Ben / moon

#include "audio.h"

#include "driver/i2s_std.h"
#include "freertos/FreeRTOS.h"
#include "esp_log.h"

#include "../src/moon.h"

static const char *TAG = "audio";

#define PIN_BCK   13
#define PIN_WS    14
#define PIN_DOUT  21

static i2s_chan_handle_t tx_chan;

void audio_init(void) {
    i2s_chan_config_t chan_cfg = I2S_CHANNEL_DEFAULT_CONFIG(I2S_NUM_0, I2S_ROLE_MASTER);
    ESP_ERROR_CHECK(i2s_new_channel(&chan_cfg, &tx_chan, NULL));

    i2s_std_config_t std_cfg = {
        .clk_cfg = I2S_STD_CLK_DEFAULT_CONFIG(44100),
        .slot_cfg = I2S_STD_PHILIPS_SLOT_DEFAULT_CONFIG(I2S_DATA_BIT_WIDTH_16BIT, I2S_SLOT_MODE_STEREO),
        .gpio_cfg = {
            .mclk = I2S_GPIO_UNUSED,
            .bclk = PIN_BCK,
            .ws = PIN_WS,
            .dout = PIN_DOUT,
            .din = I2S_GPIO_UNUSED,
            .invert_flags = {
                .mclk_inv = false,
                .bclk_inv = false,
                .ws_inv = false,
            },
        },
    };
    ESP_ERROR_CHECK(i2s_channel_init_std_mode(tx_chan, &std_cfg));
    ESP_ERROR_CHECK(i2s_channel_enable(tx_chan));

    ESP_LOGI(TAG, "I2S ready");
}

void audio_update(void) {
    static int16_t buf[1024 * 2];
    static int cnt = 0;
    size_t written;

    for (int i = 0; i < 1024; i++) {
        int16_t s = (cnt++ % 100 < 50) ? 32 : -32;
        buf[i * 2] = s;
        buf[i * 2 + 1] = s;
    }

    i2s_channel_write(tx_chan, buf, sizeof(buf), &written, portMAX_DELAY);
}