I2S Audio on the ESP32-S3

				
					#include <driver/i2s.h>

#define I2S_SPK_BCLK 2
#define I2S_SPK_LRC  1
#define I2S_SPK_DOUT 38

#define I2S_SD_SPK 4
#define I2S_SPKR_PORT I2S_NUM_0

#define BUTTON 12

const int sampleRate = 44100;     // Hz
const int frequency = 1000;       // Hz
const int amplitude = 1000;       // -amplitude +amplitude 
const int samplesPerCycle = sampleRate / frequency;

int16_t waveBuffer[samplesPerCycle];  // store 1 cycle of triangular wave

void generateTriangularWave() {
  for (int i = 0; i < samplesPerCycle; ++i) {
    float phase = (float)i / samplesPerCycle;
    float value = (phase < 0.5) ? (2 * phase) : (2 * (1 - phase));
    waveBuffer[i] = (int16_t)((value * 2 - 1) * amplitude); // Scale to [-amplitude, amplitude]
  }
}

void setupI2S() {
  const i2s_config_t i2s_config = {
    .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_TX),
    .sample_rate = sampleRate,
    .bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT,
    .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
    .communication_format = I2S_COMM_FORMAT_I2S_MSB,
    .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
    .dma_buf_count = 8,
    .dma_buf_len = 32,
    .use_apll = false,
    .tx_desc_auto_clear = true,
    .fixed_mclk = 0
  };

  const i2s_pin_config_t pin_config = {
    .bck_io_num = I2S_SPK_BCLK,
    .ws_io_num = I2S_SPK_LRC,
    .data_out_num = I2S_SPK_DOUT,
    .data_in_num = I2S_PIN_NO_CHANGE
  };

  i2s_driver_install(I2S_SPKR_PORT, &i2s_config, 0, NULL);
  i2s_set_pin(I2S_SPKR_PORT, &pin_config);
}

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

  pinMode(BUTTON, INPUT_PULLUP);  // start stop button  
  pinMode(I2S_SD_SPK, OUTPUT);    // SPKR Shutdown Pin

  generateTriangularWave();       // traingle wave 1-cycle function
  setupI2S();
}

uint8_t toggle = 0;

void loop() {
  
  size_t bytesWritten;
  
  if(digitalRead(BUTTON) == 0){
    delay(300);   // debounce
    toggle ^= 1;
    Serial.println("Button Pressed");

    if(toggle){
      Serial.println("Audio ON");
      digitalWrite(I2S_SD_SPK, HIGH); // turn ON speaker
    }else{
      Serial.println("Audio OFF");
      digitalWrite(I2S_SD_SPK, LOW);  // turn OFF speaker
    }
  }
  
  // write I2S data to DMA (1 Traingular Wave cycle)
  if(toggle){
    if(i2s_write(I2S_NUM_0, waveBuffer, sizeof(waveBuffer), &bytesWritten, portMAX_DELAY) == ESP_OK){
      Serial.print("OK"); Serial.println(bytesWritten);
    }else{
      Serial.println("Failed");
      while(1);
    }
    
  }

}