Can the arduino detect frequencies?

I want to make a spectrum analyser and I want to use a micro controller, but I don't know how.
I want to know if the arduino (any one) can split up the different frequencies and output them, so I can use it as an input to an LED driver (LM3915).
This will allow the LEDs to be at full brightness and respond to the output of the arduino, if the frequency filter is possible.
If not, I will use a series of bandpass filters instead.

I want to make an 8 band spectrum analyser. I just thought that using an arduino would be cheaper.

Thanks.

The schematic I will be using:
http://stavebnice.postreh.com/picture/PT041_schem_v.gif

iceng4 years ago
Study up on FFT ( Fast Fourier Transforms ) which can mathematically
perform audio frequency differentiation analysis suitable to LED driving
in small micros.

Then there are probably software sites that have free code...

A
iceng iceng4 years ago
BTW the circuit you want to use is an analog differentiation all by itself ! ?

No need for a micro there.

Like Knex bad fit.
He's given up on that by the look of it. All his recent questions have been about a spectrum analyser.
Its very complicated, and there is no way you'll understand how it works, but the FFT will do very nicely. Google FFT and Arduino, and you can find code that Just Works.

The display won't need LM3915s, you'd be better attaching a MAX7221 chip to the arduino. I suggest you do a nice simple 8 level x 8 channel display, one 7221 worth of LEDS