esp32s3_i2s_simple_sine.ino

// esp32s3_i2s_simple_sine.ino
// demonstrate I2S on ESP32S3
// origally from guiguig on Discord: https://discord.com/channels/327254708534116352/422210663507558401/1240067408660795424
// video demo below in comment

#include <I2S.h>

#define BCK  16  // feather esp32s3 A2
#define DOUT 17  // feather esp32s3 A1
#define LCK  18  // feather esp32s3 A0

double t = 0.0;
double frequency = 440.0;
int sampleRate = 22500;
//int sampleRate = 44100; // not acheiveable without DMA
double amplitude = 2048.0;
double value;

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

  // Set I2S output pins
  I2S.setAllPins(/* BitClkPin */ BCK, /* LRClkPin */ LCK, /* dataOutPin */ DOUT, /* dataInPin */ -1, /* mclkPin */ -1);

  if (!I2S.begin(I2S_PHILIPS_MODE, sampleRate, 16)) {
    while (1) {
      Serial.println("Failed to initialize I2S!");
      delay(100);
    }
  }
}

uint32_t last_time = 0;

void loop() {
  if( millis() - last_time > 500 )  {
    last_time = millis();
    frequency = random(220, 440);
    Serial.print("new frequency "); Serial.println(frequency);
  }

  // Sine wave waveform
  value = sin(2.0 * PI * frequency * t);

  // // Write both channel's samples
  I2S.write((short)(value * amplitude));
  I2S.write((short)(value * amplitude));

  t += 1.0 / (double)sampleRate;
}

Video demo:

IMG_3826.mov

The Arduino setup used was this. The board was generic "ESP32S3 Dev Module" because I was having issues with the Adafruit ESP32S3 Feather board variant. Using the generic means I had to put the board in USB Bootloader mode (BOOT + RESET button) before every upload and press RESET to start the sketch