The following is the link to a well described, brief FFT algorithm that can be computed using an Arduino board. The website's called "Arduinoos" and its definitely worth checking out ( especially for FFT ).
If you have gone through the above link, you would have noticed a comment that reads "Build raw data". I couldn't figure out the actual meaning of this part.
Also, my project idea involves giving an analog signal as input to the ADC of Arduino. How do I achieve that within the scope of this code?
for (uint8_t i = 0; i < samples; i++)
{
vReal[i] = uint8_t((signalIntensity * (sin((i * (6.2831 * cycles)) / samples) + 1.0)) / 2.0);
}
is filling the array vReal with test data, in this case I think its a sine wave.
You could fill vReal with data from the ADC instead, there are plenty of examples of doing FFT on audio, to display those bar graph type spectrum analysis displays
Okay. I was thinking on similar lines. However, the bigger question is this: If you look up at the code, you will find that the signal frequency and the sample frequency are pre-defined / constant. In the case wherein I utilize an analog signal generated through a frequency generator at the ADC pin of the Arduino board, what effect will this have on the characteristics?
Is this the right way to go about this idea?
Also, could you please alaborate on how exactly I can fill the above mentioned part with data from ADC. The exact methodolgy will be quite useful !
You asked about filling the FFT input buffer using the ADC, not about printing.
That example was not intended to print the values to the serial monitor, rather it sends them to another application for graphing. If you want to print the results, use a loop, and use serial.print rather than serial.write to output the result.