[Infinitas]: USB Audio Class 2 Interface, 32 in, 32 out, DSP

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becario, I have added the missing things. It should now build.
Background: Due to the license of XMOS, I cannot commit the whole workspace/framework and have to filter out my changes by hand for committing only them.

R.
 
The sources of the project are now officially released!
Please visit www.freedsp.cc for it.
The boards related to this project are Infinitas and AnalogIO-x8.

R.
 
Wow, looks amazing. I have some questions though... first one is if this is a suitable project for me if I've never soldered smd and only programmed a tiny bit of java.

The other question is if this interface (conversion quality) is going to sound better than a similar priced retail one. Thanks!
 
bernatvm,

well, it is not so difficult to solder SMDs. You basically need a solder iron with a fine tip. In my GettingStarted tutorials I am giving some youtube links, how to solder the difficult components. Anyway, if you never have done SMDs at all, I recommend to practice with some cheap components first. Soldering some SMDs on these THT/DIP adapter boards is a good way for practicing.

You don't need programming skills to get it up and running. Only if you want to to modifications you need some C skills.

What do you mean with "similar priced retail one"? There are not so many USB interfaces with that high number of channels, and those, that exist are very expensive. Thus, I never ordered one just for comparing.  ;)

R.
 
Hi rkn80,

I am very interested in this project. Good job.
I have a question about monitoring.
Can this interface direct monitoring? And what about the latency if I will set the monitoring in DAW. 
 
Thanks a lot,
Jan
 
Can you specify a bit more what you mean with direct monitoring?

The analog inputs are all accessible on pin headers. Thus, you could make a little mixer board and feed that to a line or headphone out.
If you want to control the direct monitor mix like selecting only a few channels  then you may want to use the DSP for it.
Since this is all done in the hardware itself the latency is very very low but depends a bit on how you implement it.
 
XMOS USB audio stack already contains digital mixer which can be controlled from host via USB.

https://www.xmos.com/developer/published/usb-audio-software-design-guide

See Ch. 3.6 Digital Mixer page 30

Problem is there is no proper application for control, only some command line application:

"The mixer can be controlled from a host PC by sending requests to Endpoint 0.
XMOS provides a simple command line based sample application demonstrating
how the mixer can be controlled."

However, the API makes it possible to route inputs directly to wanted outputs so you can make multiple monitor mixes for an example quite easily.

Edit: The XMOS mixer app sources can be found only on this old version of USB software:

https://drive.google.com/file/d/0B02Djez6mNL2SHhMM0lRSFFBdDQ/view

Look for folder xmos_usb_aud_l2\host_usb_mixer_control

Don't know how to port this app to MacOS or Linux as they have their own USB APIs.
 
Regarding the converters, not mentioned anywhere but I think it is possible to use AK5578 (SNR 121dB) to replace the AK5558 (115dB) but it will cost more ($10/chip).  Also the converters can be paralleled, so you can feed the same input to all A/D channels and get much better SNR (130 dB for the AK5578 and 124 dB for AK5558) for the resulting mono channel.
 
mhelin said:
XMOS USB audio stack already contains digital mixer which can be controlled from host via USB.

https://www.xmos.com/developer/published/usb-audio-software-design-guide

See Ch. 3.6 Digital Mixer page 30

Problem is there is no proper application for control, only some command line application:

"The mixer can be controlled from a host PC by sending requests to Endpoint 0.
XMOS provides a simple command line based sample application demonstrating
how the mixer can be controlled."

However, the API makes it possible to route inputs directly to wanted outputs so you can make multiple monitor mixes for an example quite easily.

Yes, you need to write a software to control the mixing function of the XMOS. I do not restrict that. It is open hardware.  You are free to do that. ;-) But this is more a nice addon.
So far the interface works without any additional software and therefore, I focussed on the hardware. Nevertheless, it should be mentioned that I am already working on a software, that makes routing and controlling (including the DSP) very easy. But the DigitalIO board and the ADAT board have currently higher priority.

R.
 
Regarding AK5578:
I took a short look on the datasheet. It seems to be possible, to upgrade with this chip. There might be some small changes in the I2C configuration needed, I have not compared the register values, yet. But I will do that later.

R.
 
I have never tested it, but since only one serial port is needed, it should be possible. Thus, if you have already a FT232 then I would try it first before buying a FT2232.
 
rkn80 said:
becario, did it work  with the FT232?

Hi.

I do not know yet . On Friday I received the printed circuits and now I have to mount them.
az8nzl.jpg
.
Diamond programmer detects the FT232RL, but it is necessary to check if it really programs it.
5tryo5.jpg

Regards

Jose

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OK, good.

Let me know if you have any troubles with building it.
Since you are the only one who bought PCBs yet, this will show wether the documentation is good enough for sucessfully building an Infinitas.

Raphael
 
Ok, i will do.
I think I will not have problems when it comes to building it, with the documentation provided I think that is enough.
thanks  for the support.

Regards
Jose
 

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