Help to build an Audio spectrum analyzer

[ro_ok_bo]

I’d like to build an Audio spectrum analyzer with a PIC and a little/medium graphic Display.

I don’t like the PC solution by a internal sound card

Anybody can help me please?

 

[E-design]

To sample the spectrum from say 20-20kHz in real time will need a lot of processing power unless you split your sampling into specific bands (like on a graphic equalizer). Most high end analyzers use FFT routines and/or DSP processing for the task

 

[cesare]

Yes, it is true, modern audio specrum analyzer uses DSP to extract the spectral component of the audio signal.

However both Analog Devices and Texas Instruments make available very low cost ev-board of their device and the application you want to build is very common and so I think you can easily find the algorithm you need (substantially an FFT)

In the zip file attached you will find several audio algorithms for ADSP2181 with the m code for simulate them on matlab.

 

[pva]

Hi,
my opinion is that with PIC16 is impossible to do more than 16 - point FFT in real time,I try to build DTMF decoder with PIC16F876 use internal ADC and failed.

 

[Zedman]

I think on a smaller display (to be visible from longer distances (from your bed for ex.)) i think it's enough to have 16 columns. And the display can
be a 20x4 char LCD. (you should design 1-8 pixel
high blocks and you have 20 32 pixel high cols for
drawing nice bars

teorethically...

Zed