• State Resolved
  • Locked Locked
  • Replies 9 replies
  • Answers 1 answer
  • Subscribers 82 subscribers
  • Views 611 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Compiler/TMS320F28379D: 2837x_RFFT_ADC

nolan
Intellectual 590 points

Part Number: TMS320F28379D
Other Parts Discussed in Thread: C2000WARE

Tool/software: TI C/C++ Compiler

Hi,

I  am new to TMS320F28379D , these are a few doubts i have ...

1.what is the input and output buffer of this program?

2.How to make a connections to this program ,am not getting this part ,can you please explain.. this was given in the program 

" EPWM1 and 2 are setup such that EPWM2 outputs a square wave at a  frequency 10 times slower than EPWM1; EPWM1 serves as the sample clock to the ADC which will sample EPWM2A (pin 53) through channel A0 (pin 09) and then run the FFT.  "

3.can we give input signal directly from signal generator instead of Epwm?

4.where and how FFT is implemented in this program?

5.How to add  RUN option in our ccs8, as i want to check  cycles of our program. 

Below i have attached image

Regards,

Ashwin

  • 0
    Intellectual 590 points
    Hi,
    Can i get a reply please ,asap.
  • 0 in reply to nolan
    TI__Mastermind 27145 points
    Hi Ashwin,

    I will review your questions and get back to you in a day.

    Thanks,
    Sira
  • 0 in reply to nolan
    TI__Mastermind 27145 points
    Ashwin,

    1.what is the input and output buffer of this program?
    Answer: Please read section 5.12 of user guide, located at C:\ti\c2000\C2000Ware_1_00_06_00\libraries\dsp\FPU\c28\docs

    2.How to make a connections to this program ,am not getting this part ,can you please explain.. this was given in the program

    " EPWM1 and 2 are setup such that EPWM2 outputs a square wave at a frequency 10 times slower than EPWM1; EPWM1 serves as the sample clock to the ADC which will sample EPWM2A (pin 53) through channel A0 (pin 09) and then run the FFT. "

    Answer: Are you using the ControlCARD Docking Station? These are Pins on the docking station.

    3.can we give input signal directly from signal generator instead of Epwm?
    Answer: Absolutely. Just connect the signal generator output to Pin 09.

    4.where and how FFT is implemented in this program?
    Answer:: This project includes a library c28x_fpu_dsp_library.lib that implements the FFT in assembly language. The project that builds this library is located at C:\ti\c2000\C2000Ware_1_00_06_00\libraries\dsp\FPU\c28\ccs

    5.How to add RUN option in our ccs8, as i want to check cycles of our program.
    Answer: Are you saying the Run option is missing? I see it in my view of CCSv8.2.

    Thanks,
    Sira
  • 0 in reply to Sira Rao80
    Intellectual 590 points

    Hi,

    The FFT output is not what i expected . I have plotted the graph of RFFTmagBuff to check the FFT of the given input .

    I have attached the screenshot  of the both input and fft .

    Input is  square wave of 1kHz of 1Vpp with offset of 0.5v and input has been seen  in RFFTin1Buff

    Regards,

    Ashwin

  • 0 in reply to nolan
    TI__Mastermind 27145 points
    The fact that you are seeing the input signal correctly in CCS is a good sign.

    You can try the following:

    1. Switch to a pure sinusoidal wave.
    2. Check the properties of your single time graph - ensure you have the right Resolution (16-bit), display size (equal to size of FFT), vector to display (RFFTmagBuff). Also for the type of plot, be sure to select Single time (which it seems you have done) and not FFT magnitude, since the RFFTmagBuff buffer already contains FFT magnitude values.
    3. Try right clicking on the Figure and checking OFF and ON the AutoScale option.

    If none of these help, take a step back, and change USE_TEST_INPUT to 1 in main.c, include signal.asm in the build, and build and run the project. See if it Passes ("pass", "fail" variables). This will let you know if the FFT library is running correctly in your setup.

    Thanks,
    Sira
  • 0 in reply to Sira Rao80
    Intellectual 590 points
    thanks for the quick response , I will implement the changes which you have told and check the graph.


    Regards,
    Ashwin
  • 0 in reply to nolan
    TI__Mastermind 27145 points
    Hi Ashwin – I haven’t heard back from you, were you able to resolve your issue?

    Thanks,
    Sira
  • 0 in reply to Sira Rao80
    Intellectual 590 points
    Hi Sira ,

    I tired the above changes as mentioned by you but still the fft output seems to be the same irrespective of the shape of my wave .
    Sorry for the delayed response due the tight schedule .


    Regards,
    Ashwin
  • 0 in reply to nolan
    TI__Mastermind 27145 points
    Ashwin,

    I didn't see a response on this comment of mine
    "If none of these help, take a step back, and change USE_TEST_INPUT to 1 in main.c, include signal.asm in the build, and build and run the project. See if it Passes ("pass", "fail" variables). This will let you know if the FFT library is running correctly in your setup"

    Did you try this? What was the result?

    Thanks,
    Sira