ADAU1701: is 44.1Khz a supported rate for the I2S Serial Data Input?

Hello,

You can run your ADAU1701 at 44.1K by providing a 11.2896 MHz MCLK instead of 12.288 MHz. This needs to be synchronized with the I2S to/from your Teensy, because the -1701 lacks a ASRC (Asynchronous Sample Rate Converter). If the Teensy can supply this 11.2896 MHz clock, run the -1701 as a I2S subordinate. Or if the Teensy is capable of accepting an external MCLK, use a 11.2896 crystal with the -1701 and make it the MCLK source. If you run your Teensy and -1701 with independent clocks, audible artifacts result -- connecting the I2S clock lines alone is not sufficient. More advanced SigmaDSPs such as the ADAU1452 avoid this limitation by including ASRCs. Please see this post for more information.

Best regards,

Bob

Hi Bob,

Okay that's nice! The Teensy indeed generates the main clock for the ADAU1701 and also at the right frequency as far as I can tell (I have a very old analog scope which doesn't do measurements so it's a bit of guesswork). The BCK and LRCLK are also running but the DATA lines (in and out) are completely quiet. I did set the register settings such that the auxiliary input accept SDATA.

Hmm, I do have a question: when you export a sigmaDSP project to hex (and header files), do the register settings also get exported as part of this? I'm using this repository for the export scripts:github.com/.../SigmaDSP

This is what my register settings look like btw!