ESP32-I2S-sinewave.ino

#include <driver/i2s.h>
#include <math.h>

// ─── กำหนดขา I2S ───────────────────────────────────────
#define I2S_BCK_PIN   26   // Bit Clock
#define I2S_WS_PIN    25   // Word Select (LRCK)
#define I2S_DATA_PIN  22   // Data Out → DIN ของโมดูล

// ─── พารามิเตอร์เสียง ────────────────────────────────────
#define SAMPLE_RATE   44100
#define FREQUENCY     440       // ความถี่เสียง (Hz) -- A4
#define AMPLITUDE     28000     // ระดับความดัง (Max = 32767)
#define BUFFER_SIZE   256

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

  // ─── ตั้งค่า I2S ─────────────────────────────────────
  i2s_config_t i2s_config = {
    .mode                 = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_TX),
    .sample_rate          = SAMPLE_RATE,
    .bits_per_sample      = I2S_BITS_PER_SAMPLE_16BIT,
    .channel_format       = I2S_CHANNEL_FMT_RIGHT_LEFT,
    .communication_format = I2S_COMM_FORMAT_STAND_I2S,
    .intr_alloc_flags     = ESP_INTR_FLAG_LEVEL1,
    .dma_buf_count        = 8,
    .dma_buf_len          = BUFFER_SIZE,
    .use_apll             = false,
    .tx_desc_auto_clear   = true
  };

  i2s_pin_config_t pin_config = {
    .bck_io_num   = I2S_BCK_PIN,
    .ws_io_num    = I2S_WS_PIN,
    .data_out_num = I2S_DATA_PIN,
    .data_in_num  = I2S_PIN_NO_CHANGE
  };

  i2s_driver_install(I2S_NUM_0, &i2s_config, 0, NULL);
  i2s_set_pin(I2S_NUM_0, &pin_config);
  i2s_zero_dma_buffer(I2S_NUM_0);

  Serial.println("I2S Initialized — Playing Sine Wave...");
}

void loop() {
  int16_t buffer[BUFFER_SIZE * 2];  // Stereo: L + R
  size_t bytes_written;

  for (int i = 0; i < BUFFER_SIZE; i++) {
    int16_t sample = (int16_t)(AMPLITUDE * sin(2.0 * M_PI * FREQUENCY * i / SAMPLE_RATE));
    buffer[i * 2]     = sample;  // Left Channel
    buffer[i * 2 + 1] = sample;  // Right Channel
  }

  i2s_write(I2S_NUM_0, buffer, sizeof(buffer), &bytes_written, portMAX_DELAY);
}