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Compiler: PADK TMS 320C 6727

Tool/software: TI C/C++ Compiler

Hi,

I have been using the PADK - Professional Audio Development Kit, to achieve active noise control for some time now. It is a multiple channel I/O incorporating the TMS 320C 6727 DSP.

However, Im just getting some problems with the ADC input channels. Normally, i connect the output of an electret microphone directly to one of the ADC input channels and the input signals are processed by the DSP. But now as i connect the output of the microphone to the ADC channel (anyone of them is the same), the voltage at the microphone output (sane as that of the ADC input channel)  freezes and the mic no longer works. I have been doing a lot of tests to find out where the issue is. and I think that the problem lies with the ADC input channel. But I am unable to trouble shoot it and if necessary to reset the ADC input channels.

Is anyone aware of that issue? and any solution to that.

Thanks,

regards,

Sajaad

7 Replies

  • Hi Sajaad,

    I've forwarded this to the design team. Their feedback should be posted here.

    BR
    Tsvetolin Shulev
  • Sajaad,

    Is the board a TI EVM or custom board ? Have this board been working properly before this issue ?

    Can you try with another board and check the functionality ?

    Regards,
    Senthil

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  • In reply to SenthilKumar Srinivasan:

    Hi Senthil,

    Thanks for your update.
    The PADK - Professional Audio Development Kit - is a digital signal processing audio development platform featuring a Texas Instruments TMS320C6727 digital signal processor. i suppose its a custom board.

    The board has been working properly before this issue and i got many laboratory acoustic results with the board.
    Unfortunately i cannot try with another board. I am a PhD student at the University of Mauritius which has purchased the board , which is very costly indeed together with the emulator.

    Just a few more info about the issue. In fact, the electret mic has a positive voltage of about 2.35 Vdc at its output terminals. When this output is connected to the ADC input channel, the voltage drops to 1.75 V, even if the PADK is switched off. And the microphone no longer works i.e it does not respond to any input.

    Thanks for your help on this issue.

    Regards,

    Sajaad
  • Guru 82010 points

    In reply to Sajaad Boodoo85:

    Sajaad,

    Since the PADK is an old board and the manufacturer is not selling them anymore, do you have all of the support documentation? This would include the Technical Reference Manual and PADK schematics. These are provided by the manufacturer and not by TI, and are not the property of TI so we could not provide those even if we had them.

    When you have used the board in the past with good results, were you using an electret mic or another type of microphone? Have you used this type or this particular mic successfully in the past?

    Can you successfully connect any other type of input to the ADC input channel and have that work?

    It will be key to go back to a configuration that worked successfully in the past to confirm that configuration still works. This will verify that the board is still working well. If you cannot get the old configuration to work, then you most likely have a board problem that you will have to debug and repair yourself.

    If the old configuration does work, check the voltages at the ADC to see how it varies from what you saw with the new configuration. Make small changes, one-at-a-time to move from the old configuration to the new one and try to find the step at which things quit working.

    Regards,
    RandyP

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  • In reply to RandyP:

    Hi,

    I am getting another problem while working with the PADK. When the program is being loaded onto the microprocessor board, it gives the following message : "the controller has detected a cable break far from itself. The user must connect the cable\pod to the target". in fact, im using an interface between my pc and the PADK, which is the Blackhawk emulator USB560v2 system. I have disconnect everything and reconnect again but it gives me the same message. Its the first time, im getting this message and it was working before with the same configuration.
    Can you inform me what are the possible reasons for this?

    Regards,

    Sajaad
  • Guru 82010 points

    In reply to Sajaad Boodoo85:

    Sajaad,

    Does this mean you solved your original problem? If so, please post something about the resolution for future readers of your thread.

    I did a search on TI.com for "debugging jtag connection problems" (no quotes) and found the Wiki article Debugging JTAG Connectivity Problems legacy.

    Please read through that for some ideas and pointers to debugging your problem. The main thing I can think of is to try the Test Connection button in the View Target Configuration editor window in CCS. That usually responds back with some good information that can help point you to the problem. You may need to use some circuit testing to find if there is a signal break somewhere in your JTAG pod or cable or on the board. And make sure your emulation drivers are updated to the latest.

    Regards,
    RandyP

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  • In reply to RandyP:

    Hi Randy,

    Thanks for your reply.

    In fact, i havent been able to solve the original problem exactly. Placing a blocking capacitor at the input of the ADC does solve partly the problem.

    I'll try to find out the connection problem of the JTAG. but I would like to know if ever i would like to have the board checked, which company is offering service maintenance on the PADK.

     I have made to understand that Lyrtech is closed but i dont know which company has taken over.

    regards,

    Sajaad