# Foss Digital Audio Mixer

**URL:** <https://discourse.zynthian.org/t/foss-digital-audio-mixer/9881>\
**Category:** Related Projects\
**Created:** [August 1, 2024, 12:03pm UTC](https://discourse.zynthian.org/t/foss-digital-audio-mixer/9881 "2024-08-01T12:03:43Z")\
**Posts on this page:** 4\
**Page:** 2

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**Author:** ![le51](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/le51/32/1706_2.png) [@le51](https://discourse.zynthian.org/u/le51)\
**Post date:** [October 8, 2024, 11:15am UTC](https://discourse.zynthian.org/t/foss-digital-audio-mixer/9881/21 "2024-10-08T11:15:07Z")

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Well, I don’t know where these 10 channels should come from !

The Pi 5 has 4 I2S standard stereo DIN (on GPIOs 20 as usual + 22 + 24 + 26 TBC(\*1) and DOUT (on GPIOs 21 as usual + 23 + 25 +27 TBC(\*2))  
I2S0 should be used when Pi5 is clock producer, I2S1 when clock consumer.

Also, while looking at rpi-simple-soundcard.c driver (this file replace the old “simple-card”), I found this:

> <https://github.com/raspberrypi/linux/blob/rpi-6.6.y/sound/soc/bcm/rpi-simple-soundcard.c#L262>

Will an hifiberry\_adc8x arrive soon ?

For some unknow reasons the Pi4 wasn’t able to do TDM, but now we have multichannel I2S on the Pi5.  
Life is cool !  
But I found this recent discussion (started the 9th of September) for adding support of pcm3168, still a WIP:

[https://forums.raspberrypi.com/viewtopic.php?p=2256292&hilit=pcm3168#p2253544](https://forums.raspberrypi.com/viewtopic.php?p=2256292&hilit=pcm3168#p2253544)

and it looks like the guy is going in the TDM way 🤔

yes it is confirmed:  
.1 (this one is from last month)

> <https://github.com/raspberrypi/linux/blob/rpi-6.6.y/arch/arm/boot/dts/overlays/hifiberry-adc8x-overlay.dts>

and  
2.

> <https://github.com/raspberrypi/linux/blob/rpi-6.6.y/arch/arm/boot/dts/overlays/hifiberry-dac8x-overlay.dts>

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**Author:** ![Baggypants](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/baggypants/32/1911_2.png) [@Baggypants](https://discourse.zynthian.org/u/Baggypants)\
**Post date:** [October 8, 2024, 11:59am UTC](https://discourse.zynthian.org/t/foss-digital-audio-mixer/9881/22 "2024-10-08T11:59:08Z")

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> [@riban](#):
>
> Best case would be 20 inputs and 20 outputs but I fear not. Worst case is 6 inputs or outputs. I think the truth lies between them.

13!

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**Author:** ![riban](https://discourse.zynthian.org/user_avatar/discourse.zynthian.org/riban/32/2331_2.png) [@riban](https://discourse.zynthian.org/u/riban)\
**Post date:** [October 8, 2024, 12:14pm UTC](https://discourse.zynthian.org/t/foss-digital-audio-mixer/9881/23 "2024-10-08T12:14:16Z")

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The HiFiBerry configs suggest common bit and word clock pins and individual data pins for each of 4 x stereo inputs and outputs which, assuming it works would give 8 in and 8 out using 4 x 2 x I2S interface chips. That looks cool and is worth trying. I would expect HiFiBerry to produce the cards. They already have the DAC8 available.

I haven’t looked in detail at the TDM option yet.

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**Author:** ![wanthalf](https://discourse.zynthian.org/letter_avatar_proxy/v4/letter/w/ed655f/32.png) [@wanthalf](https://discourse.zynthian.org/u/wanthalf)\
**Post date:** [October 8, 2024, 11:14pm UTC](https://discourse.zynthian.org/t/foss-digital-audio-mixer/9881/24 "2024-10-08T23:14:22Z")

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Just a link to the other thread where @marcus sent some [useful links](https://discourse.zynthian.org/t/dfrobot-dac-audio-decoder-board-for-raspberry-pi-3b-4b/10267/4) on this board!

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