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OpenAudio_ArduinoLibrary/examples/TestFFT1024/TestFFT1024.ino

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//
// TestFFT1024.ino Bob Larkin W7PUA
// Started from PJRC Teensy Examples/Audio/Analysis/FFT
//
// Compute a 1024 point Fast Fourier Transform (spectrum analysis)
// on audio connected to the Left Line-In pin. By changing code,
// a synthetic sine wave can be input instead.
//
// The power output from 512 frequency analysis bins are printed to
// the Arduino Serial Monitor. The format is selectable.
// Output power averaging is an option
//
// T4.0: Uses 7.8% processor and 9 F32 memory blocks, both max.
//
// This example code is in the public domain.
#include <Audio.h>
#include "OpenAudio_ArduinoLibrary.h"
// Create the Audio components. These should be created in the
// order data flows, inputs/sources -> processing -> outputs
//
// AudioInputI2S_F32 audioInput; // audio shield: mic or line-in
AudioSynthSineCosine_F32 sinewave;
AudioAnalyzeFFT1024_F32 myFFT;
AudioOutputI2S_F32 audioOutput; // audio shield: headphones & line-out NU
// Connect either the live input or synthesized sine wave
// AudioConnection_F32 patchCord1(audioInput, 0, myFFT, 0);
AudioConnection_F32 patchCord1(sinewave, 0, myFFT, 0);
AudioControlSGTL5000 audioShield;
float saveDat[512];
void setup() {
Serial.begin(300); // Any speed works
delay(1000);
AudioMemory_F32(50);
// Enable the audio shield and set the output volume.
audioShield.enable();
audioShield.inputSelect(AUDIO_INPUT_LINEIN);
// Create a synthetic sine wave, for testing
// To use this, edit the connections above
// sinewave.frequency(1033.99f); // Bin 24 T3.x
// sinewave.frequency(1033.59375f); // Bin 24 T4.x at 44100
// sinewave.frequency(1055.0f); // Bin 24.5, demonstrates windowing
// Or some random frequency:
sinewave.frequency(1234.5f);
sinewave.amplitude(1.0f);
// Set windowing function
// myFFT.windowFunction(AudioWindowNone);
// myFFT.windowFunction(AudioWindowHanning1024); // default
// The next Kaiser window needs a dB peak sidelobe number
// myFFT.windowFunction(AudioWindowKaiser1024, 70.0f);
myFFT.windowFunction(AudioWindowBlackmanHarris1024);
// To print the window function:
// float* pw=myFFT.getWindow();
// for(int jj=0; jj<1024; jj++)
// Serial.println(*pw++, 6);
myFFT.setNAverage(1);
myFFT.setOutputType(FFT_DBFS); // FFT_RMS or FFT_POWER or FFT_DBFS
Serial.println("1024 point real FFT output in dB relative to full scale sine wave");
}
void loop() {
static uint32_t nTimes = 0;
if ( myFFT.available() ) {
// each time new FFT data is available
// print it all to the Arduino Serial Monitor
float* pin = myFFT.getData();
for (int kk=0; kk<512; kk++)
saveDat[kk]= *(pin + kk);
if(++nTimes>4 && nTimes<6) {
for (int i=0; i<512; i++) {
Serial.print(i);
Serial.print(", ");
Serial.println(saveDat[i], 8);
}
Serial.println();
Serial.print("CPU: Max Percent Usage: ");
Serial.println(AudioProcessorUsageMax());
Serial.print(" Max Float 32 Memory: ");
Serial.println(AudioMemoryUsageMax_F32());
}
}
}