Hello, I use nrf52832 (SDK 17) and I wanna send sounds from a microphone (which uses PDM) to TAS2521 which is connected to a headphone and it uses I2S. here is my code to initialize TAS2521 by SPI:
uint8_t tas2521_regRead(uint8_t regAddress) {
uint8_t SPI_TX_Buff[1] = {(regAddress << 1) | 1};
uint8_t SPI_RX_Buff[2] = {0, 0};
nrf_gpio_pin_clear(SPI_AMP_SS_PIN);
spi_xfer_done = false;
APP_ERROR_CHECK(nrf_drv_spi_transfer(&spi, SPI_TX_Buff, 1, SPI_RX_Buff, 2));
while (!spi_xfer_done) {
__WFE();
}
nrf_gpio_pin_set(SPI_AMP_SS_PIN);
return SPI_RX_Buff[1];
}
void tas2521_regWrite(uint8_t regAddress, uint8_t value) {
uint8_t SPI_TX_Buff[2] = {(regAddress << 1) | 0, value};
nrf_gpio_pin_clear(SPI_AMP_SS_PIN);
spi_xfer_done = false;
APP_ERROR_CHECK(nrf_drv_spi_transfer(&spi, SPI_TX_Buff, 2, NULL, 0));
while (!spi_xfer_done) {
__WFE();
}
nrf_gpio_pin_set(SPI_AMP_SS_PIN);
}
void tas2521_pageSwitch(uint8_t page) {
tas2521_regWrite(0, page);
}
void tas2521_softReset() {
tas2521_pageSwitch(0);
tas2521_regWrite(0x01, 0x01);
}
void tas2521_ldoSet() {
tas2521_pageSwitch(1);
tas2521_regWrite(0x02, 0x00);
}
void tas2521_powerUp() {
tas2521_pageSwitch(0);
tas2521_regWrite(0x04, 0x00);
tas2521_regWrite(0x0B, 0x81);
tas2521_regWrite(0x0C, 0x82);
tas2521_regWrite(0x0D, 0x00);
tas2521_regWrite(0x0E, 0x80);
tas2521_regWrite(0x1B, 0x00);
tas2521_regWrite(0x1C, 0x00);
tas2521_regWrite(0x3C, 0x02);
tas2521_pageSwitch(1);
tas2521_regWrite(0x01, 0x10);
tas2521_regWrite(0x0A, 0x00);
tas2521_regWrite(0x0C, 0x08);
tas2521_regWrite(0x16, 0x00);
tas2521_regWrite(0x09, 0x20);
tas2521_regWrite(0x10, 0x00);
tas2521_pageSwitch(0);
tas2521_regWrite(0x3F, 0x90);
tas2521_regWrite(0x41, 0x00);
tas2521_regWrite(0x40, 0x04);
}
and in the main() function I initialized SPI and use these functions:
nrf_drv_spi_config_t spi_config = NRF_DRV_SPI_DEFAULT_CONFIG;
spi_config.frequency = NRF_DRV_SPI_FREQ_1M; //Check 1MHz
spi_config.mode = NRF_DRV_SPI_MODE_1;
spi_config.bit_order = NRF_DRV_SPI_BIT_ORDER_MSB_FIRST;
spi_config.ss_pin = NRF_DRV_SPI_PIN_NOT_USED; //Select Slave
spi_config.miso_pin = SPI_MISO_PIN;
spi_config.mosi_pin = SPI_MOSI_PIN;
spi_config.sck_pin = SPI_SCK_PIN;
spi_config.irq_priority = APP_IRQ_PRIORITY_HIGH;
err_code = nrf_drv_spi_init(&spi, &spi_config, spi_event_handler, NULL);
APP_ERROR_CHECK(err_code);
nrf_gpio_cfg_output(SPI_AMP_SS_PIN);
nrf_gpio_pin_set(SPI_AMP_SS_PIN);
tas2521_softReset();
tas2521_ldoSet();
tas2521_powerUp();
I also Initialized I2S after that:
nrf_drv_i2s_config_t i2s_config = NRF_DRV_I2S_DEFAULT_CONFIG;
i2s_config.sdin_pin = I2S_SDIN_PIN;
i2s_config.mck_pin = I2S_MCK_PIN;
i2s_config.sck_pin = I2S_BCK_PIN;
i2s_config.lrck_pin = I2S_WCK_PIN;
i2s_config.sdout_pin = I2S_SDOUT_PIN;
i2s_config.mck_setup = NRF_I2S_MCK_32MDIV32;
i2s_config.ratio = NRF_I2S_RATIO_96X;
i2s_config.sample_width = NRF_I2S_SWIDTH_16BIT;
i2s_config.channels = NRF_I2S_CHANNELS_LEFT;
err_code = nrf_drv_i2s_init(&i2s_config, i2s_data_handler);
APP_ERROR_CHECK(err_code);
nrf_drv_i2s_buffers_t const initial_buffers = {
.p_tx_buffer = i2s_buffer_tx[0],
.p_rx_buffer = i2s_buffer_rx[0],
};
err_code = nrf_drv_i2s_start(&initial_buffers, PDM_BUFFER_SIZE_SAMPLES, 0);
APP_ERROR_CHECK(err_code);
PDM microphone works fine (I checked it) and PDM_BUFFER_SIZE_SAMPLES is equal to 125. I also use these functions for I2S:
static void i2s_data_handler(nrf_drv_i2s_buffers_t const *p_released,
uint32_t status) {
ASSERT(p_released);
if (!(status & NRFX_I2S_STATUS_NEXT_BUFFERS_NEEDED)) {
return;
}
if (!p_released->p_rx_buffer) {
for (uint16_t i = 0; i < PDM_BUFFER_SIZE_SAMPLES; i++) {
i2s_buffer_tx[0][i] = i2s_buffer_tx[1][i];
}
nrf_drv_i2s_buffers_t const next_buffers = {
.p_rx_buffer = i2s_buffer_rx[0],
.p_tx_buffer = i2s_buffer_tx[0],
};
APP_ERROR_CHECK(nrf_drv_i2s_next_buffers_set(&next_buffers));
} else {
APP_ERROR_CHECK(nrf_drv_i2s_next_buffers_set(p_released));
}
}
static void prepare_tx_data(uint16_t p_block[]) {
for (uint16_t i = 0; i < PDM_BUFFER_SIZE_SAMPLES; i++) {
p_block[i] = pdm_buffer[i];
}
}
Whenever pdm_event_handler function indicates that 125 samples are ready it calls prepare_tx_data(i2s_buffer_tx[1]).
I can hear some sounds from headphones, but it is very distorted and noisy, It is possible to help me?
