How to display DSP results on a PC?

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Circuit_seller

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How to Display Results?

Hi

I have designed a spectrum analyzer with a DSP.
The DSP performs FFT in 1024, 512, 256, ... number of points.
and the frequency span also can be changed. So number of results depending of the span and resolution can change.
I send the result to PC to display.
Because of limited resolution of display(i.e. 400 pixels) i should do a resampling on the results and then send them to PC.
i am looking for a code to do this resampling with arbitrary resampling ratio.

Thanks in advance.
 

Re: How to Display Results?

Hi Circuit_seller,
What DSP chip are you using?

How did you input the math formula into the assembly? Did you do your programming in C first then convert into assembly?
 

Re: How to Display Results?

Hi

The DSP is F2811 and the FFT code is in assembly, but the main code is in C.

Regards
 

Re: How to Display Results?

Hi

Still looking for any answer ...
 

Re: How to Display Results?

Have you use matlab?
If you does, you can trace the imsize function provided by image processing toolbox.


Regards,
Jarod
 

How to Display Results?

I take a different approach. When I plot stuff on a PC display, I use OpenGL with anti-aliasing enabled. That automatically gives nice smooth lines and curves at any scale. And on a modern graphics card it's really fast.
 

Re: How to Display Results?

Hi echo47

what is openGL? can you explain more about it?
I am using delphi 2.0 to display results.

Regards
 

How to Display Results?

http://www.opengl.org/about/overview.html

Try a Google search for delphi opengl and you'll find tons of sites with examples and tutorials. OpenGL is used mostly for 3D, but it does 2D too. OpenGL may seem like overkill, since all you need are anti-aliased lines, but oh well, it's built into Windows. I assume your program runs under Windows.

I've never done OpenGL in Delphi, but I grabbed a few files (firststeps.zip, dot.zip, cglib.zip) from this site, fiddled around with DCC32 (Delphi 7) for a few minutes, and successfully compiled the OpenGL example.
**broken link removed**

I think DirectX is equally suitable, but I've never used it.

Here is a screen-grab of my OpenGL program displaying a 1024 point FFT in a too-small window. The green line segments pile up just like you'd want them to.
 
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