Arduino.ru

#include "arduinoFFT.h"
#include <math.h>
#define SAMPLES 128             //Must be a power of 2
#define SAMPLING_FREQUENCY 1000 //Hz, must be less than 10000 due to ADC
////////////////////
int i;
int A;
int amplitude;
const uint16_t samples = 64; //This value MUST ALWAYS be a power of 2
const double signalFrequency = 1000;
const double samplingFrequency = 5000;
//const uint8_t amplitude = 100;
///////////////////
arduinoFFT FFT = arduinoFFT();

unsigned int sampling_period_us;
unsigned long microseconds;

double vReal[SAMPLES];
double vImag[SAMPLES];

void setup() {
  Serial.begin(115200);

  sampling_period_us = round(1000000 * (1.0 / SAMPLING_FREQUENCY));
}

void loop() {

  /*SAMPLING*/
  for (int i = 0; i < SAMPLES; i++)
    // for (uint16_t i = 0; i < SAMPLES; i++)
  {
    microseconds = micros();    //Overflows after around 70 minutes!

    vReal[i] = analogRead(PA7);
    vImag[i] = 0;

    while (micros() < (microseconds + sampling_period_us)) {
    }

    ////////////////////////
    float A = atan( vImag[i] / vReal[i] );
    double cycles = (((samples - 1) * signalFrequency) / samplingFrequency);
    for (uint16_t i = 0; i < SAMPLES; i++)
    {
      // const uint8_t amplitude = analogRead(PA7);
      uint8_t amplitude[i] = analogRead(PA7);
      amplitude[i] = 0
                     // amplitude  = analogRead(PA7);

                     vReal[i] = int8_t((amplitude * (sin((i * (twoPi * cycles)) / samples))) / 2.0);
      vImag[i] = int8_t((amplitude * (cos((i * (twoPi * cycles)) / samples))) / 2.0);
    }
    ////////////////////////

  }

  /*FFT*/
  FFT.Windowing(vReal, SAMPLES, FFT_WIN_TYP_HAMMING, FFT_FORWARD);
  FFT.Compute(vReal, vImag, SAMPLES, FFT_FORWARD);
  FFT.ComplexToMagnitude(vReal, vImag, SAMPLES);
  double peak = FFT.MajorPeak(vReal, SAMPLES, SAMPLING_FREQUENCY);

  /*PRINT RESULTS*/
  //Serial.println(peak);     //Print out what frequency is the most dominant.

  for (int i = 0; i < (SAMPLES / 2); i++)
    // for (uint16_t i = 0; i < SAMPLES/2; i++)
  {
    /*View all these three lines in serial terminal to see which frequencies has which amplitudes*/

    //Serial.print((i * 1.0 * SAMPLING_FREQUENCY) / SAMPLES, 1);
    //Serial.print(" ");
    // Serial.println(vReal[i], 1);    //View only this line in serial plotter to visualize the bins
    Serial.println(A);
  }
}