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TMS320C6748: Active Noise Cancellation Project

Part Number: TMS320C6748

Hi,

I am doing an Active Noise Cancellation project. My requirements are similiar to another question, here is the link:

https://e2e.ti.com/support/dsp/tms320c6000_high_performance_dsps/f/115/t/561587?keyMatch=active%20noise%20cancellation&tisearch=Search-EN-Support

except that I have a specific process time requirement:

        The first path in our program is 3m away from the quiet zone. The sound speed in air is around 340m/s so we have to finish the process in 8 msec.

We prefer to use LCDK to finish our project.

So my question is:

       (1) Is the kit fast enough to finish the transmition and processing in 8 msec?

       (2) How to solve the input problem? The board has 1 line in and 1 mic in. My project need two real time mic inputs. Can we make it on this board?

If the LCDK can't meet the requirements, can you recommend another for this project?

Thanks for your support and hoping to receive a reply from you soon.

Regards,

Li.

  • The team is notified. They will post their feedback directly here.

    BR
    Tsvetolin Shulev
  • Thanks.
    Look forward to the reply.
  • Refer to the acoustic Echo cancellation TI Design document thaat is linked from here for reference:
    e2e.ti.com/.../651326

    DSP Soundware had achieved an AEC setup with the C6748 LCDK platform. We have several third party solution with AEC solutions but you will need to look at their technical documents to look at their process times.

    On the LCDK board, to connect a mic you need to connect the MIC BIAS, which i think is floating. I beleieve the DSP Sound ware team had used splitter cables and connect the microphone for the purposes of testing but for complete hardware setup, you may want to look at the TI design.

    Regards,
    Rahul
  • Hi,

    Thanks for your reply.

    I have checked the AEC project and it shows that they only need one microphone in the project. However, my project requires two real time mic inputs, one for the noise source and one for the quiet zone. Since the kit has two inputs : one is mic in and the other one is line in. Can I connect a mic to line in port directly or do I need a switch or something?

    Look forward to your reply.

    Regards,
    Li
  • Li,

    You can refer to the schematic for the LCDK to look at the audio inputs. The schematics should be part of the package that was delivered with the LCDK, or you can get them from the board vendor.

    All the Line In / Line Out (J10) and Mic In (J11) are stereo connectors.

    You cannot use the Line In and Mic In ports at the same time, but you can use the Left and Right channels of the Mic In or Line In connectors.

    Regards,
    RandyP
  • Hi,

    I check my board and there are 2 inputs(mic in , line in) and 1 output (line out) . Either input can work with output at the same time, which meets my project requirements. But my problem is if I can have two mic inputs

    work simultaneously. That's the key part in my problem. Can you solve this question for me or recommend me a new board if this won't work one LCDK.

    Regards,

    Li.

  • Li,

    Do you have the schematics for the LCDK? You can refer to those to examine and understand the stereo audio inputs.

    You can use the Left and Right channels of the Mic In connector to achieve your requirement.

    Regards,
    RandyP
  • Hi,

    I have the schematics and it shows that there is only one mic input.

    I think I kind of understand your solution. You want me to split one mic input to 2 inputs. And one of the mics connects to the left channel of the original input, and the other one connects to the right channel? Correct me if I am wrong.

    Thanks for your solution. I think it works according to the code example in the library. But we can't get the mic switch. Can I buy one in TI because I can't find it on ebay.

    Look forward to your reply.

    Regards,

    Li.

  • Yes, your understanding is correct regarding splitting the microphone input. TI doesn`t provide audio slitter as far as I know. For setting up the design, we ordered cables from third party vendor. You may be able to find this on Amazon or some other online retailer.

    Regards,
    Rahul