Hello,    My name is Anna and I am currently a senior in college. I am in engineering design and my team was given a task that requires us to create an active noise-cancelling device. After some research, my team decided to purchase an ADAU1701 DSP from An

Heres a description of my problem:

Hello, My name is Anna and I am currently a senior in college. I am in engineering design and my team was given a task that requires us to create an active noise-cancelling device. After some research, my team decided to purchase an ADAU1701 DSP from Analog Devices because it can be used in active noise cancellation. We also purchased a microphone, ADAU1701 DSP adapter socket to attach DSP to a breadboard, audio amplifier, speaker, power supply, and USBi JTAG programmer. We are having trouble using SigmaStudio 4.7 to program the DSP using the USBi JTAG. Is there a way to use the USBi JTAG to program the DSP? Thanks for your time, Anna

Hello Anna,

Glad you are using one of our SigmaDSPs for this project. You are going to learn that this DSP will not be suitable for an ANC application unless it is only very low frequency noise you are trying to remove. The reason is that the latency is too long with the converters. The DSP also is limited with the amount of processing it can do. This still will be a good learning exercise. If I were your professor I would still see the value of this exercise and I would want to see an explanation for the limitation in the final report.

You can do an ANC application with the ADAU1452/1467 family of parts but you need to use low latency converters. The best part for this will be the ADAU1787 which was designed for ANC applications.

Back to your question. You mentioned USBi JTAG. Are you using one of our USBi interfaces or an after-market version?

Also, have you found my YouTube channel?

Thanks,

Dave T

Hello,

Thanks for your response! So are we not going to be able to make an ANC with our ADAU1701 DSP?

We are using a USBi JTAG that we found on Amazon.

I have not found your Youtube channel.

Thanks,

Anna

Hi Anna,

David's YouTube channel is at:

https://www.youtube.com/channel/UCHFzVRIj3YoH1Vdt866BZHw

and is extremely helpful for those new to SigmaStudio. He is correct about the -1701 in, for example, noise cancelling headphones or a similar device where you wish to cancel external noise by feeding a canceling signal to your transducers. The difficulty is that the in-out delay (latency) of the ADAU1701 totals approximately 1.1 mS -- thus as you approach 450 Hz, your cancellation has been shifted 180 degrees and is now adding to the noise. Thus, as Dave said, the part can only cancel a very low frequency rumble.

If instead you're considering a simple dynamic noise reduction scheme which gates frequency bands according to their level, the -1701 can do this for voice while the -1452 can for music. It's also possible to have a -1701 remove pops and clicks from vinyl records. Search this forum for these project ideas. A college student studying music once even built an ultrasonic assist device for his blind friend with a -1701. Whatever chip you end up using, the more your team experiments and learns with it, the more you can do with it.

Best regards,

Bob

We are using the DSP to decrease the volume of an oscillating saw. The dominant frequencies are 225 Hz and 3000 Hz.

Our project is due in a week or so and we were wondering if there is anything else we could get quickly.

Anna