Hi,
I am using nRF5340 for my unicast Audio server example where the nRF5340DK is the headset and my mobile device is the audio source. I have taken the unicast audio server example from the Zephyr. Since this DK do not have a I2S Decoder I am using an external I2S DAC (CJMCU-1334 UDA1334A I2S DAC Audio Stereo Decoder Module) . I have added overlay file for configuring the I2S peripheral as follows. I am using SDK 2.7.0
&pinctrl {
i2s0_default: i2s0_default {
group1 {
psels = <NRF_PSEL(I2S_SCK_M, 0, 15)>,
<NRF_PSEL(I2S_LRCK_M, 0, 12)>,
<NRF_PSEL(I2S_SDOUT, 0, 13)>,
<NRF_PSEL(I2S_SDIN, 0, 14)>;
};
};
};
&clock {
hfclkaudio-frequency = <11289600>;
};
&i2s0 {
status = "okay";
pinctrl-0 = <&i2s0_default>;
pinctrl-names = "default";
};
I have also made some changes in the main.c and also for initializing the I2S. The changed portions are also attaching .
#if defined(CONFIG_LIBLC3)
static void stream_recv_lc3_codec(struct bt_bap_stream *stream,
const struct bt_iso_recv_info *info,
struct net_buf *buf)
{
const uint8_t *in_buf;
uint8_t err = -1;
const int octets_per_frame = buf->len / frames_per_sdu;
void *tx_block;
size_t tx_size;
if (lc3_decoder == NULL) {
printk("LC3 decoder not setup, cannot decode data.\n");
return;
}
if ((info->flags & BT_ISO_FLAGS_VALID) == 0) {
printk("Bad packet: 0x%02X\n", info->flags);
in_buf = NULL;
} else {
in_buf = buf->data;
}
/* This code is to demonstrate the use of the LC3 codec. On an actual implementation
* it might be required to offload the processing to another task to avoid blocking the
* BT stack.
*/
for (int i = 0; i < frames_per_sdu; i++) {
int offset = 0;
err = lc3_decode(lc3_decoder, in_buf + offset, octets_per_frame,
LC3_PCM_FORMAT_S16, audio_buf, 1);
if (in_buf != NULL) {
offset += octets_per_frame;
}
}
printk("RX stream %p len %u\n", stream, buf->len);
if (err == 1) {
printk(" decoder performed PLC\n");
return;
} else if (err < 0) {
printk(" decoder failed - wrong parameters?\n");
return;
}
if (!i2s_configured) {
printk("Warning: I2S not configured, skipping audio output\n");
return;
}
/* Write decoded audio data to I2S */
err = i2s_buf_read(i2s_dev, &tx_block, &tx_size);
if (err < 0) {
printk("Failed to get I2S TX buffer: %d\n", err);
return;
}
/* Copy decoded audio data to TX block */
memcpy(tx_block, audio_buf, MIN(tx_size, sizeof(audio_buf)));
/* Send the audio data */
err = i2s_buf_write(i2s_dev, tx_block, MIN(tx_size, sizeof(audio_buf)));
if (err < 0) {
printk("Failed to write I2S TX buffer: %d\n", err);
return;
}
}
#include <zephyr/device.h>
#include <zephyr/drivers/i2s.h>
#include <zephyr/drivers/gpio.h>
#include <nrf.h>
/* Add these global variables for I2S */
static const struct device *i2s_dev;
#define NUM_SAMPLES 32
#define NUM_BLOCKS 8
static bool i2s_configured = false;
K_MEM_SLAB_DEFINE(i2s_tx_mem_slab, BT_ISO_SDU_BUF_SIZE(CONFIG_BT_ISO_TX_MTU) * 2, NUM_BLOCKS, NUM_SAMPLES);
static int init_i2s(void)
{
/* Configure I2S */
struct i2s_config i2s_cfg;
int ret;
/* Get I2S device */
i2s_dev = DEVICE_DT_GET(DT_NODELABEL(i2s0));
if (!device_is_ready(i2s_dev)) {
printk("I2S device not ready\n");
return -ENODEV;
}
/* Configure I2S TX */
i2s_cfg.word_size = 16;
i2s_cfg.channels = 2;
i2s_cfg.format = I2S_FMT_DATA_FORMAT_I2S;
i2s_cfg.options = I2S_OPT_FRAME_CLK_MASTER | I2S_OPT_BIT_CLK_MASTER;
i2s_cfg.frame_clk_freq = 48000;
i2s_cfg.block_size = BT_ISO_SDU_BUF_SIZE(CONFIG_BT_ISO_TX_MTU);
i2s_cfg.mem_slab = &i2s_tx_mem_slab;
i2s_cfg.timeout = 0;
ret = i2s_configure(i2s_dev, I2S_DIR_TX, &i2s_cfg);
if (ret < 0) {
printk("Failed to configure I2S TX: %d\n", ret);
return ret;
}
/* Start I2S TX */
ret = i2s_trigger(i2s_dev, I2S_DIR_TX, I2S_TRIGGER_START);
if (ret < 0) {
printk("Failed to start I2S TX: %d\n", ret);
return ret;
}
i2s_configured = true; // Set flag indicating I2S is configured
printk("I2S initialized successfully\n");
return 0;
}
with these changes I am able to build and flash the code to the nRF5340 Dk. I am able to connect with the mobile device with the DK as a audio device, but i have faced some errors at the starting. The errors are also attached.
Ignoring the first error I connected the device and when I played audio in the source , the error in the below screenshot happened causing the system halt.
I understand the errors happened due to some memory buffer issues. But couldn't able to point out the exact point.