Has anyone tried any external (obviously USB) sound card with Udoo? Some advice, if there's any experience, would be great before I set out to look for one. Thanks
Can I ask why you are looking for an external sound card? I'm trying to work through sound issues with the board and as I understand it the board has a on board sound chip (VIA VT1613). So why do you feel the need for an external sound card? The reason i'm asking as I'm wondering if I've mis-understood the boards capabilities. I'm looking to connect multiple mics/speakers to the board and trying to work out the best way to do that. the i2s bus seems to be promising.
Don't know anything about the i2s bus, I have to admit. I have in mind using an external sound card cause I want to get four DAC channels plus use the ADC, and if I use the built in jack sockets, I'll sure get a lot of noise with the input. At least that's how you do live sound with a laptop, traditionally. Can you give a bit of info concerning the i2s? How many outputs can it provide? Is it noise free (to an acceptable level)? and what's the process to have access to it via Pure Data?
Just to get it out there. I really have no idea what I'm talking about!!! However I've been doing a lot of reading. It looks like there are 2 i2s pins on the board both of which can deliver stereo sound with very low (or no jitter). From what I can tell they are often used to interconnect onboard audio chips such as connecting a sound chip to a dac. The i2s can run either 3 lines (two clocks one data) which will deliver stereo (the second is used to control whether left or right audio is being transmitted). I think it can go up to 24 bit words. If you add two additional lines I believe that it then becomes bidirectional in that the two addition lines are a second clock (left/right) and a data line. I've seen various statements about the distance you can transmit i2s over. I've seen one statement state that 3cm is the max distance yet I'm reading on diyaudio that using twisted pair people have ran cables for 20 or 30 cm (which is more than enough for my application). I've also found 'memes' microphones which will connect directly to an i2s as well as some amplifiers/speaker packages that talk i2c. I suspect that if you are trying to build an audio system that it won't work and the spifd line is what you want. However I suspect that i2c might work for my application (a touch screen deskphone). The i2c to dac/adc idea I guess also makes some sense as I assume i could connect a microphone/speaker directly to the dac/acd. So thats what I have so far and it could all be completely wrong This link might be of intereset: http://volumio.org/forum/i2s-over-hdmi- ... x-t57.html and this http://www.crazy-audio.com/2013/08/high ... using-i2s/
