@raspberrypi:~ $ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: ALSA [bcm2835 ALSA], device 0: bcm2835 ALSA [bcm2835 ALSA]
card 0: ALSA [bcm2835 ALSA], device 1: bcm2835 IEC958/HDMI [bcm2835 IEC958/HDMI]
card 0: ALSA [bcm2835 ALSA], device 2: bcm2835 IEC958/HDMI1 [bcm2835 IEC958/HDMI1]
card 1: audioinjectorpi [audioinjector-pi-soundcard], device 0: AudioInjector audio wm8731-hifi-0

pi@raspberrypi:~ $ arecord -l
**** List of CAPTURE Hardware Devices ****
card 1: audioinjectorpi [audioinjector-pi-soundcard], device 0: AudioInjector audio wm8731-hifi-0 [AudioInjector audio wm8731-hifi-0]

To make this work, I setup my card as required to record from the microphone, then I do the following :

arecord -Dhw:1 -fdat | aplay

This records from card 1 (the audio injector card) and plays through the hdmi audio device (by default, card 0 is used).

If you have problems with clock skew, then you can use plughw instead of hw as the capture or playback device.

Here is my /boot/config.txt for setting up the stereo card (swap out for your octo device tree below) :

hdmi_drive=2
dtparam=i2s=on
dtparam=audio=on
dtoverlay=audioinjector-wm8731-audio

The "dtparam=audio=on" line enables the HDMI output audio device. I am not sure if the first two lines are necessary, try to remove "hdmi_drive=2" and "dtparam=i2s=on" independently to test if they are required - with reboots in between.

Matt
p.s. Once you have a working system or you have more questions, please let the list know.

On 10/3/20 11:47 am, Glenn Kubota via People wrote:
Hello,
Is it possible to use the Octo sound card for 6 channels of input and also use the Pi HDMI port as the 5.1 output? If so, how can I do it? It seems like I've been able to enable one or the other, but not both.

Thanks,
Glenn

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