ESP32 max98357a audio output

Hardware connection

小智AI终端DIY面包板WIFI-LCD彩屏接线教程

• VCC: 3.3v
• GND: GND
• BCLK: I2S位时钟引脚，GPIO 15
• LRC: I2S左右声道时钟引脚，GPIO 16
• DIN: I2S数据输出引脚，GPIO 7
• SD: 悬空
• GAIN: 悬空（默认3dB增益）或接3.3V（15dB增益）。

I2s

#define I2S_BCLK 15
#define I2S_LRC 16
#define I2S_DOUT 7

static void configure_speaker()
{
    i2s_config_t i2s_config = {
        .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_TX),
        .sample_rate = 44100,
        .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 = 0,
        .dma_buf_count = 8,
        .dma_buf_len = 64,
        .use_apll = false,
        .tx_desc_auto_clear = true};

    i2s_pin_config_t pin_config = {
        .bck_io_num = I2S_BCLK,
        .ws_io_num = I2S_LRC,
        .data_out_num = I2S_DOUT,
        .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);
}

Play test sound:

void generate_test_sound()
{
    size_t bytes_written;
    for (uint32_t i = 0; i < audio_length; i++) {
        // 从Flash读取数据（无需pgmspace.h）
        int16_t sample;
        memcpy(&sample, &audio_data[i], sizeof(sample)); // 安全读取方式

        // 发送立体声数据
        int16_t stereo_sample[2] = {sample, sample};
        i2s_write(I2S_NUM_0, stereo_sample, sizeof(stereo_sample), &bytes_written, portMAX_DELAY);
    }
}