Evaluation board for ANC application

Hello adolfoe,

The EVAL-ADAU1787Z is a good choice for Active Noise Cancelling (ANC) applications, if you want low latency. It features a low-latency path from analog input to the DSP core and analog output, making it ideal for noise-cancelling. Additionally, it supports the NLMS (Normalized Least Mean Square) algorithm, which is commonly used in adaptive filtering for ANC. The ADAU1787 has 4 ADCs and 2 DACs in-built.

It has a Fast DSP which executes the Biquad filters very fast.

Please have a look at the eval board here for input and output connections and headers for interfacing and the datasheet here

If you want to do a lot of processing, then you can also look at ADAU145x/ADAU146x DSPs which have more MIPS and memory available. These DSPs have Filtered NLMS and MFxLMS algorithms available. But these DSPs need an external codec (ADC/DAC) which will add some latency. You can have a look at the ADAU1452 eval board here.

This thread will give you some more idea on these two DSP families and its capabilities. you can choose one of them depending on your application.

I'm just giving you a basic overview on these DSPs, depending on the latency and other processing requirements, we will discuss this further.

Hardware for Programming/Debugging

To program and debug the SigmaDSPs, you will need a USBi module (EVAL-ADUSB2EBZ), which comes with the eval board kit. This board provides USB-to-I2C/SPI conversion and is compatible with 1.8 V and 3.3 V target devices. It also integrates with SigmaStudio, the primary development environment for Analog Devices' SigmaDSP® processors.

You will get the ADAU1787 DSP, ADUSB2EBZ USBi module and USB cable in the Eval board kit.

Typical IDE and Programming Language

IDE: SigmaStudio is the primary Integrated Development Environment (IDE) for Analog Devices' sigmaDSP products.

Programming Language: SigmaStudio uses a graphical programming approach, where you can design your signal processing flows by drag and dropping blocks and connections. It does not require traditional text-based programming, though scripting can be used for advanced configurations.

License: SigmaStudio is free to download and use; no license is required.

If you have any further questions or need additional details, please feel free to reach out.

Regards,

Harish

Hi Harish,

Thanks for your feedback.

I have some follow up questions.

1)How flexible is the SigmaStudio regarding programming? Is it possible to for example to do the following actions?

* Output white noise signal from the speakers?

* Create algorithms to store filter coefficients for primary and secondary paths, based on the response to the white noise?

2) Does SigmaStudio supports any simuation/emulation capabilities?

Thanks in advance for your suggestions.

Hello adolfoe,

SigmaStudio is reasonably flexible. There is a lot you can do but there are limitations so it is tough to answer. This is a stream based processor not block based so that is where a lot of the limitations are. However, that is also a huge advantage because it is lower latency!

There are plenty of signal sources available in the SigmaDSP core.

Then under the "Filters" section we have a inking filter that will filter the white nose into pink noise.

For this question:

"Create algorithms to store filter coefficients for primary and secondary paths, based on the response to the white noise?"

This gets a little more complicated but the fast DSP core has parameter banks for this very reason.

It is detailed in the datasheet:

The reason for this was to have one filter bank be the active one and be able to make changes and update the non-active filter bank safely to avoid unstable filter configurations until you have updated all the filters, then you can instantly switch over. Then the third filter bank is often used as a bypass but it is entirely up to you.

As far as emulation or simulation. Yes, we have some basic functions to do this. We have a stimulus and probe feature.

This is run from SigmaStudio and NOT on the actual DSP core. So for adaptive filters it is not helpful. This feature was developed on our older cores. You can see the filter response and watch it change in real time on the screen but it is all being calculated in SigmaStudio on the PC. This screenshot I took I did not even have an eval board connected at all.

For adaptive filters it is not very useful because it has no way to pick up the coefficients that are in the core. You will need to be measuring that using external measuring hardware/software.

Dave T