Using FFT to analyze a sine wave

[bhav]

Hello, I am a total beginner in FPGAs. I am to analyse an input wave using A/D and then take FFT of certain number of samples. Input wave is of 50 Hz and sampling frequency of A/D is 1.6Khz. However that is only math! I am not able to check whether my code works or not. Right now I am done only with the A/D part thanks to zybdo xadc demo on this website! Can anyone help me by telling whether my A/C is wor king fine?  Also please guide me as how I could proceed. Thank you.

project_6.xpr

[jpeyron]

Hi @bhav,

I need more that just the xpr file to launch your project. I would look at our working hdl xadc project for the zybo here. Here is forum thread that discusses using the zybo xadc in the ps. The forum thread has a block design and sdk code of a working project.

thank you,

Jon

zybo_xadc_test.c

[D@n]

@bhav,

I recently put a demonstration project together for just this purpose on my github page.  You can find it here.  Although it's entirely a simulated project, you should find some useful pieces within it.  Key details include:

1. 1Msps A/D, based upon Digilent's PMod MIC3--a MEM's based PMod.  Of course, since this is entirely a simulated project, no PMod MIC3 is actually required.  The project just demonstrates how Verilog code can interact with the A/D in a simulated fashion.  In this case, there's a MICNCO C++ file that simulates the Pmod.
2. 1ksps complex FFT.  (My core generator doesn't yet build real FFT's)
3. DMA data write to memory.  This is all based upon a wishbone bus--much simpler to work with than AXI.
4. Video read from memory onto a simulated VGA 800x600 screen.  (GTK based)  The pixel clock is a 40MHz clock, the system bus/memory clock runs at 100MHz.
5. The video slides from the right to the left as new data comes in.

Feel free to take a look, and then ask yourself how you would go about simulating your task in order to know that your code works in the first place.

Dan