signal-generator/main/i2s_out.c

70 lines
1.9 KiB
C

#include "i2s_out.h"
#include "waveform.h"
#include "debug.h"
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "driver/i2s_std.h"
#include "driver/gpio.h"
#include "esp_log.h"
#define TAG "i2s_out"
#define BUF_FRAMES 480
#define PIN_BCLK GPIO_NUM_16
#define PIN_WS GPIO_NUM_15
#define PIN_DOUT GPIO_NUM_17
static i2s_chan_handle_t tx_handle;
void i2s_out_init(void)
{
i2s_chan_config_t chan_cfg = I2S_CHANNEL_DEFAULT_CONFIG(I2S_NUM_0, I2S_ROLE_MASTER);
chan_cfg.dma_frame_num = BUF_FRAMES;
ESP_ERROR_CHECK(i2s_new_channel(&chan_cfg, &tx_handle, NULL));
i2s_std_config_t std_cfg = {
.clk_cfg = I2S_STD_CLK_DEFAULT_CONFIG(SAMPLE_RATE),
.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_BCLK,
.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_handle, &std_cfg));
ESP_ERROR_CHECK(i2s_channel_enable(tx_handle));
ESP_LOGI(TAG, "I2S TX initialized: 48kHz 16-bit stereo, BCLK=%d WS=%d DOUT=%d",
PIN_BCLK, PIN_WS, PIN_DOUT);
}
static void i2s_out_task(void *arg)
{
int16_t buf[BUF_FRAMES * 2];
size_t bytes_written;
DBG("i2s_out_task started");
for (;;) {
for (int i = 0; i < BUF_FRAMES; i++) {
buf[i * 2] = waveform_next_sample(0);
buf[i * 2 + 1] = waveform_next_sample(1);
}
i2s_channel_write(tx_handle, buf, sizeof(buf), &bytes_written, portMAX_DELAY);
}
}
void i2s_out_start_task(void)
{
xTaskCreatePinnedToCore(i2s_out_task, "i2s_out", 4096, NULL, 10, NULL, 1);
}