ret_code_t i2s_ws2812b_drive_xfer(rgb_led_t *led_array, uint16_t num_leds, uint8_t drive_pin)
{
ret_code_t err_code;
// define configs
nrf_drv_i2s_config_t config = NRF_DRV_I2S_DEFAULT_CONFIG;
config.sck_pin = 22; // Don't set NRF_DRV_I2S_PIN_NOT_USED for I2S_CONFIG_SCK_PIN. (The program will stack.)
config.lrck_pin = NRF_DRV_I2S_PIN_NOT_USED;
config.mck_pin = NRF_DRV_I2S_PIN_NOT_USED;
config.sdout_pin = drive_pin;
config.sdin_pin = NRF_DRV_I2S_PIN_NOT_USED;
config.irq_priority = APP_IRQ_PRIORITY_HIGH;
config.mode = NRF_I2S_MODE_MASTER;
config.format = NRF_I2S_FORMAT_I2S;
config.alignment = NRF_I2S_ALIGN_LEFT;
config.sample_width = NRF_I2S_SWIDTH_16BIT;
config.channels = NRF_I2S_CHANNELS_STEREO;
config.mck_setup = NRF_I2S_MCK_32MDIV10;
config.ratio = NRF_I2S_RATIO_32X;
// initialize i2s
err_code = nrf_drv_i2s_init(&config, i2s_ws2812b_drive_handler);
APP_ERROR_CHECK(err_code);
if ( err_code != NRF_SUCCESS )
{
return err_code;
}
// start transfer
uint16_t tx_buffer_size = num_leds * I2S_WS2812B_DRIVE_BUF_SIZE_PER_LED / 4;
uint32_t m_buffer_tx[tx_buffer_size];
i2s_ws2812b_drive_tx_led_array = led_array;
i2s_ws2812b_drive_m_blocks_transferred = 0;
i2s_ws2812b_drive_flag_first_buffer = true;
err_code = nrf_drv_i2s_start(NULL, m_buffer_tx, tx_buffer_size * 2, 0);
APP_ERROR_CHECK(err_code);
if ( err_code != NRF_SUCCESS )
{
return err_code;
}
nrf_delay_us((num_leds+20) * (24*5/4));
// stop transfer
nrf_drv_i2s_stop();
// un-initialize i2s
nrf_drv_i2s_uninit();
return NRF_SUCCESS;
}
int main(void)
{
uint32_t err_code = NRF_SUCCESS;
LEDS_CONFIGURE(LED_MASK_OK | LED_MASK_ERROR);
init_uart();
printf("\r\n"
"I2S loopback example\r\n");
nrf_drv_i2s_config_t config = NRF_DRV_I2S_DEFAULT_CONFIG;
// In Master mode the MCK frequency and the MCK/LRCK ratio should be
// set properly in order to achieve desired audio sample rate (which
// is equivalent to the LRCK frequency).
// For the following settings we'll get the LRCK frequency equal to
// 15873 Hz (the closest one to 16 kHz that is possible to achieve).
config.mck_setup = NRF_I2S_MCK_32MDIV21;
config.ratio = NRF_I2S_RATIO_96X;
err_code = nrf_drv_i2s_init(&config, data_handler);
APP_ERROR_CHECK(err_code);
for (;;)
{
memset(m_buffer_rx, 0xCC, sizeof(m_buffer_rx));
m_blocks_transferred = 0;
err_code = nrf_drv_i2s_start(m_buffer_rx, m_buffer_tx,
I2S_BUFFER_SIZE, 0);
APP_ERROR_CHECK(err_code);
while (m_blocks_transferred < BLOCKS_TO_TRANSFER)
{}
nrf_drv_i2s_stop();
LEDS_OFF(LED_MASK_OK | LED_MASK_ERROR);
nrf_delay_ms(PAUSE_TIME);
}
}
