How Do I View The FFT Output Data In Sigma Studio (ADAU1452)?

Hello,

Sorry for the delayed response.

We would suggest you to refer the below Ezone thread which contains detailed explanation about FFT.

https://ez.analog.com/dsp/sigmadsp/f/q-a/66000/adau1452-fft-library

Regards,

Lalitha.S

Hello,

Unfortunately there are no information about how to display the FFT results (energy in each band/block).

Is it possible to display them or to save them for analysis ?

Best,

Mathieu

Hello Leyas,

Unfortunately there is no way of getting the FFT results from SigmaStudio. The other way around is , If you have a MCU then you probably could read the memory of that block and get the FFT data.

Regards,

Harish

Could you explain, how to read FTT blocks from an MCU? , wich adresses. how to read. Thanks

Hello,

The FFT result is output to buffers which ping-pong every block size boundary. For example for a 128 FFT at 48kHz the buffers swap every 2.7 mS. You would need a signal/interrupt to synchronize to the swap and use the correct ping-pong buffer address to read the result correctly. You need to implement framework override to add code to generate a sync signal, for example modify the block start code:

<blockstart>
/******************************************************************************
* XML Cell Block Start Code
******************************************************************************/

__Block_Program_Start__: nop;

// Toggle a GPIO to signal start of block processing

</blockstart>

Anyway this is a very tricky process and you need to find the correct ping-pong addresses which may not valid due malloc/free operations which reuse buffers

Hello,

Would it be possible to provide more information regarding how to perform the framework override required to add code for sync signal generation? Any feedback is greatly appreciated.

Hello rmyers,

Sync signal generation? You mean clocks? Sync what to what? Framework override? For what reason?
Can you start a new thread as a new post and add a lot more detail as to what you want to or need to do. It seems like your question does not exactly fit into this thread.

These parts, and SigmaStudio, is so flexible for clocking and for generating signals on an MP pin that I think you should be able to do this without any framework changes.

Thanks,

Dave T

Hello Dave,

Thank you for the feedback and apologies for the lack of information in the previous post. The question about framework override was intended in the context of ChristopherH's post regarding extracting FFT output data to an MCU, specifically the following statement:

You would need a signal/interrupt to synchronize to the swap and use the correct ping-pong buffer address to read the result correctly. You need to implement framework override to add code to generate a sync signal.

I can start a separate thread related to the question of how to extract FFT results to an MCU if that is preferred.

Thank you,

Ross Myers