Hello everyone, I'm currently work on an audio project where a microphone detects a sound in HZ then plays the same sound through a speaker repeatedly, but I can not seem to get my code right. Any help is appreciated thanks. 
Heres the code...
Note: The arduinoFFT.h library needs to be added to the Arduino IDE before compiling and uploading this script/sketch to an Arduino.
/*
#include "arduinoFFT.h"
#define SAMPLES 128 //SAMPLES-pt FFT. Must be a base 2 number. Max 128 for Arduino Uno.
#define SAMPLING_FREQUENCY 2048 //Ts = Based on Nyquist, must be 2 times the highest expected frequency.
arduinoFFT FFT = arduinoFFT();
unsigned int samplingPeriod;
unsigned long microSeconds;
double vReal[SAMPLES]; //create vector of size SAMPLES to hold real values
double vImag[SAMPLES]; //create vector of size SAMPLES to hold imaginary values
void setup()
{
Serial.begin(115200); //Baud rate for the Serial Monitor
samplingPeriod = round(1000000*(1.0/SAMPLING_FREQUENCY)); //Period in microseconds
pinMode(9, OUTPUT);
}
void loop()
{
/Sample SAMPLES times/
for(int i=0; i<SAMPLES; i++)
{
microSeconds = micros(); //Returns the number of microseconds since the Arduino board began running the current script.
vReal[i] = analogRead(0); //Reads the value from analog pin 0 (A0), quantize it and save it as a real term.
vImag[i] = 0; //Makes imaginary term 0 always
/*remaining wait time between samples if necessary*/
while(micros() < (microSeconds + samplingPeriod))
{
//do nothing
}
}
/*Perform FFT on samples*/
FFT.Windowing(vReal, SAMPLES, FFT_WIN_TYP_HAMMING, FFT_FORWARD);
FFT.Compute(vReal, vImag, SAMPLES, FFT_FORWARD);
FFT.ComplexToMagnitude(vReal, vImag, SAMPLES);
/*Find peak frequency and print peak*/
double peak = FFT.MajorPeak(vReal, SAMPLES, SAMPLING_FREQUENCY);
Serial.println(peak); //Print out the most dominant frequency.
tone(peak);
reset
}
