Using OrangePi Zero2 as an equalizer between USB source and USB DAC

[Honza]

Chybí vám git - píše to přímo v terminálu - git: příkaz nenalezen. Protože nemáte žádný git, logicky příkaz git nemohl načíst úložiště camillanode. Nainstalujte git pomocí apt.

Díky za pomoc. Promiňte, narodil jsem se v roce 1959 a jsem v Ubuntu nový.

Translated by Moderators: (Please use English going forward. Thanks)

“Thanks for the help. Promete, I was born in 1959 and I am new to Ubuntu.“

 

[phofman]

Well, honestly that is the problem with projects which may look like trivial, just running a list of commands. But in fact almost always the list assumes some prior knowledge, some prior software to have installed etc. These are complex projects which do require some knowledge.

 

[10PSPMemSticksForMiku2007]

Cool project. Can you use this board to receive 8 channel input over usb and output it with hdmi with no perceptible latency?

 

[alfred_j_kwack]

Hi IAtaman, one thing I realized is that you don't really have to have the GUI running on the device at all. The GUI has to be served from somewhere sure, but it could be served from anywhere really. Since the web brower is making the connection to the DSP and not whatever is serving the GUI webpages that can even be something out on the internet. Not having node running saves you a few cycles on the device if you're squeezed. I suspect you could get GitHub (gh-pages) to serve up the GUI directly if you spent some elbow grease on it (maybe lots of elbow grease though because of http/https and ws/wss constraints). The one compromise you _might_ have to make with a mostly static hosting strategy is with regards to saving pipeline configurations to disk (though you could use the browser's localstorage as well.

 

[capslock]

Seems the Zero 2W is becoming scarce and expensive. The cheapest I could find it at was $24 + $10 shipping. Same for the 3, and the 2 was unobtainium. Are there other boards with similar Armbian support?

 

[IAtaman]

Hi IAtaman, one thing I realized is that you don't really have to have the GUI running on the device at all. The GUI has to be served from somewhere sure, but it could be served from anywhere really. Since the web brower is making the connection to the DSP and not whatever is serving the GUI webpages that can even be something out on the internet. Not having node running saves you a few cycles on the device if you're squeezed. I suspect you could get GitHub (gh-pages) to serve up the GUI directly if you spent some elbow grease on it (maybe lots of elbow grease though because of http/https and ws/wss constraints). The one compromise you _might_ have to make with a mostly static hosting strategy is with regards to saving pipeline configurations to disk (though you could use the browser's localstorage as well.

Hello! Yes, that is true - GUI can run anywhere. I did in fact had a web domain which run the GUI which you could use to control CDSP. There were very few users though so I stopped it.

 

[IAtaman]

Seems the Zero 2W is become scarce and expensive. The cheapest I could find it at was $24 + $10 shipping. Same for the 3, and the 2 was unobtainium. Are there other boards with similar Armbian support?

There are a few more, like Rock Pi S for example, but they are all very expensive these days, I presume due to AI data center investment sucking all the hardware capacity.

 

[capslock]

Thanks. Funny that those little boards that draw mainly on components for settop boxes should be affected by AI center investment.

So is your installation script updated for the Zero 2W or would I still need to change a lot of things by hand if I got a 2W? The 2 is really hard to find these days.

And most importantly, is the 2W capable of doing a three or four way stereo XO, i.e. 8 channel USB out? I guess if there were limitations on the output sample rate I'd be fine with resampling the 2 channel USB in to 24 bit / 48 or 96 kHz and then having the output at 24/48 or 96 anyway.

 

[somebodyelse]

There are a few more, like Rock Pi S for example, but they are all very expensive these days, I presume due to AI data center investment sucking all the hardware capacity.

I hadn't realised how much the prices had gone up, although it shouldn't have been a surprise given what's happened with Raspberry Pi. FriendlyElec NanoPi Zero2 perhaps? I wouldn't expect a need for more than 1GB RAM in this use case.

 

[somebodyelse]

Funny that those little boards that draw mainly on components for settop boxes should be affected by AI center investment.

It's affecting anything made on the smaller process node lines as production time on those lines changes to the higher margin chips for AI stuff. RAM and SSDs were just the first to spike as they're useable directly. Other stuff is going up more slowly based on how much stock there is in the supply chain. Also HDDs - major manufacturers have already sold all their production capacity for this year and most of next.

 

[capslock]

Interesting, H616 is 28 nm, so really old lithography. Prices are getting ridiculous. This was the cheapest offer, and I believe it had $10 shipping yesterday. Look at shipping today. And when you select other shipping options, it get's more expensive. I am not asking for the machine that makes them to be shipped.

 

[capslock]

There are a few more, like Rock Pi S for example, but they are all very expensive these days, I presume due to AI data center investment sucking all the hardware capacity.

It seems I located a 2 (non W) with 1 GB except that the seller is away for another week. It the 2 preferable to the 2W or does it no longer make a difference because you have updated the script?

 

[IAtaman]

It seems I located a 2 (non W) with 1 GB except that the seller is away for another week. It the 2 preferable to the 2W or does it no longer make a difference because you have updated the script?

Hello. Zero2 works fine however Zero2W does not seem to have OTG support, so will not work as an audio input device connected to your computer.

 

[alfred_j_kwack]

Hello. Zero2 works fine however Zero2W does not seem to have OTG support, so will not work as an audio input device connected to your computer.

OrangePi Zero2W does have OTG, what it does not have is DMA (Direct Memory Access). For low‑rate, low‑channel‑count work (e.g. mono or stereo at 44.1/48 kHz with modest processing), you can usually run fine without DMA if your code and buffering are sane. For higher sample rates, multiple channels, complex filters, or tight latency constraints (e.g. guitar FX pedal with sub‑10 ms round‑trip), DMA becomes very useful to avoid dropouts because it stabilizes timing and frees CPU cycles for DSP instead of shuffling samples.

For a Pi‑class DSP use case

• CPU horsepower on an Orange Pi / Raspberry Pi‑class board is ample for quite a lot of DSP (EQ, crossovers, room correction, some convolution) even if the I/O path is PIO/interrupt‑driven rather than DMA.
• The main risk without DMA is buffer underruns/overruns under load, not “insufficient raw compute”; you can mitigate this by:
  • Using reasonably sized audio buffers (e.g. 128–1024 frames depending on latency tolerance).
  • Keeping other system load low and using a real‑time or low‑latency kernel and priority for the audio thread.
  • Avoiding heavy context switching and background jobs on the same core.

All this to say: It's feasible, with caveats.

 

[phofman]

That's interesting, by specs both SoCs (Allwinner H616 and H618) use the same Synopsys DWC2 USB-OTG IP with the same DMA support. IIRC from playing with the DWC2 on RPi DMA can be enabled/disabled in dwc2 configuration and enabling it did not seem to make a difference. A difference was when increasing rx buffers https://github.com/raspberrypi/linux/issues/3447