I have contacted Nick from WAFaudio, designer of Najda. Najda is peace of hardware, like any other DAC.
This is Nick respond on my question about kernel ;
There's no such thing as a kernel for the Najda. The concept of kernel doesn't apply to the Najda.
They probably want to know what signals the I2S port can accept. Please refer to the Startup Guide (Expansion 1 section). It's slaved I2S, two 32-bit slots per sampling period, data aligned to the left.
I hope this helps...but I think this is the sime as any other requerments for I2S input DAC
As I can't provide any better info about Najda, I will keep my eye on 0.3 and hope that some profile will work with Najda DSP.
this is from Najda manual
In order to connect an external I2S stereo source to Najda, follow these simple steps:
–
Your device's Data Out → I2S_EXT1_LINE1
–
Your device's FSync (or L/R) → I2S_EXT1_FSR
–
Your device's SCLK (or BCLK) → I2S_EXT1_CKR
Tie IS_EXT1\ to DGND
Don't forget to wire the ground, ideally one separate ground line per signal.
Pin IS_EXT1\ is useful for letting the micro know whether there's an external I2S source on this
port. If you don't use such a source, leave this pin open and the micro will not offer I2S Port 1 as an
input source option in the menu, thus avoiding the unpleasant pop in your speakers while sweeping
across source options.
On the other hand, if you intend to use a I2S source, make sure to tie IS_EXT1\ pin to DGND
otherwise you're not going to be able to select this source.
The source connected to this port acts as the master. All pins described in the connecting procedure
above are inputs to Najda. You don't need to worry about sampling frequency as data goes through
the sample rate converter.
This port is nominally 3.3V TTL and 5V tolerant, so it should cope with the vast majority of I2S
sources without the need for any level conversion circuitry.
Data format is the most common, i.e. 64 bit clocks per sample period in 32-bit time-slots, with data
aligned to the left.
