Frequencies.ino

/*
    Frequencies.ino
    By Shea Ivey

    Reads I2S microphone data into samples[], processes them into frequency buckets and then outputs it to the serial plotter for viewing.
    Try wistling differrent tones to see which frequency buckets they fall into.

    TIP: uncomment the audioInfo.autoLevel() to see how the loud and quiet noises are handled.
*/

#include <AudioInI2S.h>

#define SAMPLE_SIZE 1024  // Buffer size of read samples
#define SAMPLE_RATE 44100 // Audio Sample Rate

/* Required defines for audio analysis */
#define BAND_SIZE 8 // powers of 2 up to 64, defaults to 8

#include <AudioAnalysis.h>
AudioAnalysis audioInfo;

// ESP32 S2 Mini
// #define MIC_BCK_PIN 4             // Clock pin from the mic.
// #define MIC_WS_PIN 39             // WS pin from the mic.
// #define MIC_DATA_PIN 5            // SD pin data from the mic.
// #define MIC_CHANNEL_SELECT_PIN 40 // Left/Right pin to select the channel output from the mic.

// ESP32 TTGO T-Display
#define MIC_BCK_PIN 32            // Clock pin from the mic.
#define MIC_WS_PIN 25             // WS pin from the mic.
#define MIC_DATA_PIN 33           // SD pin data from the mic.
#define MIC_CHANNEL_SELECT_PIN 27 // Left/Right pin to select the channel output from the mic.

AudioInI2S mic(MIC_BCK_PIN, MIC_WS_PIN, MIC_DATA_PIN, MIC_CHANNEL_SELECT_PIN); // defaults to RIGHT channel.

int32_t samples[SAMPLE_SIZE]; // I2S sample data is stored here

void setup()
{
  Serial.begin(115200);
  mic.begin(SAMPLE_SIZE, SAMPLE_RATE); // Starts the I2S DMA port.

  // audio analysis setup
  audioInfo.setNoiseFloor(10);       // sets the noise floor
  audioInfo.normalize(true, 0, 255); // normalize all values to range provided.

  // audioInfo.autoLevel(AudioAnalysis::ACCELERATE_FALLOFF, 1); // uncomment this line to set auto level falloff rate
  audioInfo.bandPeakFalloff(AudioAnalysis::EXPONENTIAL_FALLOFF, 0.05); // set the band peak fall off rate
  audioInfo.vuPeakFalloff(AudioAnalysis::EXPONENTIAL_FALLOFF, 0.05);    // set the volume unit peak fall off rate
}

void loop()
{
  mic.read(samples); // Stores the current I2S port buffer into samples.
  audioInfo.computeFFT(samples, SAMPLE_SIZE, SAMPLE_RATE);
  audioInfo.computeFrequencies(BAND_SIZE);

  float *bands = audioInfo.getBands();
  float *peaks = audioInfo.getPeaks();
  float vuMeter = audioInfo.getVolumeUnit();
  float vuMeterPeak = audioInfo.getVolumeUnitPeak();

  // Send data to serial plotter
  for (int i = 0; i < BAND_SIZE; i++)
  {
    Serial.printf("%dHz:%.1f,", audioInfo.getBandName(i), peaks[i]);
  }

  // also send the vu meter data
  Serial.printf("vuValue:%.1f,vuPeak:%.2f", vuMeter, vuMeterPeak);

  Serial.println();
}