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Re: External Audio DSP Processor Project

Posted: Mon Oct 04, 2010 4:38 pm
by Folknology
You could add a midi interface easily enough to the XC-!a for control purposes see the midi section in the Audio MC 2.0 reference design I mentioned.

For good audio I/O you may as well add a CODEC rather than a plain DAC it will be better quality and probably cheaper..

For monitoring just build a D-Class output, Xmos have some good code examples for this.

All of that would make it lower cost.

Re: External Audio DSP Processor Project

Posted: Mon Oct 04, 2010 6:49 pm
by lilltroll
Also your chip choice may lead you to using an L2 rather than a G4 as this is already a reference platform for xmos audio see USB Audio 2.0 multichannel ref design. This would provide a good basis for your design as the schematics are already available.
Al
For G4, you can also take a look at the schematics for the XDK http://www.xmos.com/products/developmen ... opment-kit , it has the XTAG&serial FTDI + USB2.0 + Ethernet and a stereo CODEC. If you want to keep it simple, use a CODEC with a on-chip voltage regulation and already existing "drivers" (XC-code).

Re: External Audio DSP Processor Project

Posted: Mon Oct 04, 2010 7:18 pm
by Folknology
Nice one Mika I forgot about the XDK that has some really good references that are applicable to the XC-1A and G4

Re: External Audio DSP Processor Project

Posted: Mon Oct 04, 2010 10:28 pm
by williamk
Thanks guys, I will check this out tomorrow. :mrgreen:

Re: External Audio DSP Processor Project

Posted: Tue Oct 05, 2010 3:31 am
by lilltroll
Here is an other old project:

A MIDI synth with LCD
Image
http://archive.xmoslinkers.org/node/122:

Re: External Audio DSP Processor Project

Posted: Wed Oct 06, 2010 5:48 pm
by williamk
Nice one, thanks. :geek:

Re: External Audio DSP Processor Project

Posted: Wed Oct 06, 2010 10:02 pm
by lilltroll
williamk wrote:Nice one, thanks. :geek:
This one is :ugeek:

http://archive.xmoslinkers.org/node/240

And then play McGyver :mrgreen:

Re: Another project idea: generic usage (audio?)

Posted: Thu Oct 07, 2010 10:50 pm
by paul
williamk wrote:Ah, can this be moved to Project Proposals, please? :oops:
Done!

Re: External Audio DSP Processor Project

Posted: Tue Oct 12, 2010 6:01 pm
by williamk
Ok, some more talk. How hard is to interface with the ethernet (RJ45) via a home-network? I mean, the idea is simple, send a chunk of audio and midi information and collect the last buffer. So it works like this:

1) create small buffer
2) send audio and midi to buffer
3) release

next set of samples

repeat {
1) read previous buffer
2) clear buffer
4) send audio and midi to buffer
5) release
}

Re: External Audio DSP Processor Project

Posted: Tue Oct 12, 2010 7:17 pm
by Folknology
Well for the Ethernet you will need 5 or more threads ( 2 for the Rx and Tx Mii layer and 2 for the Mac Rx and Tx layer) . On top of that you could use TCP/IP sockets which are standard and easy to deal with at the other (non Xmos) end. however on Xmos the TCP/IP code is plain nasty. You could communicate directly over Ethernet using AVB or some such for which standards exist. but basically expect to dedicate a most of the threads on a given core unless Ethernet on Xmos has been thread optimised for AVB in another way compared to the provided Ethernet 1v3, I'm no AVB expert.

On top of that it should just be standard midi, audio and I/O user interface stuff which should be more straight forward.

regards
Al