analog&digital together input problem

Hello Eden-chen,

Yes, you can bring in signals from the ADC inputs and bring in signals on the serial port and use them both in the DSP. Then you can send signals out of the serial port and out of the analog port at the same time. Lots of flexibility.

Can you attach your project and let us know some details about the serial data. You mentioned I2S so I assume it is proper I2S in that it is stereo and the data is delayed by one BCLK period. Etc.

So what is the sample rate? Who is the master for the clocks?

Are you using an evaluation board?

Dave T

Also, I noticed you have two posts for this question. If you can delete the other one that would be good. Otherwise, I can let the moderator know and he/she can delete it.

Hello DaveThib,

Sorry for my duplicate posts,it probably bacause my slow network speed. But it was deleted.

Thanks for your quickly reply.

My project summary.

Analog input from local audio port AUX and MIC and stereo digital input from Bluetooth(below call it BT) A2DP. BT audio via I2S streaming to 1701 sdata in0. BT audio always SRC to 48KHz sample rate in BT chipset DSP.

In ADAU1701 mix analog and digital input then output from DAC0/1/2/3,there is no digital output.

When there is no BT audio,I2S clock is stop and only analog input to 1701 ADC0/1.

Now the problem is when I finish to set I2S input(select BCLK&LRCLK&data in0),there is no any audio out from DAC0/1/2/3,I'am sure there is signal into to 1701 ADC0/1.

please take the attached code.

Thank you

Hello Eden-chen,

Thank you very much for your project. It helped me to see what you are doing and where the problem is.

The serial port on this part is a little different in that the serial input is always a slave. The "Master Mode" is only for the output port to be a master or slave. So you will need to set the serial output to master mode in your project. It is a check box in SigmaStudio.

Then you need to set MP10 and MP11 to the "In Lrclk_out" and "In Bclk_out" settings.

So after that you will have the clocks on the MP10 and 11 pins. These clocks will need to go to the BT module but also they will need to be connected to the "Input Lrclk_In" and "Input Lrclk_In" pins. So that the input serial port will get its clocks.

I tested this here and was able to get audio into the port using your project once I made the changes..

Thanks,

Dave T

Hello Dave Thib,

Thank for your detail answer.

In my project BT as I2S master and output Lrclk & bclk to 1701, in this way I still need to set the serial output and link lrclk_in &bclk_in to the output pin Lrclk_out & Bclk_out in the outside circuit?

Anyway I will try it on my new PCB later. Thank you