NRF5340 audio stream bidirectional problem

Question

Hello Nordic Team,

I am working on a LE Audio project on NCS v2.9.0. My development board is nrf5340-dk. I am using unicast client example and I am trying to use it with my earbuds. I am using Samsung Galaxy Buds 2 Pro. Strangely, it is not able to remember pair information. So, I made some changes inside project to forget boding information after disconnect or reset condition. Without these additions, it is impossible to test it.

My problem is this, without CONFIG_STREAM_BIDIRECTIONAL enabled, it is working expected. I am able to get usb audio data to my earbuds. This is the logs about discovering process.

However, if I enabled CONFIG_STREAM_BIDIRECTIONAL flag, I am not able to send or receive any audio data with my earbuds. Strangely, the code stays like this below and I feel there is a problem while discovering earbuds.

Is this possible to use bidirectional audio over usb? Or, I am trying something impossible.

Thanks.

dejans · Accepted Answer

Hi, There is a workaround for your reported issue when using CONFIG_STREAM_BIDIRECTIONAL=y

Fullscreen 
 cis_bidir_bud2_fix.diff 
 Download 
 
 diff --git a/applications/nrf5340_audio/prj.conf b/applications/nrf5340_audio/prj.conf
index b1dc911a59..6294fa3c42 100644
--- a/applications/nrf5340_audio/prj.conf
+++ b/applications/nrf5340_audio/prj.conf
@@ -69,3 +69,6 @@ CONFIG_SD_LOG_LEVEL_OFF=y
 
 # Suppress LOG_INF messages from hci_core
 CONFIG_BT_HCI_CORE_LOG_LEVEL_WRN=y
+CONFIG_BT_DEVICE_NAME="Galaxy Buds2 Pro"
+CONFIG_BT_BONDABLE=n
+CONFIG_STREAM_BIDIRECTIONAL=y
diff --git a/applications/nrf5340_audio/src/bluetooth/Kconfig b/applications/nrf5340_audio/src/bluetooth/Kconfig
index 2bb2d8d206..1bb692aa1a 100644
--- a/applications/nrf5340_audio/src/bluetooth/Kconfig
+++ b/applications/nrf5340_audio/src/bluetooth/Kconfig
@@ -38,7 +38,7 @@ choice BT_AUDIO_PREF_SAMPLE_RATE
 default BT_AUDIO_PREF_SAMPLE_RATE_16KHZ if BT_BAP_BROADCAST_16_2_1
 default BT_AUDIO_PREF_SAMPLE_RATE_16KHZ if BT_BAP_BROADCAST_16_2_2
 default BT_AUDIO_PREF_SAMPLE_RATE_16KHZ if BT_BAP_UNICAST_16_2_1
-	default BT_AUDIO_PREF_SAMPLE_RATE_24KHZ if STREAM_BIDIRECTIONAL
+	default BT_AUDIO_PREF_SAMPLE_RATE_16KHZ if STREAM_BIDIRECTIONAL
 default BT_AUDIO_PREF_SAMPLE_RATE_24KHZ if BT_BAP_BROADCAST_24_2_1
 default BT_AUDIO_PREF_SAMPLE_RATE_24KHZ if BT_BAP_BROADCAST_24_2_2
 default BT_AUDIO_PREF_SAMPLE_RATE_24KHZ if BT_BAP_UNICAST_24_2_1
diff --git a/applications/nrf5340_audio/src/bluetooth/bt_stream/unicast/unicast_client.c b/applications/nrf5340_audio/src/bluetooth/bt_stream/unicast/unicast_client.c
index 26aabe4b25..384a305e85 100644
--- a/applications/nrf5340_audio/src/bluetooth/bt_stream/unicast/unicast_client.c
+++ b/applications/nrf5340_audio/src/bluetooth/bt_stream/unicast/unicast_client.c
@@ -98,7 +98,7 @@ static struct bt_bap_lc3_preset lc3_preset_sink_48_4_1 = BT_BAP_LC3_UNICAST_PRES
 static struct bt_bap_lc3_preset lc3_preset_sink_24_2_1 = BT_BAP_LC3_UNICAST_PRESET_24_2_1(
 BT_AUDIO_LOCATION_ANY, (BT_AUDIO_CONTEXT_TYPE_UNSPECIFIED));
 static struct bt_bap_lc3_preset lc3_preset_sink_16_2_1 = BT_BAP_LC3_UNICAST_PRESET_16_2_1(
-	BT_AUDIO_LOCATION_ANY, (BT_AUDIO_CONTEXT_TYPE_UNSPECIFIED));
+	BT_AUDIO_LOCATION_ANY, (BT_AUDIO_CONTEXT_TYPE_UNSPECIFIED|BT_AUDIO_CONTEXT_TYPE_CONVERSATIONAL));
 
 static struct bt_bap_lc3_preset lc3_preset_source = BT_BAP_LC3_UNICAST_PRESET_NRF5340_AUDIO_SOURCE;
 static struct bt_bap_lc3_preset lc3_preset_source_48_4_1 =
@@ -106,7 +106,7 @@ static struct bt_bap_lc3_preset lc3_preset_source_48_4_1 =
 static struct bt_bap_lc3_preset lc3_preset_source_24_2_1 =
 BT_BAP_LC3_UNICAST_PRESET_24_2_1(BT_AUDIO_LOCATION_ANY, BT_AUDIO_CONTEXT_TYPE_UNSPECIFIED);
 static struct bt_bap_lc3_preset lc3_preset_source_16_2_1 =
-	BT_BAP_LC3_UNICAST_PRESET_16_2_1(BT_AUDIO_LOCATION_ANY, BT_AUDIO_CONTEXT_TYPE_UNSPECIFIED);
+	BT_BAP_LC3_UNICAST_PRESET_16_2_1(BT_AUDIO_LOCATION_ANY, (BT_AUDIO_CONTEXT_TYPE_UNSPECIFIED|BT_AUDIO_CONTEXT_TYPE_CONVERSATIONAL));
 
 static bool playing_state = true;
 
@@ -635,15 +635,15 @@ static bool source_parse_cb(struct bt_data *data, void *user_data)
 break;
 }
 
- /* If no match with the preferred, revert to trying highest first */
- if (lc3_freq_bit & BT_AUDIO_CODEC_CAP_FREQ_48KHZ) {
- lc3_preset_source = lc3_preset_source_48_4_1;
+ /* If no match with the preferred, revert to trying lowest first */
+ if (lc3_freq_bit & BT_AUDIO_CODEC_CAP_FREQ_16KHZ) {
+ lc3_preset_source = lc3_preset_source_16_2_1;
 *(bool *)user_data = true;
 } else if (lc3_freq_bit & BT_AUDIO_CODEC_CAP_FREQ_24KHZ) {
 lc3_preset_source = lc3_preset_source_24_2_1;
 *(bool *)user_data = true;
- } else if (lc3_freq_bit & BT_AUDIO_CODEC_CAP_FREQ_16KHZ) {
- lc3_preset_source = lc3_preset_source_16_2_1;
+ } else if (lc3_freq_bit & BT_AUDIO_CODEC_CAP_FREQ_48KHZ) {
+ lc3_preset_source = lc3_preset_source_48_4_1;
 *(bool *)user_data = true;
 }

Best regards, Dejan

NRF5340 audio stream bidirectional problem

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