how to wire an external DAC and to make it output some sound using an app made with sigma studio 4.7

Hello iravelo,

We have to make sure if the serial output port 2 is set up properly, so please attach your project.

If you are confident with your register settings, then probe the serial output port 2 and see the I2S signal and send us the scope pictures. I assume the DSP is the serial clock master.

Regarding the DAC, where is MCLK to the DAC coming from? Are you using DSP's CLKOUT pin? if you are, then well and good. No problem there.

what's the sampling rate? and how are you programming the DAC?

Are you sure about the DAC if it's up and running?

it must be really simple that we are missing here, so give us some info. we will be able to solve this.

iravelo said:

how to build a .dspproj app to handle that external DAC ?

Since this is not ADI's product, SS doesn't have a DLL for this. But you can create an XML file with the DAC's registers and program it from the master control port of the DSP. The below page shows how to do that.

Go to bottom of this page.

Regarding the wire connections,

If the DSP is sending out the MCLK to the DAC then,

DSP                                   DAC

CLKOUT      ------->          MCLK

BCLK_OUT2     ----->       BCLK/SCLK

LRCLK_OUT2   ----->       LRCLK/FRAME_SYNC

SDATA_OUT2 --------->    SDATA_IN/D_IN

GND<--------------------------->GND

Regards,

Harish

and here is how run the wires between the 2 boards, red one goes to +5V (on a third board), at the other side on the connector, the blue one goes to ground, and so on.. 

Hello iravelo,

Thank you, Best wishes to you too!

It seems you got confused with serial port channels.

You are sending 3 stereos out from the DSP. Here is the breakdown.

The channel 0-1 and channel 4-5 (SDATAIO) belong to serial output port 0 which are already connected to the on-board CODEC (DAC side), so you will get the analog out at jack J12 (OUT1) and J13 (OUT2) respectively.

Here is where the problem lies, you mentioned you use serial output port 2, but no channels were there in the schematic which belong to port 2, Rather you configured channel 46-47 which belong to serial output port 3 but stereo is not applicable on those slots even in port 3. So, the output from the core will be ignored, the serial port doesn't acknowledge it.

please have a look at the below table.

So, if you want to use stereo in output port 2 then channel 32-33 (primary) and ch 36-37 (SDATAIO) can be used.

if you want to use stereo in output port 3 then channel 40-41 (primary) and ch 44-45 (SDATAIO) can be used.

Your hardware connection seems correct; you have correctly connected the serial output port 2 pins to DAC, but you didn't select the correct channels in the schematic.

I have modified the outputs in your project, please give it a try.

1467-01jan2026-a07Max-antal_mod.dspproj

fantastic ! i gonna download the fixed project soon...

as expected, using the modded dspproj of yours, I hear things out of the external dac's 3.5mm socket, thanks a lot !!! you are great.

for the record, my adau board is revision B.

let me make sure I fully understand table#36:

- there are a total of 4 serials (out0..out3) and 48out channels

- not all 48channels are available as stereo pairs, these 8 can form stereo pairs : 0+1, 16+17, 32+33 & 40+41

- addtionnal 8 others could be used : 36+37, 44+45, and x+y, z+t

So if I want to use a 2nd external stereo dacs like my pcm1502 before, should I then connect that one to out3 pins of the adau board and use channels 40+41 in SS ?

and what if I wanted to wire a total of 4 external stereo DAC ?

cheers.

Hello iravelo,

Let me put it this way. 

For stereo,

There are four serial output ports, and each port has its primary stereo channels (0-1,16-17,32-33,40-41).

and there are 8 SDATAIO pins and if you want you can configure all 8 pins as outputs, now you have to map these 8 output pins (SDATAIO) to the serial output ports.

Port 0 supports 3 SDATAIO stereos (4-5,8-9,12-13).

Port 1 supports 3 SDATAIO stereos (20-21,24-25,28-29).

Port 2 supports 1 SDATAIO stereo (36-37).

Port 3 supports 1 SDATAIO stereo (44-45).

Now, you can configure the SDATAIO registers to follow a serial port and transfer stereo output using SDATAIO pins.

with primary and SDATAIO pins (as fully outputs), you can transmit 12 stereo signals.

The same channel slots apply for input side too. You can also use all these 8 SDATAIO pins as stereo inputs.

This is a general explanation for others using a custom board.

For the Eval board,

4 SDATAIO pins out of 8 SDATAIO pins are used up. one as input and three as outputs.

SDATAIO4 is used as an additional stereo input following serial port 2 clocks. The channels are 36-37.

SDATAIO5 is used as an additional stereo output following serial port 0 clocks. The channels are 4-5.

SDATAIO6 is used as an additional stereo output following serial port 0 clocks. The channels are 8-9.

SDATAIO7 is used as an additional stereo output following serial port 0 clocks. The channels are 12-13.

Now in the eval board, the SDATAIO0,SDATAIO1,SDATAIO2,SDATAIO3 are available in the headers. please refer the schematic, that you can configure as input or output.

Note that these SDATAIO pins also have MP functions.

Let me know if you have any questions.

Regards,

Harish

thanks a lot, I think I got it,

bye the way, the pcm1502A being a simple board used to understand/validate the process. Now I switched to one of my target boards, having an ESS9039q2m and dual OPA1612 in its output stage, the connection is like enclosed..

thanks a lot, I think I got it,

bye the way, the pcm1502A being a simple board used to understand/validate the process. Now I switched to one of my target boards, having an ESS9039q2m and dual OPA1612 in its output stage, the connection is like enclosed..