ATmega8 Spectrum Analyzer

[Manekinen] built a very responsive spectrum analyzer. The components at the party are what you’d expect, an ATmega8 does the hard work interpreting data from the LM324 op-amp. This build stands out because it is fast and configurable. In fact, the explanation of the calibration process is where this project shines.

Instead of using water, an HD44780 module displays the spectrum data. The device currently supports several different character displays including 16×2, 20×2, 24×2, and 20×2. We’ve embedded a video of a 20×4 VFD in action after the break. As the video progresses, watch for the Polish words that pop up. This corresponds to the brightness and sensitivity being adjusted with the 5-button keyboard.


17 thoughts on “ATmega8 Spectrum Analyzer

  1. i was disappointed in that, it is just some sort of wiz-bang display to put on a head-unit. I was hoping for a real audio spectrum analyzer that has dbu vs freq, adjustable BW, etc for optimizing amplifiers.

  2. why spectrum analyzers are so expensive, even really old ones. VNAs drop in price , ociloscopes become almost mass product, why its not true with spectrum analyzers especially when digital math forier transform become cheap and avable

  3. @Natalie
    All you guys need to do is change the file extension on file you downloaded from .tmp to .rar

    so instead of FP3YICPG3KY0NSJ.tmp
    it should say FP3YICPG3KY0NSJ.rar

    If you can’t see the file extension, go to ‘Tools’ –> ‘Folder options’ –> UNcheck “hide file extensions for known file types”


  4. Sorry for the off topic, but dos anybody know what song that is playing in the very beginning? I tried to tag it @ several parts with shazam on my phone, but it couldn’t find a definitive match. MUCH APPRECIATED!

  5. @carl
    .zip files as we know them are just containers, they support nearly any compression scheme. I believe that is the same for nearly all proprietary extensions (.7z, .rar, .zip).

    unix got it right:

  6. @therian: A lot of the digital scopes do have an FFT function. I’ve got a relatively inexpensive one and it does it on either channel. I also have one of the USB-based ‘scopes from Syscomp and it has a VNA mode where it syncs the function generator output with the A/B inputs and gives you a transfer function. I use it a lot for filter verification. Pretty awesome, really, for a $189 tool.

  7. @Natalie:
    RARs have nice compression, error recovery, can be easily split and joined, and lend themselves well to embedding in pictures and such, making them good for piracy and and software which needs to be mostly pristine. This led to its use by pirates and softmodders. Since many people have the software anyway, a lot of people use it for more.

    For windows: WinRAR ( [Yea it’s commercial, but the free trial never expires])
    For linux: RAR and UNRAR command-line ( [Some linux apps support .rars from the start, but many need the official cmd-line apps to work])
    For OSX: UnrarX or Stuffit Expander ( [not much to say, only expands] [Wonderful software, but needs a name and email])

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