Datasheet

ManualsBrandsAdafruit ManualsAdafruitI2S MEMS Microphone

by Sandeep Mistry

#include <I2S.h>

void setup() {

// Open serial communications and wait for port to open:

// A baud rate of 115200 is used instead of 9600 for a faster data rate

// on non-native USB ports

Serial.begin(115200);

while (!Serial) {

; // wait for serial port to connect. Needed for native USB port only

}

// start I2S at 16 kHz with 32-bits per sample

if (!I2S.begin(I2S_PHILIPS_MODE, 16000, 32)) {

Serial.println("Failed to initialize I2S!");

while (1); // do nothing

}

#define SAMPLES 128 // make it a power of two for best DMA performance

void loop() {

// read a bunch of samples:

int samples[SAMPLES];

for (int i=0; i<SAMPLES; i++) {

int sample = 0;

while ((sample == 0) || (sample == -1) ) {

sample = I2S.read();

}

// convert to 18 bit signed

sample >>= 14;

samples[i] = sample;

}

// ok we hvae the samples, get the mean (avg)

float meanval = 0;

for (int i=0; i<SAMPLES; i++) {

meanval += samples[i];

}

meanval /= SAMPLES;

//Serial.print("# average: " ); Serial.println(meanval);

// subtract it from all sapmles to get a 'normalized' output

for (int i=0; i<SAMPLES; i++) {

samples[i] -= meanval;

//Serial.println(samples[i]);

}

// find the 'peak to peak' max

float maxsample, minsample;

minsample = 100000;

maxsample = -100000;

for (int i=0; i<SAMPLES; i++) {

minsample = min(minsample, samples[i]);

maxsample = max(maxsample, samples[i]);

}

Serial.println(maxsample - minsample);