diyAudio

diyAudio (https://www.diyaudio.com/forums/index.php)
-   Digital Line Level (https://www.diyaudio.com/forums/digital-line-level/)
-   -   XMOS-based Asynchronous USB to I2S interface (https://www.diyaudio.com/forums/digital-line-level/188902-xmos-based-asynchronous-usb-i2s-interface.html)

qusp 19th May 2011 01:52 PM

haha, having accidentally short circuited a lifepo4 x 4 pack from a123 i know what you mean!! they really mean business these days, no more can people claim battery power has current limitations

Lorien 22nd May 2011 05:35 AM

Finally, after five insane days servicing air conditioning systems for cars, saturday got some time to play with this card....
Wishing to get rid of any additional source of EMI and switching noise, I choosed (for 1.0V core PSU) the NI LP3879 Linear Vreg. instead of ON-semi NCP1521 1.5MHz DC-DC converter part found on XMOS' reference board. Even if the later one have efficiency up to 95.3% - it's still a switching one.
Taking into consideration the I/O architecture of the XS1-L1 chip, the I2S signals comes directly form it thus it is not necessary to realign these signals to the master clock using FF. Even if XS1-L1 have two sets of PSU (for core and for I/O) I could choose DC-DC converter insted of LP3879 to power up the core and a better Vreg for 3.3V I/Os. Still, all the data processing happen in that chip thus noise can easily propagate. Moreover, that package is big enough to make you think harder at impedance and ground bouncing issues. So, for the sake of I2S signal's integrity, I thought it's better to replace the DC-DC converter with an linear vreg and minimize the noise as much as I can even if the later one is less efficient and comes with a higher price.
BTW, the current rising after replacing the 400 MHz XMOS chip with 500 MHz part was negligible... both works flawless and at the same temperature.

rlim 24th May 2011 01:19 AM

Does your window'w driver put out periodic beeps?

Lorien 24th May 2011 09:43 AM

This board comes with full featured version of Thesycon driver and not the evaluation one thus there are NO periodic beeps whatsoever. In addition, it was digitally signed (kernel mode) to run on 32 and 64 bit Windows OS (including Win 7).
Regards,
L

rlim 24th May 2011 03:00 PM

Where can I get a board with the full-featured driver? It appears that if I were to get the xmos board from digikey, it comes with an evaluation version of the windows driver. Did I get that right?

Lorien 26th May 2011 06:53 AM

This board comes with full-featured driver :) From my knowledge, all XMOS reference boards are shipped with demo driver support, the fully functional one is subjected to minimium order quantities as stated on XMOS site:
"Access to the Thesycon production driver via the bundled part is subject to a minimum order quantity" ... Qs that are >= 90 pcs. depending on the chip you'll use (XS1-L1 in this case).
At the beginning, it was annoying for me to hear periodic beeps so I've changed XMOS board's VID/PID to my own... and now I have get rid of one source of stress.
Regards,
L

nullstring 27th May 2011 04:07 AM

Quote:

Originally Posted by Lorien (https://www.diyaudio.com/forums/digital-line-level/188902-xmos-based-asynchronous-usb-i2s-interface-post2583934.html#post2583934)
This board comes with full-featured driver :) From my knowledge, all XMOS reference boards are shipped with demo driver support, the fully functional one is subjected to minimium order quantities as stated on XMOS site:
"Access to the Thesycon production driver via the bundled part is subject to a minimum order quantity" ... Qs that are >= 90 pcs. depending on the chip you'll use (XS1-L1 in this case).
At the beginning, it was annoying for me to hear periodic beeps so I've changed XMOS board's VID/PID to my own... and now I have get rid of one source of stress.
Regards,
L

Do we have a price yet?
I am trying to decide which USB to I2S interface I want to invest in.
They seem to be popping up all over.

Lorien 27th May 2011 01:16 PM

This board have the promotional price of 99 Euro without shipping and Paypal fees. Shipping costs depends on destination thus it's not a fixed one.
PM me at ekits (at) luckit . biz and I'll send you the total amount.
Best wishes,
L

Lorien 5th June 2011 01:30 PM

I've changed the firmware to display incoming sample rate by using LEDs connected at one of the pin header (J9 - on the bottom left corner of the board).
On the other hand, I'm thinking on a improved version of this board: better PSU will be a "must have". Any suggestion are welcomed!

barrows 6th June 2011 04:53 AM

New Board...
 
Lorien, I guess you are considering a new design to further optimize the power supplies, perhaps? If you mandate an external supply, then I would suggest that adding a shunt regulator to power the clocks. A TentLabs part might be appropriate here, as the high bandwidth, low noise, and low output impedance should allow the best performance of the clocks.


All times are GMT. The time now is 10:02 PM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 17.65%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2020 DragonByte Technologies Ltd.
Copyright ©1999-2020 diyAudio

Wiki