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arduinoFFT
kopia lustrzana https://github.com/kosme/arduinoFFT
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- Better documentation of example.

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Enrique Condes 2014-07-19 22:43:58 -05:00
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commit 0bb257ec70
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103
Examples/FFT_01/FFT_01.ino
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@ -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
@ -39,52 +39,61 @@ double vImag[samples];
#define SCL_TIME 0x01
#define SCL_FREQUENCY 0x02
void setup(){
Serial.begin(115200);
Serial.println("Ready");
void setup()
{
Serial.begin(115200);
Serial.println("Ready");
}
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);
}
PrintVector(vReal, samples, SCL_TIME);
FFT.Windowing(vReal, samples, FFT_WIN_TYP_HAMMING, FFT_FORWARD); /* Weigh data */
PrintVector(vReal, samples, SCL_TIME);
FFT.Compute(vReal, vImag, samples, FFT_FORWARD); /* Compute FFT */
PrintVector(vReal, samples, SCL_INDEX);
PrintVector(vImag, samples, SCL_INDEX);
FFT.ComplexToMagnitude(vReal, vImag, samples); /* Compute magnitudes */
PrintVector(vReal, (samples >> 1), SCL_FREQUENCY);
double x = FFT.MajorPeak(vReal, samples, samplingFrequency);
Serial.println(x, 6);
while(1); /* Run Once */
// delay(2000); /* Repeat after delay */
/* Build raw data */
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);
double x = FFT.MajorPeak(vReal, samples, samplingFrequency);
Serial.println(x, 6);
while(1); /* Run Once */
// delay(2000); /* Repeat after delay */
}
void PrintVector(double *vData, uint8_t bufferSize, uint8_t scaleType)
{
for (uint16_t i = 0; i < bufferSize; i++) {
double abscissa;
/* Print abscissa value */
switch (scaleType) {
case SCL_INDEX:
abscissa = (i * 1.0);
break;
case SCL_TIME:
abscissa = ((i * 1.0) / samplingFrequency);
break;
case SCL_FREQUENCY:
abscissa = ((i * 1.0 * samplingFrequency) / samples);
break;
}
Serial.print(abscissa, 6);
Serial.print(" ");
Serial.print(vData[i], 4);
Serial.println();
}
Serial.println();
}
{
for (uint16_t i = 0; i < bufferSize; i++)
{
double abscissa;
/* Print abscissa value */
switch (scaleType)
{
case SCL_INDEX:
abscissa = (i * 1.0);
break;
case SCL_TIME:
abscissa = ((i * 1.0) / samplingFrequency);
break;
case SCL_FREQUENCY:
abscissa = ((i * 1.0 * samplingFrequency) / samples);
break;
}
Serial.print(abscissa, 6);
Serial.print(" ");
Serial.print(vData[i], 4);
Serial.println();
}
Serial.println();
}