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TMS320C6455 DSK audio question

Pete12457
Intellectual 280 points

Hello,

Is there any documents regarding audio processing for C6455 board (how to input, output, and some examples)?

Thanks in advance.

  • 0
    TI__Mastermind 24340 points

    Hi Pete,

    You can go to the spectrum digital web site for C6455 - download and install the Target Content package.

    After you download and install, you can find an audio example at:

    ...\boards\dsk6455_v2\examples\dsk_app

     

     

  • 0 in reply to Mariana
    Intellectual 280 points

    dsk_app is not really what I want since it does not do any sound input and output. I just need an example that allows me to input my voice, as an example, and it will output my voice.

    Thanks.

  • 0 in reply to Pete12457
    TI__Mastermind 18130 points

    The dsk_app project was built specifically around input and output from the on-board AIC23 stereo codec. This project does not do any sound *processing* but if you are only after voice input and output you should be able to plug in a mic and headphones, run the dsk_app project and hear your voice on the output (NOTE: you may need a powered mic, but other than this you should have no issues).

  • 0 in reply to TimHarron
    Intellectual 280 points

    It didn't work with my microphone. I haven't tried with powered microphone but do you mean the C6455 is designed to work with powered microphone only? If not, is there any way to make it work a non-powered microphone?

  • 0 in reply to Pete12457
    TI__Mastermind 24340 points

    To eliminate the microphone "variable", you could play something in your computer and connect the output of your computer to an audio cable, and the audio cable to audio input of the DSK. Connect the output of the DSK to a headset or to speakers. This way you will know if the problem is the microphone.

  • 0 in reply to Pete12457
    TI__Mastermind 18130 points

    Pete said:
    I haven't tried with powered microphone but do you mean the C6455 is designed to work with powered microphone only?

    I haven't studied the design (and I'm not a mic expert anyway) but I believe that is indeed the case. I do not believe that the C6455 DSK is meant to power the microphone as would something else like your PC sound card. If this is the case then I do not know that it would be possible to modify the board to power the microphone . This may be something you want to ask Spectrum Digital as they designed the board.

    In any case I whole-heartedly agree with Mariana's suggestion to try connecting the line out from your PC to the line in on the DSK to ensure proper function. In this case the PC's line out would function similarly to a microphone input.

  • 0 in reply to Pete12457
    TI__Mastermind 41665 points

    Pete said:
    It didn't work with my microphone. I haven't tried with powered microphone but do you mean the C6455 is designed to work with powered microphone only? If not, is there any way to make it work a non-powered microphone?

    The demos typically are designed around the use case Mariana suggests, where you drive a signal into the line in, as opposed to using the microphone input. The AIC23 has an internal mux that can switch between the line input and the microphone input, so if one is enabled the other will not be, also note that as Tim suggests the line input is expecting a stronger signal than a standard mic can provide so if you just plug your mic into the line input you may not hear anything at all. This being said, to have it work with a normal unpowered microphone you would have to modify the code such that you set the INSEL bit in the analog audio path control register (address 0000100) on the AIC23 as discussed in section 3.1.3 of the AIC23 datasheet.

  • 0 in reply to Bernie Thompson TI
    Intellectual 280 points

    Thank you all. I did get the signal from my normal unpowered mic. As Bernie said, there is a INSEL bit that controls whether input from mic or line in. Also, the DSP does accept a normal mic. The signal is weak but I was able to enable the mic boost that amplifies mic signal.