kopia lustrzana https://github.com/kosme/arduinoFFT
84 wiersze
2.7 KiB
C++
84 wiersze
2.7 KiB
C++
/*
|
|
|
|
Example of use of the FFT libray to compute FFT for a signal sampled through the ADC.
|
|
Copyright (C) 2017 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
|
|
the Free Software Foundation, either version 3 of the License, or
|
|
(at your option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
GNU General Public License for more details.
|
|
|
|
You should have received a copy of the GNU General Public License
|
|
along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
*/
|
|
|
|
#include "arduinoFFT.h"
|
|
|
|
arduinoFFT FFT = arduinoFFT(); /* Create FFT object */
|
|
/*
|
|
These values can be changed in order to evaluate the functions
|
|
*/
|
|
#define CHANNEL A0
|
|
const uint16_t samples = 64; //This value MUST ALWAYS be a power of 2
|
|
const double samplingFrequency = 200;
|
|
|
|
unsigned int delayTime = 0;
|
|
|
|
/*
|
|
These are the input and output vectors
|
|
Input vectors receive computed results from FFT
|
|
*/
|
|
double vReal[samples];
|
|
double vImag[samples];
|
|
|
|
#define SCL_INDEX 0x00
|
|
#define SCL_TIME 0x01
|
|
#define SCL_FREQUENCY 0x02
|
|
|
|
void setup()
|
|
{
|
|
if(samplingFrequency<=1000)
|
|
delayTime = 1000/samplingFrequency;
|
|
else
|
|
delayTime = 1000000/samplingFrequency;
|
|
Serial.begin(115200);
|
|
Serial.println("Ready");
|
|
}
|
|
|
|
void loop()
|
|
{
|
|
for(uint16_t i =0;i<samples;i++)
|
|
{
|
|
vReal[i] = double(analogRead(CHANNEL));
|
|
vImag[i] = 0.0; //Imaginary part must be zeroed in case of looping to avoid wrong calculations and overflows
|
|
if(samplingFrequency<=1000)
|
|
delay(delayTime);
|
|
else
|
|
delayMicroseconds(delayTime);
|
|
}
|
|
/* Print the results of the sampling according to time */
|
|
Serial.println("Data:");
|
|
FFT.PrintSignal(vReal, samples, samplingFrequency);
|
|
FFT.Windowing(vReal, samples, FFT_WIN_TYP_HAMMING, FFT_FORWARD); /* Weigh data */
|
|
Serial.println("Weighed data:");
|
|
FFT.PrintSignal(vReal, samples, samplingFrequency);
|
|
FFT.Compute(vReal, vImag, samples, FFT_FORWARD); /* Compute FFT */
|
|
Serial.println("Computed Real values:");
|
|
FFT.PrintVector(vReal, samples, samplingFrequency);
|
|
Serial.println("Computed Imaginary values:");
|
|
FFT.PrintVector(vImag, samples, samplingFrequency);
|
|
FFT.ComplexToMagnitude(vReal, vImag, samples); /* Compute magnitudes */
|
|
Serial.println("Computed magnitudes:");
|
|
FFT.PrintSpectrum(vReal, samples, samplingFrequency);
|
|
double x = FFT.MajorPeak(vReal, samples, samplingFrequency);
|
|
Serial.println(x, 6);
|
|
while(1); /* Run Once */
|
|
// delay(2000); /* Repeat after delay */
|
|
}
|