Colecting and processing infomation from an AUX.

Hello.

So I am working on a little project using my Arduino Lilypad. One part of this project involves taking in audio from an Aux cable and processing the sounds volume and frequincey/pitch in to verables kinda like an Audio spectrum analyzer(some people call an graphic equalizer) would use. The problem is I have no Idear how to turn the sound from the AUX into the verables to use for the rest of the project.

Is there some tutorials or libraries out there that will allow me to do this? there should be something.
When I try to do my own googling I only find things like this http://www.instructables.com/id/Arduino-Processing-Audio-Spectrum-Analyzer/
However that only explains the visual part witch I don't even need. I need the gathering the audio information witch I can not seem to find out how to do.

Use a MSGEQ7 chip, that will split the sound up into seven frequency bands and read it in through one analogue input.

from an AUX.

That would be a [u]line level[/u] signal.

like an Audio spectrum analyzer(some people call an graphic equalizer) would use.

They are different things... An equalizer alters the frequency balance of the sound. An analog equalizer doesn't "know" anything about the signal, it just processes/filters whatever comes through. A spectrum analyzer displays the frequency content. (The MSGEQ7 is mis-named as an equalizer chip... That's not what it is.)

However that only explains the visual part witch I don't even need. I need the gathering the audio information witch I can not seem to find out how to do.

What are you going to do with the data? You can't "gather" and store much audio information with the Arduino because of it's limited memory.

The problem is I have no Idear how to turn the sound from the AUX into the verables to use for the rest of the project.

As Mike says, the [u]MSGEQ7[/u] is the easiest way to go if you only need 7 bands. The chip takes the audio signal and gives you 7 (multiplexed) varying DC outputs that can be easily read by the Arduino. It's about 100 times more complicated to do the frequency analysis in software.

The problem is I have no Idear how to turn the sound from the AUX into the verables to use for the rest of the project.

Assuming you're not using the MSGEQ7 -

First, the Arduino can't read the negative half of the AC audio signal. The Arduino can potentially be be damaged by negative signals and if the Arduino survives the signal will be "damaged" (distorted). You have to [u]bias the Arduino's input[/u] so it doesn't go negative. (You can subtract-out the bias in software.)

Then, you "sample" the audio at a fixed-known sample rate. (CDs have a sample rate of 44.1kHz, but the Arduino can't sample quite that fast.) The Audacity website has a little [u]tutorial[/u] about how audio is sampled. Once you've got digitized audio, you use [u]FFT[/u] (or DFT or FHT) to extract the frequency information.

FFT is digital signal processing (DSP). It's advanced math and advanced programming. There are libraries so you don't have to write the code yourself, but you need to understand the basics and how to use the library.

Ok so assuming I go down the MSGEQ7 route.

Is there any tutorials or other forms of documentation explaining how to use it with Arduino's.
I took a look at the datasheet there And i understand that VDD is voltage in and VSS is voltage out. (which i can connect to my lipo 3.7v battery) however everything else is just guess work.

is OUT the signle sent to the Arduino?
is STROBE the pin that desides witch band is going through the out?
is IN well I am going to say that IN is the input from the AUX and GND is the GND from the AUX
and I have no clue what reset or the clock oscillator pin are or what they are used for.

and if that is true How do I read the OUT signle on the ardunio?
Do i need to send a signle from the Ardunio to the STROBE to chose what band is sent from the OUT to the Ardunio?
How do I tell the STROBE what BAND to use? is it an PWM value?
Or have i got this all wrong?

Try this tutorial.
http://forum.arduino.cc/index.php?topic=146044.0