- Better documentation of example.

Examples/FFT_01/FFT_01.ino

@@ -1,7 +1,7 @@
 /*
 
 	Example of use of the FFT libray
-	Copyright (C) 2011 Didier Longueville
+        Copyright (C) 2014 Enrique Condes
 
 	This program is free software: you can redistribute it and/or modify
 	it under the terms of the GNU General Public License as published by
@@ -18,16 +18,16 @@
 	
 */
 
-#include "PlainFFT.h"
+#include "arduinoFFT.h"
 
-PlainFFT FFT = PlainFFT(); /* Create FFT object */
+arduinoFFT FFT = arduinoFFT(); /* Create FFT object */
 /* 
 These values can be changed in order to evaluate the functions 
 */
-const uint16_t samples = 64;
+const uint16_t samples = 64; //This value MUST ALWAYS be a power of 2
 double signalFrequency = 1000;
 double samplingFrequency = 5000;
-uint8_t signalIntensity = 100;
+uint8_t amplitude = 100;
 /* 
 These are the input and output vectors 
 Input vectors receive computed results from FFT
@@ -39,7 +39,8 @@ double vImag[samples];
 #define SCL_TIME 0x01
 #define SCL_FREQUENCY 0x02
 
-void setup(){
+void setup()
+{
   Serial.begin(115200);
   Serial.println("Ready");
 }
@@ -47,15 +48,21 @@ void setup(){
 void loop() 
 {
   /* Build raw data */
-	double cycles = (((samples-1) * signalFrequency) / samplingFrequency);
-	for (uint8_t i = 0; i < samples; i++) {
-		vReal[i] = uint8_t((signalIntensity * (sin((i * (6.2831 * cycles)) / samples) + 1.0)) / 2.0);
+  double cycles = (((samples-1) * signalFrequency) / samplingFrequency); //Number of signal cycles that the sampling will read
+  for (uint8_t i = 0; i < samples; i++) 
+  {
+    vReal[i] = uint8_t((amplitude * (sin((i * (6.2831 * cycles)) / samples))) / 2.0);/* Build data with positive and negative values*/
+    //vReal[i] = uint8_t((amplitude * (sin((i * (6.2831 * cycles)) / samples) + 1.0)) / 2.0);/* Build data displaced on the Y axis to include only positive values*/
   }
+  Serial.println("Data:");
   PrintVector(vReal, samples, SCL_TIME);
   FFT.Windowing(vReal, samples, FFT_WIN_TYP_HAMMING, FFT_FORWARD);	/* Weigh data */
+  Serial.println("Weighed data:");
   PrintVector(vReal, samples, SCL_TIME);
   FFT.Compute(vReal, vImag, samples, FFT_FORWARD); /* Compute FFT */
+  Serial.println("Computed Real values:");
   PrintVector(vReal, samples, SCL_INDEX);
+  Serial.println("Computed Imaginary values:");
   PrintVector(vImag, samples, SCL_INDEX);
   FFT.ComplexToMagnitude(vReal, vImag, samples); /* Compute magnitudes */
   PrintVector(vReal, (samples >> 1), SCL_FREQUENCY);	
@@ -67,10 +74,12 @@ void loop()
 
 void PrintVector(double *vData, uint8_t bufferSize, uint8_t scaleType) 
 {
-	for (uint16_t i = 0; i < bufferSize; i++) {
+  for (uint16_t i = 0; i < bufferSize; i++) 
+  {
     double abscissa;
     /* Print abscissa value */
-		switch (scaleType) {
+    switch (scaleType) 
+    {
       case SCL_INDEX:
         abscissa = (i * 1.0);
 	break;