Help with FFT mode

[Altera_Forum]

Hi guys, in my current setting i'm using a streaming mode FFT but thats just because it was the default setting. Another mode can help me get rid of serieus M4K-block issues. The system I have setup is like this: 

 An external ADC is hooked on my Altera DE-1 board. The serial output of this ADC is put in a 12-bit bus and than stacked in a FIFO of 2048 words. When the FIFO is full, the FFT is activated and get's the 2048 samples. When this is done the ADC is activated again.  Should I maybe use the burst, buffered burst mode of the FFT or just stick with streaming?  Thanks in advance!

[Altera_Forum]

The big problem now is that I have to figure out a scale to put the amplitude bars on the screen. now, I got 219 pixels for full hight. Problem is I got no 0 point because with absolute silence the amplitude keeps fluctuate. 

 I can easily figure out the largest number possible and set that as 100% (219 pixels). But the problem is my starting off point.

[Altera_Forum]

--- Quote Start ---  The big problem now is that I have to figure out a scale to put the amplitude bars on the screen. now, I got 219 pixels for full hight. Problem is I got no 0 point because with absolute silence the amplitude keeps fluctuate.  I can easily figure out the largest number possible and set that as 100% (219 pixels). But the problem is my starting off point.  --- Quote End ---    assuming your exponent scaling is correct(and I am not sure about the documentation so it might be correct) then I can see at least four lsbs always set at zero(out of 28 bits). Thus you can chop them off.  Moreover check the range of your exponent for your typical input and observe the MSBs. You will find some MSBs never change indicating you can remove them as well. Additionally you may control the original resolution of your fft.