I have an XR-USB-AUDIO-2.0 (eval) board connected via I2S to an TI DAC.
The PC does not recognize the XMOS board if already connected with I2S. I have realized:
the LRCK matters: if already connected to DAC, never mind if DAC is powered or not, the board is not recognized on PC, as USB device. Often nothing happens or an "unknown device" is reported.
If I let the LRCK open (not connected), I works. I can get it to work if LCRK is open when XMOS board is powered (USB connected), connect LRCK later after PC has realized. If already connected to I2S - it does not work (no USB device or unknown).
Is there any reason (e.g. the LRCK is used as a boot up pin, it checks for input, then another device/behavior selected)? How to fix?
Without any fix, the XMOS is not working for me, sorry to say.
Best regards, Torsten
XR-USB-AUDIO-2.0 with LRCK wired is not recognized
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tjaekel
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Ross
- XCore Expert
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The XR-USB-AUDIO-2.0 board does share LRCLK and SPI_CLK on the same port, so you could have issues booting from flash if the DAC is driving LRCLK or you are attaching flying leads I suppose. The board is intended as a reference platform for people designing their own products, rather than a board to use with various external DACs etc.