The carambola specs specify that it is possible to use I2S (not I2C) with Carambola. I have a few questions about this.
I have only found examples of people using carambola with SPI or I2C, but not I2S. Is it possible to use
SPI as well as I2S at the same time?
My idea is to use Carambola in combination with an audio grade DAC in order to build a
wireless MP3 Player / Internet radio, hence I would have to add hardware
to output PCM samples and optionally also an SD card through SPI(which I've seen people got working)
My dac of choice would be the TLV320aic23b

Has anyone here used I2S on carambola and could share their experiences?
I'd very much look forward to hearing from you.

Thanks,
Nik

If I2C and I2S don't share the same ports you could of course use them both at once.
I haven't looked into I2S, but usually the specs are very similar to I2C so most controllers that can do I2C & I2S share common Ports for that, so those won't do I2C and I2S at once (have a look at the datasheet of the Ralink SoC for the Carambola, it'll tell you everything you need to know about the I2* interfaces).
As far as I could gather from the forums nobody has gotten decent read speeds from SD over I2C, so I don't know if the current solutions for SD over I2C would be sufficient for a MP3 player.
Although if I was going to build a MP3 player from a Carambola I'd use the USB port for storage media access (it's so much more practical to be able to chose from the wide range of USB storage media options).
As for the audio output, you can also use a USB sound card. Those are very small and work out of the box with Carambola (at least after you've compiled an image with usb audio support) and they're cheap, too.

The required USB parts for your project would fit in a tight space, so chosing between the USB version and the I2* version is a question of whether you want a (possibly hard) learning experience or a quick way to a solution.

I'm interested in this as well. I'd prefer a native i2s solution over the USB solution.

To be honest, I've got an interest in native i2s as well, because most of the USB sound cards out there will only deliver CD quality audio.
I've got an audio project that requires a much higher audio quality (at least 96kHz@24Bit) and could benefit from the processing power (and interfaces) of the Carambola. But I guess for that project I'll have to stick to the Cortex M4 for now.

Thanks for your replies!

I've run into some complications as to finding I2S in the datasheet. While I am able to find the data registers and pins for the interface, I am unable to find any description of how to set up I2S with the right sampling frequences, clock outputs etc.
Also, I'm having a bit of a hard time finding a description of the software interface on linux to access said registers.

I think I will also have stick to other controllers, which is a shame because I really like the WiFi capabilities of Carambola.
All other WiFi Modules that I could find and that have an openly accessible description of their API seem to be quite slow (2Mbps tops)

Hi NaYthan

I recently "Found" the Carambola and ordered the full unit with case.
My idea is also to build a "Wifi Radio". I had a look into I2S but i think i am going the I2C route, brave or stupid... not sure yet..
I have ordered a VS1053b board that i plan to use.

Z69

Any news about I2S implementation? Maybe it is possible to get Ralink SDK for RT3050?