bugfix/1025-local-link-lost-connection (#34)

Fixes the bug that local link loses connection after a few minutes.

Openproject:
#1025
#608

Reviewed-on: #34

.gitignore

@@ -51,4 +51,11 @@ src/auracast/available_samples.txt
 src/auracast/server/stream_settings2.json
 src/scripts/temperature_log*
 
-src/auracast/server/recordings/
+src/auracast/server/recordings/
+src/auracast/server/led_settings.json
+
+
+# Dante license files
+*.lic
+src/dep/dante_package/dante_data/activation/device.lic
+src/dep/dante_package/dante_data/activation/manufacturer.cert

poetry.lock

@@ -270,51 +270,6 @@ optional = false
 python-versions = ">=3.9"
 groups = ["main"]
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     {file = "av-14.4.0.tar.gz", hash = "sha256:3ecbf803a7fdf67229c0edada0830d6bfaea4d10bfb24f0c3f4e607cd1064b42"},
 ]
 
@@ -1849,6 +1804,22 @@ files = [
     {file = "protobuf-6.30.2.tar.gz", hash = "sha256:35c859ae076d8c56054c25b59e5e59638d86545ed6e2b6efac6be0b6ea3ba048"},
 ]
 
+[[package]]
+name = "pyalsaaudio"
+version = "0.11.0"
+description = "ALSA bindings"
+optional = false
+python-versions = "*"
+groups = ["main"]
+files = []
+develop = false
+
+[package.source]
+type = "git"
+url = "ssh://git@gitea.summitwave.work:222/auracaster/sw_pyalsaaudio.git"
+reference = "b3d11582e03df6929b2e7acbaa1306afc7b8a6bc"
+resolved_reference = "b3d11582e03df6929b2e7acbaa1306afc7b8a6bc"
+
 [[package]]
 name = "pyarrow"
 version = "20.0.0"
@@ -2443,6 +2414,22 @@ files = [
     {file = "rpds_py-0.25.1.tar.gz", hash = "sha256:8960b6dac09b62dac26e75d7e2c4a22efb835d827a7278c34f72b2b84fa160e3"},
 ]
 
+[[package]]
+name = "rpi-gpio"
+version = "0.7.1"
+description = "A module to control Raspberry Pi GPIO channels"
+optional = false
+python-versions = "*"
+groups = ["main"]
+files = [
+    {file = "RPi.GPIO-0.7.1-cp27-cp27mu-linux_armv6l.whl", hash = "sha256:b86b66dc02faa5461b443a1e1f0c1d209d64ab5229696f32fb3b0215e0600c8c"},
+    {file = "RPi.GPIO-0.7.1-cp310-cp310-linux_armv6l.whl", hash = "sha256:57b6c044ef5375a78c8dda27cdfadf329e76aa6943cd6cffbbbd345a9adf9ca5"},
+    {file = "RPi.GPIO-0.7.1-cp37-cp37m-linux_armv6l.whl", hash = "sha256:77afb817b81331ce3049a4b8f94a85e41b7c404d8e56b61ac0f1eb75c3120868"},
+    {file = "RPi.GPIO-0.7.1-cp38-cp38-linux_armv6l.whl", hash = "sha256:29226823da8b5ccb9001d795a944f2e00924eeae583490f0bc7317581172c624"},
+    {file = "RPi.GPIO-0.7.1-cp39-cp39-linux_armv6l.whl", hash = "sha256:15311d3b063b71dee738cd26570effc9985a952454d162937c34e08c0fc99902"},
+    {file = "RPi.GPIO-0.7.1.tar.gz", hash = "sha256:cd61c4b03c37b62bba4a5acfea9862749c33c618e0295e7e90aa4713fb373b70"},
+]
+
 [[package]]
 name = "samplerate"
 version = "0.2.2"
@@ -2976,4 +2963,4 @@ test = ["pytest", "pytest-asyncio"]
 [metadata]
 lock-version = "2.1"
 python-versions = ">=3.11"
-content-hash = "3c9f92c7a5af40f98da9c7824d9c2a6f7eb809e91e43cfef4995761b2e887256"
+content-hash = "7bccf2978170ead195e1e8cff151823a5276823195a239622186fcec830154d9"

pyproject.toml

@@ -17,7 +17,9 @@ dependencies = [
     "sounddevice (>=0.5.2,<0.6.0)",
     "python-dotenv (>=1.1.1,<2.0.0)",
     "smbus2 (>=0.5.0,<0.6.0)",
-    "samplerate (>=0.2.2,<0.3.0)"
+    "samplerate (>=0.2.2,<0.3.0)",
+    "rpi-gpio (>=0.7.1,<0.8.0)",
+    "pyalsaaudio @ git+ssh://git@gitea.summitwave.work:222/auracaster/sw_pyalsaaudio.git@b3d11582e03df6929b2e7acbaa1306afc7b8a6bc"
 ]
 
 [project.optional-dependencies]

src/auracast/auracast_config.py

@@ -1,5 +1,11 @@
 from typing import List
-from pydantic import BaseModel
+from pydantic import BaseModel, field_validator
+
+# Discrete TX power levels (dBm) supported by the Nordic SoftDevice Controller
+# for the nRF radio PA. The HCI controller will clamp requested values to the
+# nearest supported step. The maximum is bounded by CONFIG_BT_CTLR_TX_PWR_*
+# in the hci_uart firmware (currently +8 dBm).
+TX_POWER_VALID = [8, 7, 6, 5, 4, 3, 2, 0, -4, -8, -12, -16, -20]
 
 # Define some base to hold the relevant parameters
 class AuracastQoSConfig(BaseModel):
@@ -28,13 +34,24 @@ class AuracastGlobalConfig(BaseModel):
     octets_per_frame: int = 40 #48kbps@24kHz # bitrate = octets_per_frame * 8 / frame len
     frame_duration_us: int = 10000
     presentation_delay_us: int = 40000
-    # TODO:pydantic does not support bytes serialization - use .hex and np.fromhex()
-    manufacturer_data: tuple[int, bytes] | tuple[None, None] = (None, None)
     # LE Audio: Broadcast Audio Immediate Rendering (metadata type 0x09)
     # When true, include a zero-length LTV with type 0x09 in the subgroup metadata
     # so receivers may render earlier than the presentation delay for lower latency.
     immediate_rendering: bool = False
     assisted_listening_stream: bool = False
+    # Bluetooth advertising TX power for this radio in dBm (per advertising set).
+    # Sent through HCI_LE_Set_Extended_Advertising_Parameters; the SDC clamps to
+    # nearest supported hardware step and propagates to primary/secondary adv,
+    # the periodic advertising train and the BIS ISO PDUs.
+    advertising_tx_power: int = 8
+
+    @field_validator('advertising_tx_power')
+    @classmethod
+    def _snap_tx_power(cls, v: int) -> int:
+        # Snap to the nearest supported discrete step in TX_POWER_VALID.
+        if v in TX_POWER_VALID:
+            return v
+        return min(TX_POWER_VALID, key=lambda s: abs(s - v))
 
 # "Audio input. "
 # "'device' -> use the host's default sound input device, "
@@ -55,7 +72,6 @@ class AuracastBigConfig(BaseModel):
     precode_wav: bool = False
     iso_que_len: int = 64
     num_bis: int = 1  # 1 = mono (FRONT_LEFT), 2 = stereo (FRONT_LEFT + FRONT_RIGHT)
-    input_gain_db: float = 0.0  # Software gain boost in dB applied before LC3 encoding (0 = off, max 20)
 
 class AuracastBigConfigDeu(AuracastBigConfig):
     id: int = 12
@@ -63,7 +79,7 @@ class AuracastBigConfigDeu(AuracastBigConfig):
     name: str = 'Hörsaal A'
     language: str ='deu'
     program_info: str = 'Vorlesung DE'
-    audio_source: str = 'file:./testdata/wave_particle_5min_de.wav'
+    audio_source: str = 'file:./testdata/wave_particle_5min_de.lc3'
 
 class AuracastBigConfigEng(AuracastBigConfig):
     id: int = 123
@@ -71,7 +87,7 @@ class AuracastBigConfigEng(AuracastBigConfig):
     name: str  = 'Lecture Hall A'
     language: str ='eng'
     program_info: str = 'Lecture EN'
-    audio_source: str  = 'file:./testdata/wave_particle_5min_en.wav'
+    audio_source: str  = 'file:./testdata/wave_particle_5min_en.lc3'
 
 class AuracastBigConfigFra(AuracastBigConfig):
     id: int = 1234
@@ -80,7 +96,7 @@ class AuracastBigConfigFra(AuracastBigConfig):
     name: str  = 'Auditoire A'
     language: str ='fra'
     program_info: str = 'Auditoire FR'
-    audio_source: str  = 'file:./testdata/wave_particle_5min_fr.wav'
+    audio_source: str  = 'file:./testdata/wave_particle_5min_fr.lc3'
 
 class AuracastBigConfigSpa(AuracastBigConfig):
     id: int =12345
@@ -88,7 +104,7 @@ class AuracastBigConfigSpa(AuracastBigConfig):
     name: str  = 'Auditorio A'
     language: str ='spa'
     program_info: str = 'Auditorio ES'
-    audio_source: str  = 'file:./testdata/wave_particle_5min_es.wav'
+    audio_source: str  = 'file:./testdata/wave_particle_5min_es.lc3'
 
 class AuracastBigConfigIta(AuracastBigConfig):
     id: int =1234567
@@ -96,7 +112,7 @@ class AuracastBigConfigIta(AuracastBigConfig):
     name: str  = 'Aula A'
     language: str ='ita'
     program_info: str = 'Aula IT'
-    audio_source: str  = 'file:./testdata/wave_particle_5min_it.wav'
+    audio_source: str  = 'file:./testdata/wave_particle_5min_it.lc3'
 
 
 class AuracastBigConfigPol(AuracastBigConfig):
@@ -105,11 +121,12 @@ class AuracastBigConfigPol(AuracastBigConfig):
     name: str  = 'Sala Wykładowa'
     language: str ='pol'
     program_info: str = 'Sala Wykładowa PL'
-    audio_source: str  = 'file:./testdata/wave_particle_5min_pl.wav'
+    audio_source: str  = 'file:./testdata/wave_particle_5min_pl.lc3'
 
 
 class AuracastConfigGroup(AuracastGlobalConfig):
     bigs: List[AuracastBigConfig] = [
         AuracastBigConfigDeu(),
     ]
-    analog_gain: int = 50  # ADC gain level for analog mode (10-60%)
+    analog_gain_db_left: float = 0.0  # ADC gain level for analog mode left channel (-12 to 18 dB)
+    analog_gain_db_right: float = 0.0  # ADC gain level for analog mode right channel (-12 to 18 dB)

src/auracast/multicast.py

@@ -30,6 +30,7 @@ import time
 import threading
 
 import numpy as np  # for audio down-mix
+import samplerate
 import os
 
 import lc3  # type: ignore  # pylint: disable=E0401
@@ -48,6 +49,7 @@ import bumble.transport
 import bumble.utils
 from bumble.device import Host, AdvertisingChannelMap
 from bumble.audio import io as audio_io
+from bumble.vendor.zephyr.hci import HCI_Write_Tx_Power_Level_Command
 
 from auracast import auracast_config
 from auracast.utils.read_lc3_file import read_lc3_file
@@ -56,7 +58,7 @@ from auracast.utils.webrtc_audio_input import WebRTCAudioInput
 
 
 # Patch sounddevice.InputStream globally to use low-latency settings
-import sounddevice as sd
+import alsaaudio
 from collections import deque
 
 
@@ -139,96 +141,146 @@ class AlsaArecordAudioInput(audio_io.AudioInput):
         self._proc = None
 
 
-class ModSoundDeviceAudioInput(audio_io.SoundDeviceAudioInput):
+class PyAlsaAudioInput(audio_io.ThreadedAudioInput):
-    """Patched SoundDeviceAudioInput with low-latency capture and adaptive resampling."""
+    """PyALSA audio input with non-blocking reads - supports mono/stereo."""
 
-    def _open(self):
+    def __init__(self, device, pcm_format: audio_io.PcmFormat):
-        """Create RawInputStream with low-latency parameters and initialize ring buffer."""
+        super().__init__()
-        dev_info = sd.query_devices(self._device)
+        logging.info("PyALSA: device = %s", device)
-        hostapis = sd.query_hostapis()
+        self._device = str(device) if not isinstance(device, str) else device
-        api_index = dev_info.get('hostapi')
+        if self._device.isdigit():
-        api_name = hostapis[api_index]['name'] if isinstance(api_index, int) and 0 <= api_index < len(hostapis) else 'unknown'
+            self._device = 'default' if self._device == '0' else f'hw:{self._device}'
-        pa_ver = sd.get_portaudio_version()
+        self._pcm_format = pcm_format
+        self._pcm = None
+        self._actual_channels = None
+        self._periodsize = None
+        self._hw_channels = None
+        self._first_read = True
+        self._resampler = None
+        self._resampler_buffer = np.empty(0, dtype=np.float32)
 
-        logging.info(
+    def _open(self) -> audio_io.PcmFormat:
-            "SoundDevice backend=%s device='%s' (id=%s) ch=%s default_low_input_latency=%.4f default_high_input_latency=%.4f portaudio=%s",
+        ALSA_PERIODSIZE = 240
-            api_name,
+        ALSA_PERIODS = 4
-            dev_info.get('name'),
+        ALSA_MODE = alsaaudio.PCM_NONBLOCK
-            self._device,
+        
-            dev_info.get('max_input_channels'),
+        requested_rate = int(self._pcm_format.sample_rate)
-            float(dev_info.get('default_low_input_latency') or 0.0),
+        requested_channels = int(self._pcm_format.channels)
-            float(dev_info.get('default_high_input_latency') or 0.0),
+        self._periodsize = ALSA_PERIODSIZE
-            pa_ver[1] if isinstance(pa_ver, tuple) and len(pa_ver) >= 2 else pa_ver,
+        
-        )
+        self._pcm = alsaaudio.PCM(
-        # Create RawInputStream with injected low-latency parameters
+            type=alsaaudio.PCM_CAPTURE,
-        # Target ~2 ms blocksize (48 kHz -> 96 frames). For other rates, keep ~2 ms.
+            mode=ALSA_MODE,
-        _sr = int(self._pcm_format.sample_rate)
-
-        self.counter=0
-        self.max_avail=0
-        self.logfile_name="available_samples.txt"
-        self.blocksize = 120
-
-        if os.path.exists(self.logfile_name):
-            os.remove(self.logfile_name)
-
-        self._stream = sd.RawInputStream(
-            samplerate=self._pcm_format.sample_rate,
             device=self._device,
-            channels=self._pcm_format.channels,
+            periods=ALSA_PERIODS,
-            dtype='int16',
-            blocksize=self.blocksize,
-            latency=0.004,
         )
-        self._stream.start()
+        
+        self._pcm.setchannels(requested_channels)
+        self._pcm.setformat(alsaaudio.PCM_FORMAT_S16_LE)
+        actual_rate = self._pcm.setrate(requested_rate)
+        self._pcm.setperiodsize(ALSA_PERIODSIZE)
+        
+        logging.info("PyALSA: device=%s rate=%d ch=%d periodsize=%d (%.1fms) periods=%d mode=%s", 
+                     self._device, actual_rate, requested_channels, ALSA_PERIODSIZE, 
+                     (ALSA_PERIODSIZE / actual_rate) * 1000, ALSA_PERIODS, ALSA_MODE)
+        
+        if actual_rate != requested_rate:
+            logging.warning("PyALSA: Sample rate mismatch! requested=%d actual=%d", requested_rate, actual_rate)
+        
+        self._actual_channels = requested_channels
+        self._resampler = samplerate.Resampler('sinc_fastest', channels=requested_channels)
+        self._resampler_buffer = np.empty(0, dtype=np.float32)
 
+        self._bang_bang = 0
+        
         return audio_io.PcmFormat(
             audio_io.PcmFormat.Endianness.LITTLE,
             audio_io.PcmFormat.SampleType.INT16,
-            self._pcm_format.sample_rate,
+            actual_rate,
-            1,
+            requested_channels,
         )
 
     def _read(self, frame_size: int) -> bytes:
-        """Read PCM samples from the stream."""
+        try:
+            avail = self._pcm.avail()
+            logging.debug("PyALSA: avail before read: %d", avail)
+            length, data = self._pcm.read_sw(frame_size + self._bang_bang)
+            avail = self._pcm.avail()
+            SETPOINT = 120 
+            TOLERANCE = 80 
+            if avail < SETPOINT - TOLERANCE:
+                self._bang_bang = -1 
+            elif avail > SETPOINT + TOLERANCE:
+                self._bang_bang = 1
+            else:
+                self._bang_bang = 0
+                
+                
+            logging.debug("PyALSA: read length=%d, data length=%d, avail=%d, bang_bang=%d", length, len(data), avail, self._bang_bang)
 
-        #if self.counter % 50 == 0:
+            if length > 0:
-        frame_size = frame_size + 1 # consume samples a little faster to avoid latency akkumulation
+                if self._first_read:
+                    expected_mono = self._periodsize * 2
+                    expected_stereo = self._periodsize * 2 * 2
+                    # self._hw_channels = 2 if len(data) == expected_stereo else 1
+                    self._hw_channels = self._actual_channels
+                    logging.info("PyALSA first read: bytes=%d detected_hw_channels=%d requested_channels=%d", 
+                                len(data), self._hw_channels, self._actual_channels)
+                    self._first_read = False
+                
+                if self._hw_channels == 2 and self._actual_channels == 1:
+                    pcm_stereo = np.frombuffer(data, dtype=np.int16)
+                    pcm_mono = pcm_stereo[::2]
+                    data = pcm_mono.tobytes()
+                
+                actual_samples = len(data) // (2 * self._actual_channels)
+                ratio = frame_size / actual_samples
+                pcm_f32 = np.frombuffer(data, dtype=np.int16).astype(np.float32) / 32768.0
+                if self._actual_channels > 1:
+                    pcm_f32 = pcm_f32.reshape(-1, self._actual_channels)
+                resampled = self._resampler.process(pcm_f32, ratio, end_of_input=False)
+                if self._actual_channels > 1:
+                    resampled = resampled.reshape(-1)
+                self._resampler_buffer = np.concatenate([self._resampler_buffer, resampled])
+            else:
+                logging.warning("PyALSA: No data read from ALSA")
+                self._resampler_buffer = np.concatenate([
+                    self._resampler_buffer,
+                    np.zeros(frame_size * self._actual_channels, dtype=np.float32),
+                ])
+        except alsaaudio.ALSAAudioError as e:
+            logging.error("PyALSA: ALSA read error: %s", e)
+            self._resampler_buffer = np.concatenate([
+                self._resampler_buffer,
+                np.zeros(frame_size * self._actual_channels, dtype=np.float32),
+            ])
+        except Exception as e:
+            logging.error("PyALSA: Unexpected error in _read: %s", e, exc_info=True)
+            self._resampler_buffer = np.concatenate([
+                self._resampler_buffer,
+                np.zeros(frame_size * self._actual_channels, dtype=np.float32),
+            ])
 
-        pcm_buffer, overflowed = self._stream.read(frame_size)
+        needed = frame_size * self._actual_channels
-        if overflowed:
+        if len(self._resampler_buffer) < needed:
-            logging.warning("SoundDeviceAudioInput: overflowed")
+            pad = np.zeros(needed - len(self._resampler_buffer), dtype=np.float32)
+            self._resampler_buffer = np.concatenate([self._resampler_buffer, pad])
+            logging.debug("PyALSA: padded buffer with %d samples", needed - len(self._resampler_buffer))
 
-        n_available = self._stream.read_available
+        output = self._resampler_buffer[:needed]
+        self._resampler_buffer = self._resampler_buffer[needed:]
 
-        # adapt = n_available > 20
+        logging.debug("PyALSA: resampler_buffer remaining=%d", len(self._resampler_buffer))
-        # if adapt:
+        return np.clip(output * 32767.0, -32768, 32767).astype(np.int16).tobytes()
-        #     pcm_extra, overflowed = self._stream.read(3)
-        #     logging.info('consuming extra samples, available was %d', n_available)
-        #     if overflowed:
-        #         logging.warning("SoundDeviceAudioInput: overflowed")
-            
-        #     out = bytes(pcm_buffer) +  bytes(pcm_extra)
-        # else:
-        out = bytes(pcm_buffer)     
 
-        self.max_avail = max(self.max_avail, n_available)
+  
 
-        #Diagnostics 
+    def _close(self) -> None:
-        #with open(self.logfile_name, "a", encoding="utf-8") as f:
+        if self._pcm:
-        #    f.write(f"{n_available}, {adapt}, {round(self._runavg, 2)}, {overflowed}\n")
+            self._pcm.close()
+            self._pcm = None
 
-        if self.counter % 500 == 0:
+audio_io.SoundDeviceAudioInput = PyAlsaAudioInput
-            logging.info(
-                "read available=%d, max=%d, latency:%d", 
-                n_available, self.max_avail, self._stream.latency
-            )
-            self.max_avail = 0
-
-        self.counter += 1
-        return out
-
-audio_io.SoundDeviceAudioInput = ModSoundDeviceAudioInput
 
 # modified from bumble
 class ModWaveAudioInput(audio_io.ThreadedAudioInput):
@@ -411,21 +463,6 @@ async def init_broadcast(
             ],
         )
         logger.info('Setup Advertising')
-        advertising_manufacturer_data = (
-        b''
-        if global_config.manufacturer_data == (None, None)
-        else bytes(
-            core.AdvertisingData(
-                [
-                    (
-                        core.AdvertisingData.MANUFACTURER_SPECIFIC_DATA,
-                        struct.pack('<H', global_config.manufacturer_data[0])
-                        + global_config.manufacturer_data[1],
-                    )
-                ]
-            )
-        )
-    )
         bigs[f'big{i}']['broadcast_audio_announcement'] = bap.BroadcastAudioAnnouncement(conf.id)
 
         # Build advertising data types list
@@ -468,13 +505,22 @@ async def init_broadcast(
                 advertising_sid=i,
                 primary_advertising_phy=hci.Phy.LE_1M, # 2m phy config throws error - because for primary advertising channels, 1mbit is only supported
                 secondary_advertising_phy=hci.Phy.LE_1M, # this is the secondary advertising beeing send on non advertising channels (extendend advertising)
-                #advertising_tx_power= # tx power in dbm (max 20)
+                # Pass NO_PREFERENCE (0x7F) here for two reasons:
+                # 1. The Nordic SoftDevice Controller ignores this field for
+                #    advertising sets and always returns the compile-time
+                #    CONFIG_BT_CTLR_TX_PWR_* value. The real TX power is
+                #    applied via the Zephyr VS Write_Tx_Power_Level command
+                #    issued right after create_advertising_set() returns.
+                # 2. Bumble's HCI metadata declares this field as 1-byte
+                #    *unsigned* (a bumble bug — the BT spec defines it as
+                #    signed int8), so negative values would raise
+                #    "bytes must be in range(0, 256)" at serialization.
+                advertising_tx_power=hci.HCI_LE_Set_Extended_Advertising_Parameters_Command.TX_POWER_NO_PREFERENCE,
                 #secondary_advertising_max_skip=10,
             ),
             advertising_data=(
                 bigs[f'big{i}']['broadcast_audio_announcement'].get_advertising_data()
                 + bytes(core.AdvertisingData(advertising_data_types))
-                + advertising_manufacturer_data
             ),
             periodic_advertising_parameters=bumble.device.PeriodicAdvertisingParameters(
                 periodic_advertising_interval_min=80,
@@ -485,6 +531,48 @@ async def init_broadcast(
             auto_start=True,
         )
         bigs[f'big{i}']['advertising_set'] = advertising_set
+        # NOTE: selected_tx_power below reflects the SDC's compile-time max
+        # (LE_Set_Ext_Adv_Params was sent with NO_PREFERENCE). The actual
+        # transmit power is set by the VS Write_Tx_Power_Level call below.
+        logging.debug(
+            'LE_Set_Ext_Adv_Params reports controller fallback TX power: %+d dBm (handle=%d)',
+            getattr(advertising_set, 'selected_tx_power', 0),
+            i,
+        )
+
+        # The Nordic SoftDevice Controller does not honor the per-set
+        # advertising_tx_power passed in HCI_LE_Set_Extended_Advertising_Parameters
+        # (it returns the compile-time CONFIG_BT_CTLR_TX_PWR_* value regardless).
+        # Apply the requested level via the Zephyr Vendor-Specific HCI command
+        # Write_Tx_Power_Level (opcode 0xFC0E), which the SDC honors per
+        # advertising handle. The SDC clamps the value to the nearest supported
+        # hardware step (max bounded by CONFIG_BT_CTLR_TX_PWR_PLUS_8).
+        try:
+            adv_handle = getattr(advertising_set, 'advertising_handle', i)
+            response = await device.send_command(
+                HCI_Write_Tx_Power_Level_Command(
+                    handle_type=HCI_Write_Tx_Power_Level_Command.TX_POWER_HANDLE_TYPE_ADV,
+                    connection_handle=adv_handle,
+                    tx_power_level=global_config.advertising_tx_power,
+                )
+            )
+            rp = getattr(response, 'return_parameters', None)
+            status = getattr(rp, 'status', 0xFF) if rp is not None else 0xFF
+            selected = getattr(rp, 'selected_tx_power_level', None) if rp is not None else None
+            if status == 0 and selected is not None:
+                logging.info(
+                    'Advertising TX power (VS Write_Tx_Power_Level): requested=%+d dBm, controller selected=%+d dBm (handle=%d)',
+                    global_config.advertising_tx_power,
+                    selected,
+                    adv_handle,
+                )
+            else:
+                logging.warning(
+                    'VS Write_Tx_Power_Level failed: status=0x%02X handle=%d requested=%+d dBm',
+                    status, adv_handle, global_config.advertising_tx_power,
+                )
+        except Exception as e:
+            logging.warning('VS Write_Tx_Power_Level not supported by controller: %s', e)
 
         logging.info('Start Periodic Advertising')
         await advertising_set.start_periodic()
@@ -538,7 +626,7 @@ async def init_broadcast(
 
     def on_flow():
         data_packet_queue = iso_queue.data_packet_queue
-        print(
+        logging.info(
             f'\rPACKETS: pending={data_packet_queue.pending}, '
             f'queued={data_packet_queue.queued}, '
             f'completed={data_packet_queue.completed}',
@@ -551,6 +639,29 @@ async def init_broadcast(
     return bigs
 
 
+def _lc3_file_byte_gen(filename: str, loop: bool = False):
+    """Stream LC3 frames from disk as individual bytes, with optional looping.
+
+    Yields one byte (int) at a time so it is compatible with the existing
+    ``bytes(itertools.islice(gen, bytes_per_frame))`` consumer without loading
+    the whole file into memory.
+    """
+    while True:
+        with open(filename, 'rb') as f:
+            f.read(18)  # skip 18-byte LC3 header
+            while True:
+                size_b = f.read(2)
+                if len(size_b) < 2:
+                    break
+                frame_size = struct.unpack('=H', size_b)[0]
+                frame = f.read(frame_size)
+                if len(frame) < frame_size:
+                    break
+                yield from frame
+        if not loop:
+            return
+
+
 class Streamer():
     """
     Streamer class that supports multiple input formats. See bumble for streaming from wav or device
@@ -706,13 +817,7 @@ class Streamer():
                 big['precoded'] = True
                 big['lc3_bytes_per_frame'] = global_config.octets_per_frame
                 filename = big_config[i].audio_source.replace('file:', '')
-
+                big['lc3_frames'] = _lc3_file_byte_gen(filename, loop=big_config[i].loop)
-                lc3_bytes = read_lc3_file(filename)
-                lc3_frames = iter(lc3_bytes)
-
-                if big_config[i].loop:
-                    lc3_frames = itertools.cycle(lc3_frames)
-                big['lc3_frames'] = lc3_frames
 
             # use wav files and code them entirely before streaming
             elif big_config[i].precode_wav and big_config[i].audio_source.endswith('.wav'):
@@ -760,7 +865,11 @@ class Streamer():
                     if input_format == 'auto':
                         raise ValueError('input format details required for alsa input')
                     pcm = audio_io.PcmFormat.from_str(input_format)
-                    audio_input = AlsaArecordAudioInput(audio_source[5:], pcm)
+                    device_name = audio_source[5:]
+                    if device_name.startswith('dante_'):
+                        audio_input = PyAlsaAudioInput(device_name, pcm)
+                    else:
+                        audio_input = AlsaArecordAudioInput(device_name, pcm)
                 else:
                     audio_input = await audio_io.create_audio_input(audio_source, input_format)
                 # Store early so stop_streaming can close even if open() fails
@@ -811,13 +920,6 @@ class Streamer():
                 big['encoder'] = encoders[0]
                 big['precoded'] = False
 
-            # Pre-compute software gain multiplier from dB config (0 dB = 1.0 = no change)
-            gain_db = getattr(big_config[i], 'input_gain_db', 0.0)
-            gain_db = max(0.0, min(20.0, float(gain_db)))
-            big['_gain_linear'] = 10.0 ** (gain_db / 20.0) if gain_db > 0 else 0.0
-            if big['_gain_linear'] > 0.0:
-                logging.info("Software gain for BIG %d: +%.1f dB (linear %.3f)", i, gain_db, big['_gain_linear'])
-
         logging.info("Streaming audio...")
         bigs = self.bigs
         self.is_streaming = True
@@ -836,6 +938,9 @@ class Streamer():
                     if lc3_frame == b'':  # Not all streams may stop at the same time
                         stream_finished[i] = True
                         continue
+
+                    for q_idx in range(big.get('num_bis', 1)):
+                        await big['iso_queues'][q_idx].write(lc3_frame)
                 else:  # code lc3 on the fly with perf counters
                     # Ensure frames generator exists (so we can aclose() on stop)
                     frames_gen = big.get('frames_gen')
@@ -865,14 +970,6 @@ class Streamer():
                         stream_finished[i] = True
                         continue
 
-                    # Apply software gain boost if configured (> 0 dB)
-                    gain_lin = big.get('_gain_linear', 0.0)
-                    if gain_lin > 0.0:
-                        pcm_arr = np.frombuffer(pcm_frame, dtype=np.int16).astype(np.float32)
-                        pcm_arr *= gain_lin
-                        np.clip(pcm_arr, -32768, 32767, out=pcm_arr)
-                        pcm_frame = pcm_arr.astype(np.int16).tobytes()
-
                     # Compute RMS audio level (normalized 0.0-1.0) for level monitoring
                     pcm_samples = np.frombuffer(pcm_frame, dtype=np.int16).astype(np.float32)
                     rms = np.sqrt(np.mean(pcm_samples ** 2)) / 32768.0 if len(pcm_samples) > 0 else 0.0

src/auracast/multicast_control.py

@@ -143,6 +143,10 @@ async def main():
         level=os.environ.get('LOG_LEVEL', logging.DEBUG),
         format='%(module)s.py:%(lineno)d %(levelname)s: %(message)s'
     )
+    
+    # Enable debug logging for bumble
+    # logging.getLogger('bumble').setLevel(logging.DEBUG)
+    
     os.chdir(os.path.dirname(__file__))
 
     global_conf = auracast_config.AuracastGlobalConfig(

src/auracast/server/multicast_server.py

@@ -3,12 +3,14 @@ TODO: in the future the multicaster objects should run in their own threads or e
 
 """
 import os
+import re
 import logging as log
 import json
 from datetime import datetime
 import asyncio
 import random
 import subprocess
+import threading
 from dotenv import load_dotenv
 
 from fastapi import FastAPI, HTTPException
@@ -26,6 +28,57 @@ from auracast.utils.sounddevice_utils import (
 )
 
 load_dotenv()
+
+# Blue LED on GPIO pin 12 (BCM) – turns on while transmitting
+LED_PIN = 12
+try:
+    import RPi.GPIO as _GPIO
+    _GPIO.setmode(_GPIO.BCM)
+    _GPIO.setup(LED_PIN, _GPIO.OUT)
+    _GPIO_AVAILABLE = True
+except Exception:
+    _GPIO_AVAILABLE = False
+    _GPIO = None  # type: ignore
+
+_LED_ENABLED: bool = True  # toggled via /set_led_enabled
+_LED_SETTINGS_FILE = os.path.join(os.path.dirname(__file__), 'led_settings.json')
+
+def _load_led_settings() -> None:
+    global _LED_ENABLED
+    try:
+        if os.path.exists(_LED_SETTINGS_FILE):
+            with open(_LED_SETTINGS_FILE, 'r', encoding='utf-8') as f:
+                data = json.load(f)
+            _LED_ENABLED = bool(data.get('led_enabled', True))
+    except Exception:
+        _LED_ENABLED = True
+
+def _save_led_settings() -> None:
+    try:
+        os.makedirs(os.path.dirname(_LED_SETTINGS_FILE), exist_ok=True)
+        with open(_LED_SETTINGS_FILE, 'w', encoding='utf-8') as f:
+            json.dump({'led_enabled': _LED_ENABLED}, f)
+    except Exception:
+        pass
+
+def _led_on():
+    if _GPIO_AVAILABLE and _LED_ENABLED:
+        try:
+            _GPIO.output(LED_PIN, _GPIO.LOW)
+        except Exception:
+            pass
+
+def _led_off():
+    if _GPIO_AVAILABLE:
+        try:
+            _GPIO.output(LED_PIN, _GPIO.HIGH)
+        except Exception:
+            pass
+
+
+# Configure bumble debug logging
+# log.getLogger('bumble').setLevel(log.DEBUG)
+
 # make sure pipewire sets latency
 # Primary and secondary persisted settings files
 STREAM_SETTINGS_FILE1 = os.path.join(os.path.dirname(__file__), 'stream_settings.json')
@@ -133,6 +186,10 @@ def save_settings(persisted: dict, secondary: bool = False) -> None:
 def gen_random_add() -> str:
     return ':'.join(['%02X' % random.randint(0, 255) for _ in range(6)])
 
+def gen_random_broadcast_id() -> int:
+    """Generate a random 24-bit Broadcast ID (1..0xFFFFFF)."""
+    return random.randint(1, 0xFFFFFF)
+
 app = FastAPI()
 
 # Allow CORS for frontend on localhost
@@ -152,6 +209,28 @@ multicaster1: multicast_control.Multicaster | None = None
 multicaster2: multicast_control.Multicaster | None = None
 _stream_lock = asyncio.Lock()  # serialize initialize/stop_audio on API side
 
+# BLE / audio event loop – set in __main__ before uvicorn starts.
+# All coroutines that touch Bumble objects or the audio pipeline MUST run
+# on this loop.  HTTP handlers call _on_ble_loop() to cross into it.
+_ble_loop: asyncio.AbstractEventLoop | None = None
+
+
+async def _on_ble_loop(coro):
+    """Submit *coro* to the BLE event loop and await the result.
+
+    Called from uvicorn's event loop.  Bridges HTTP handler coroutines into
+    the isolated BLE loop so that serial I/O (serial_asyncio / HCI) and the
+    audio pipeline are never preempted by HTTP accept/read/write callbacks.
+
+    asyncio.run_coroutine_threadsafe() schedules the coroutine on _ble_loop
+    (thread-safe), returning a concurrent.futures.Future.
+    asyncio.wrap_future() adapts that into an asyncio.Future so the caller
+    can simply `await` it inside uvicorn's loop.
+    """
+    assert _ble_loop is not None, "BLE loop not yet initialised"
+    future = asyncio.run_coroutine_threadsafe(coro, _ble_loop)
+    return await asyncio.wrap_future(future)
+
 
 async def _init_i2c_on_startup() -> None:
     # Ensure i2c-dev kernel module is loaded (required for /dev/i2c-* access)
@@ -238,16 +317,18 @@ async def _init_i2c_on_startup() -> None:
             log.warning("Exception running i2cget (%s): %s", " ".join(read_cmd), e, exc_info=True)
 
 
-async def _set_adc_level(gain_percent: int = 50) -> None:
+async def _set_adc_level(gain_db_left: float = 0.0, gain_db_right: float = 0.0) -> None:
-    """Set ADC mixer level.
+    """Set ADC mixer gain in dB for left and right channels independently.
 
-    Runs: amixer -c 1 set 'ADC' x%
+    Runs: amixer -c 2 sset ADC {gain_db_left}dB,{gain_db_right}dB
     
     Args:
-        gain_percent: Gain level 10-60, default 50 (above 60% causes clipping/silence)
+        gain_db_left: Left channel gain in dB (-12 to 18), default 0
+        gain_db_right: Right channel gain in dB (-12 to 18), default 0
     """
-    gain_percent = max(10, min(60, gain_percent))
+    gain_db_left = max(-12.0, min(18.0, gain_db_left))
-    cmd = ["amixer", "-c", "1", "set", "ADC", f"{gain_percent}%"]
+    gain_db_right = max(-12.0, min(18.0, gain_db_right))
+    cmd = ["amixer", "-c", "2", "sset", "ADC", "--", f"{int(gain_db_left)}dB,{int(gain_db_right)}dB"]
     try:
         proc = await asyncio.create_subprocess_exec(
             *cmd,
@@ -256,15 +337,46 @@ async def _set_adc_level(gain_percent: int = 50) -> None:
         )
         stdout, stderr = await proc.communicate()
         if proc.returncode != 0:
-            log.warning(
+            log.error(
                 "amixer ADC level command failed (rc=%s): %s",
                 proc.returncode,
                 (stderr or b"" ).decode(errors="ignore").strip(),
             )
         else:
             log.info("amixer ADC level set successfully: %s", (stdout or b"" ).decode(errors="ignore").strip())
+            read_proc = await asyncio.create_subprocess_exec(
+                "amixer", "-c", "2", "sget", "ADC",
+                stdout=asyncio.subprocess.PIPE,
+                stderr=asyncio.subprocess.PIPE,
+            )
+            read_stdout, read_stderr = await read_proc.communicate()
+            if read_proc.returncode != 0:
+                log.error(
+                    "amixer ADC sget failed (rc=%s): %s",
+                    read_proc.returncode,
+                    (read_stderr or b"").decode(errors="ignore").strip(),
+                )
+            else:
+                sget_output = (read_stdout or b"").decode(errors="ignore")
+                actual = {}
+                for line in sget_output.splitlines():
+                    for ch_key, ch_name in (("left", "Front Left"), ("right", "Front Right")):
+                        if ch_name in line:
+                            m = re.search(r'\[(-?\d+(?:\.\d+)?)dB\]', line)
+                            if m:
+                                actual[ch_key] = round(float(m.group(1)))
+                expected_left = int(gain_db_left)
+                expected_right = int(gain_db_right)
+                if actual.get("left") != expected_left or actual.get("right") != expected_right:
+                    mismatch = (
+                        f"ADC level mismatch after set: expected L={expected_left}dB R={expected_right}dB, "
+                        f"got L={actual.get('left')}dB R={actual.get('right')}dB"
+                    )
+                    log.error(mismatch)
+                else:
+                    log.info("ADC level set successfully: L=%sdB R=%sdB", expected_left, expected_right)
     except Exception as e:
-        log.warning("Exception running amixer ADC level command: %s", e, exc_info=True)
+        log.error("Exception running amixer ADC level command: %s", e, exc_info=True)
 
 
 async def _stop_all() -> bool:
@@ -284,6 +396,7 @@ async def _stop_all() -> bool:
             was_running = True
         finally:
             multicaster2 = None
+    _led_off()
     return was_running
 
 async def _status_primary() -> dict:
@@ -332,6 +445,11 @@ async def init_radio(transport: str, conf: auracast_config.AuracastConfigGroup,
         first_source = conf.bigs[0].audio_source if conf.bigs else ''
         input_device_name = None
         audio_mode_persist = 'Demo'
+        # Capture original per-BIG device names before transformation
+        original_input_devices = [
+            big.audio_source.split(':', 1)[1] if (isinstance(big.audio_source, str) and big.audio_source.startswith('device:')) else None
+            for big in conf.bigs
+        ]
         if any(isinstance(b.audio_source, str) and b.audio_source.startswith('device:') for b in conf.bigs):
             if isinstance(first_source, str) and first_source.startswith('device:'):
                 input_device_name = first_source.split(':', 1)[1] if ':' in first_source else None
@@ -343,8 +461,9 @@ async def init_radio(transport: str, conf: auracast_config.AuracastConfigGroup,
             if input_device_name in ('ch1', 'ch2'):
                 audio_mode_persist = 'Analog'
                 # Set ADC gain level for analog mode
-                analog_gain = getattr(conf, 'analog_gain', 50)
+                analog_gain_db_left = getattr(conf, 'analog_gain_db_left', 0.0)
-                await _set_adc_level(analog_gain)
+                analog_gain_db_right = getattr(conf, 'analog_gain_db_right', 0.0)
+                await _set_adc_level(analog_gain_db_left, analog_gain_db_right)
             elif input_device_name in dante_channels:
                 audio_mode_persist = 'Network - Dante'
             else:
@@ -387,18 +506,15 @@ async def init_radio(transport: str, conf: auracast_config.AuracastConfigGroup,
                     if is_stereo and sel == 'ch1':
                         # Stereo mode: use ALSA directly to capture both channels from hardware
                         # ch1=left (channel 0), ch2=right (channel 1)
-                        big.audio_source = 'alsa:hw:CARD=i2s,DEV=0'
+                        big.audio_source = 'device:hw:2'
                         big.input_format = f"int16le,{hardware_capture_rate},2"
                         log.info("Configured analog stereo input: using ALSA hw:CARD=i2s,DEV=0 with ch1=left, ch2=right")
                     elif is_stereo and sel == 'ch2':
                         # Skip ch2 in stereo mode as it's already captured as part of stereo pair
                         continue
                     else:
-                        # Mono mode: individual channel capture
+                        # Mono mode: use dsnoop virtual device directly (ch1=left, ch2=right)
-                        device_index = resolve_input_device_index(sel)
+                        big.audio_source = f'device:{sel}'
-                        if device_index is None:
-                            raise HTTPException(status_code=400, detail=f"Audio device '{sel}' not found.")
-                        big.audio_source = f'device:{device_index}'
                         big.input_format = f"int16le,{hardware_capture_rate},1"
                     continue
 
@@ -454,10 +570,12 @@ async def init_radio(transport: str, conf: auracast_config.AuracastConfigGroup,
 
         conf.qos_config.max_transport_latency_ms = int(conf.qos_config.number_of_retransmissions) * 10 + 3
 
-        # Only generate a new random_address if the BIG is still at the model default.
+        # Generate fresh random_address and broadcast ID for any BIG still at model defaults.
         for big in conf.bigs:
             if not getattr(big, 'random_address', None) or big.random_address == DEFAULT_RANDOM_ADDRESS:
                 big.random_address = gen_random_add()
+            if big.id == DEFAULT_BIG_ID:
+                big.id = gen_random_broadcast_id()
 
         # Log the final, fully-updated configuration just before creating the Multicaster
         log.info('Final multicaster config (transport=%s):\n %s', transport, conf.model_dump_json(indent=2))
@@ -468,11 +586,19 @@ async def init_radio(transport: str, conf: auracast_config.AuracastConfigGroup,
         auto_started = False
         if any(isinstance(big.audio_source, str) and (big.audio_source.startswith("device:") or big.audio_source.startswith("alsa:") or big.audio_source.startswith("file:")) for big in conf.bigs):
             await mc.start_streaming()
+            _led_on()
             auto_started = True
 
         demo_count = sum(1 for big in conf.bigs if isinstance(big.audio_source, str) and big.audio_source.startswith('file:'))
         demo_rate = int(conf.auracast_sampling_rate_hz or 0)
         demo_type = None
+        demo_sources = [
+            str(b.audio_source)
+            for b in conf.bigs
+            if isinstance(b.audio_source, str) and b.audio_source.startswith('file:')
+        ]
+        is_demo_tone = bool(demo_sources) and all('test_tone_1k_' in src for src in demo_sources)
+        demo_content = '1 kHz test tone' if is_demo_tone else 'Program material'
         if demo_count > 0 and demo_rate > 0:
             if demo_rate in (48000, 24000, 16000):
                 demo_type = f"{demo_count} × {demo_rate//1000}kHz"
@@ -483,6 +609,7 @@ async def init_radio(transport: str, conf: auracast_config.AuracastConfigGroup,
             'languages': [big.language for big in conf.bigs],
             'audio_mode': audio_mode_persist,
             'input_device': input_device_name,
+            'input_devices': original_input_devices,
             'program_info': [getattr(big, 'program_info', None) for big in conf.bigs],
             'gain': [getattr(big, 'input_gain', 1.0) for big in conf.bigs],
             'auracast_sampling_rate_hz': conf.auracast_sampling_rate_hz,
@@ -492,15 +619,17 @@ async def init_radio(transport: str, conf: auracast_config.AuracastConfigGroup,
             'immediate_rendering': getattr(conf, 'immediate_rendering', False),
             'assisted_listening_stream': getattr(conf, 'assisted_listening_stream', False),
             'analog_stereo_mode': getattr(conf.bigs[0], 'analog_stereo_mode', False) if conf.bigs else False,
-            'analog_gain': getattr(conf, 'analog_gain', 50),
+            'analog_gain_db_left': getattr(conf, 'analog_gain_db_left', 0.0),
-            'software_boost_db': getattr(conf.bigs[0], 'input_gain_db', 0.0) if conf.bigs else 0.0,
+            'analog_gain_db_right': getattr(conf, 'analog_gain_db_right', 0.0),
+            'advertising_tx_power': getattr(conf, 'advertising_tx_power', 8),
             'stream_password': (conf.bigs[0].code if conf.bigs and getattr(conf.bigs[0], 'code', None) else None),
             'big_ids': [getattr(big, 'id', DEFAULT_BIG_ID) for big in conf.bigs],
             'big_random_addresses': [getattr(big, 'random_address', DEFAULT_RANDOM_ADDRESS) for big in conf.bigs],
             'demo_total_streams': demo_count,
             'demo_stream_type': demo_type,
+            'demo_content': demo_content,
             'is_streaming': auto_started,
-            'demo_sources': [str(b.audio_source) for b in conf.bigs if isinstance(b.audio_source, str) and b.audio_source.startswith('file:')],
+            'demo_sources': demo_sources,
         }
         return mc, persisted
     except HTTPException:
@@ -511,7 +640,10 @@ async def init_radio(transport: str, conf: auracast_config.AuracastConfigGroup,
 
 @app.post("/init")
 async def initialize(conf: auracast_config.AuracastConfigGroup):
-    """Initializes the primary broadcaster on the streamer thread."""
+    """Initializes the primary broadcaster on the BLE loop."""
+    return await _on_ble_loop(_initialize_impl(conf))
+
+async def _initialize_impl(conf: auracast_config.AuracastConfigGroup):
     async with _stream_lock:
         global multicaster1, global_config_group
         mc, persisted = await init_radio(TRANSPORT1, conf, multicaster1)
@@ -521,16 +653,33 @@ async def initialize(conf: auracast_config.AuracastConfigGroup):
 
 @app.post("/init2")
 async def initialize2(conf: auracast_config.AuracastConfigGroup):
-    """Initializes the secondary broadcaster on the streamer thread."""
+    """Initializes the secondary broadcaster on the BLE loop."""
+    return await _on_ble_loop(_initialize2_impl(conf))
+
+async def _initialize2_impl(conf: auracast_config.AuracastConfigGroup):
     async with _stream_lock:
         global multicaster2
         mc, persisted = await init_radio(TRANSPORT2, conf, multicaster2)
         multicaster2 = mc
         save_settings(persisted, secondary=True)
 
+@app.post("/set_led_enabled")
+async def set_led_enabled(body: dict):
+    """Enable or disable the blue status LED. Persisted across restarts."""
+    global _LED_ENABLED
+    _LED_ENABLED = bool(body.get("led_enabled", True))
+    _save_led_settings()
+    if not _LED_ENABLED:
+        _led_off()
+    return {"led_enabled": _LED_ENABLED}
+
 @app.post("/stop_audio")
 async def stop_audio():
-    """Stops streaming on both multicaster1 and multicaster2 (worker thread)."""
+    """Stops streaming on both multicasters via the BLE loop."""
+    return await _on_ble_loop(_stop_audio_impl())
+
+async def _stop_audio_impl():
+    """Runs on BLE loop: stops all streamers and persists is_streaming=False."""
     try:
         was_running = await _stop_all()
 
@@ -556,11 +705,33 @@ async def stop_audio():
         log.error("Exception in /stop_audio: %s", traceback.format_exc())
         raise HTTPException(status_code=500, detail=str(e))
 
+@app.post("/adc_gain")
+async def set_adc_gain(payload: dict):
+    """Set ADC gain in dB for left and right channels without restarting the stream.
+
+    Body: {"gain_db_left": float, "gain_db_right": float}
+    """
+    try:
+        gain_db_left = float(payload.get("gain_db_left", 0.0))
+        gain_db_right = float(payload.get("gain_db_right", 0.0))
+        await _set_adc_level(gain_db_left, gain_db_right)
+        # Persist the new values so they survive a restart
+        for load_fn, save_fn in [(load_stream_settings, save_stream_settings), (load_stream_settings2, save_stream_settings2)]:
+            s = load_fn() or {}
+            if s:
+                s['analog_gain_db_left'] = gain_db_left
+                s['analog_gain_db_right'] = gain_db_right
+                save_fn(s)
+        return {"status": "ok", "gain_db_left": gain_db_left, "gain_db_right": gain_db_right}
+    except Exception as e:
+        log.error("Exception in /adc_gain: %s", traceback.format_exc())
+        raise HTTPException(status_code=500, detail=str(e))
+
 @app.post("/stream_lc3")
 async def send_audio(audio_data: dict[str, str]):
-    """Sends a block of pre-coded LC3 audio via the worker."""
+    """Sends a block of pre-coded LC3 audio via the BLE loop."""
     try:
-        await _stream_lc3(audio_data, list(global_config_group.bigs))
+        await _on_ble_loop(_stream_lc3(audio_data, list(global_config_group.bigs)))
         return {"status": "audio_sent"}
     except Exception as e:
         raise HTTPException(status_code=500, detail=str(e))
@@ -591,6 +762,7 @@ async def get_status():
     secondary.update(secondary_persisted)
     status["secondary"] = secondary
     status["secondary_is_streaming"] = bool(secondary.get("is_streaming", False))
+    status["led_enabled"] = _LED_ENABLED
 
     return status
 
@@ -631,11 +803,12 @@ async def _autostart_from_settings():
         big_ids = settings.get('big_ids') or []
         big_addrs = settings.get('big_random_addresses') or []
         stream_password = settings.get('stream_password')
+        tx_power = int(settings.get('advertising_tx_power', 8))
         original_ts = settings.get('timestamp')
         previously_streaming = bool(settings.get('is_streaming'))
 
         log.info(
-            "[AUTOSTART][PRIMARY] loaded settings: previously_streaming=%s audio_mode=%s rate=%s octets=%s pres_delay=%s qos_preset=%s immediate_rendering=%s assisted_listening_stream=%s demo_sources=%s",
+            "[AUTOSTART][PRIMARY] loaded settings: previously_streaming=%s audio_mode=%s rate=%s octets=%s pres_delay=%s qos_preset=%s immediate_rendering=%s assisted_listening_stream=%s tx_power=%+d dBm demo_sources=%s",
             previously_streaming,
             audio_mode,
             rate,
@@ -644,6 +817,7 @@ async def _autostart_from_settings():
             saved_qos_preset,
             immediate_rendering,
             assisted_listening_stream,
+            tx_power,
             (settings.get('demo_sources') or []),
         )
 
@@ -693,6 +867,7 @@ async def _autostart_from_settings():
                 immediate_rendering=immediate_rendering,
                 assisted_listening_stream=assisted_listening_stream,
                 presentation_delay_us=pres_delay if pres_delay is not None else 40000,
+                advertising_tx_power=tx_power,
                 bigs=bigs,
             )
             # Set num_bis for stereo mode if needed
@@ -751,7 +926,6 @@ async def _autostart_from_settings():
                         iso_que_len=1,
                         sampling_frequency=rate,
                         octets_per_frame=octets,
-                        input_gain_db=float(settings.get('software_boost_db', 0)),
                     )
                 ]
                 conf = auracast_config.AuracastConfigGroup(
@@ -761,7 +935,9 @@ async def _autostart_from_settings():
                     immediate_rendering=immediate_rendering,
                     assisted_listening_stream=assisted_listening_stream,
                     presentation_delay_us=pres_delay if pres_delay is not None else 40000,
-                    analog_gain=settings.get('analog_gain', 50),
+                    analog_gain_db_left=settings.get('analog_gain_db_left', 0.0),
+                    analog_gain_db_right=settings.get('analog_gain_db_right', 0.0),
+                    advertising_tx_power=tx_power,
                     bigs=bigs,
                 )
                 # Set num_bis for stereo mode if needed
@@ -797,10 +973,11 @@ async def _autostart_from_settings():
         big_ids = settings.get('big_ids') or []
         big_addrs = settings.get('big_random_addresses') or []
         stream_password = settings.get('stream_password')
+        tx_power = int(settings.get('advertising_tx_power', 8))
         original_ts = settings.get('timestamp')
         previously_streaming = bool(settings.get('is_streaming'))
         log.info(
-            "[AUTOSTART][SECONDARY] loaded settings: previously_streaming=%s audio_mode=%s rate=%s octets=%s pres_delay=%s qos_preset=%s immediate_rendering=%s assisted_listening_stream=%s demo_sources=%s",
+            "[AUTOSTART][SECONDARY] loaded settings: previously_streaming=%s audio_mode=%s rate=%s octets=%s pres_delay=%s qos_preset=%s immediate_rendering=%s assisted_listening_stream=%s tx_power=%+d dBm demo_sources=%s",
             previously_streaming,
             audio_mode,
             rate,
@@ -809,6 +986,7 @@ async def _autostart_from_settings():
             saved_qos_preset,
             immediate_rendering,
             assisted_listening_stream,
+            tx_power,
             (settings.get('demo_sources') or []),
         )
         if not previously_streaming:
@@ -848,6 +1026,7 @@ async def _autostart_from_settings():
                 immediate_rendering=immediate_rendering,
                 assisted_listening_stream=assisted_listening_stream,
                 presentation_delay_us=pres_delay if pres_delay is not None else 40000,
+                advertising_tx_power=tx_power,
                 bigs=bigs,
             )
             conf.qos_config = QOS_PRESET_MAP.get(saved_qos_preset, QOS_PRESET_MAP["Fast"])
@@ -906,7 +1085,6 @@ async def _autostart_from_settings():
                         iso_que_len=1,
                         sampling_frequency=rate,
                         octets_per_frame=octets,
-                        input_gain_db=float(settings.get('software_boost_db', 0)),
                     )
                 ]
                 conf = auracast_config.AuracastConfigGroup(
@@ -916,7 +1094,9 @@ async def _autostart_from_settings():
                     immediate_rendering=immediate_rendering,
                     assisted_listening_stream=assisted_listening_stream,
                     presentation_delay_us=pres_delay if pres_delay is not None else 40000,
-                    analog_gain=settings.get('analog_gain', 50),
+                    analog_gain_db_left=settings.get('analog_gain_db_left', 0.0),
+                    analog_gain_db_right=settings.get('analog_gain_db_right', 0.0),
+                    advertising_tx_power=tx_power,
                     bigs=bigs,
                 )
                 conf.qos_config = QOS_PRESET_MAP.get(saved_qos_preset, QOS_PRESET_MAP["Fast"])
@@ -934,13 +1114,27 @@ async def _autostart_from_settings():
     await do_primary()
     await do_secondary()
 
+async def _ble_startup():
+    """I2C init, ADC level reset, and autostart task scheduling on the BLE loop.
+
+    Bridged from _startup_autostart_event() so that these async subprocess
+    calls and the long-lived autostart coroutine all run on _ble_loop, never
+    on uvicorn's HTTP loop.
+    """
+    await _init_i2c_on_startup()
+    await _set_adc_level(0.0, 0.0)
+    log.info("[STARTUP] Scheduling autostart task on BLE loop")
+    asyncio.create_task(_autostart_from_settings())
+
+
 @app.on_event("startup")  
 async def _startup_autostart_event():
     # Spawn the autostart task without blocking startup
     log.info("[STARTUP] Auracast multicast server startup: initializing settings cache, I2C, and PipeWire cache")
+    _led_off()
     
     # Run install_asoundconf.sh script
-    script_path = os.path.join(os.path.dirname(__file__), '..', 'misc', 'install_asoundconf.sh')
+    script_path = os.path.join(os.path.dirname(__file__), '..', '..', 'misc', 'install_asoundconf.sh')
     try:
         log.info("[STARTUP] Running install_asoundconf.sh script")
         result = subprocess.run(['bash', script_path], capture_output=True, text=True, check=True)
@@ -951,13 +1145,13 @@ async def _startup_autostart_event():
         log.error(f"[STARTUP] Error running install_asoundconf.sh: {str(e)}")
     
     # Hydrate settings cache once to avoid disk I/O during /status
+    _load_led_settings()
     _init_settings_cache_from_disk()
-    await _init_i2c_on_startup()
-    # Ensure ADC mixer level is set at startup (default 50%)
-    await _set_adc_level(50)
     refresh_pw_cache()
-    log.info("[STARTUP] Scheduling autostart task")
+    # I2C init, ADC setup and the autostart task must run on the BLE loop so
-    asyncio.create_task(_autostart_from_settings())
+    # they share the same event loop as the Bumble HCI transport.
+    log.info("[STARTUP] Bridging I2C init and autostart to BLE loop")
+    asyncio.run_coroutine_threadsafe(_ble_startup(), _ble_loop)
 
 @app.get("/audio_inputs_pw_usb")
 async def audio_inputs_pw_usb():
@@ -1028,6 +1222,9 @@ async def refresh_audio_devices():
 @app.post("/shutdown")
 async def shutdown():
     """Stops broadcasting and releases all audio/Bluetooth resources."""
+    return await _on_ble_loop(_shutdown_impl())
+
+async def _shutdown_impl():
     try:
         await _stop_all()
         return {"status": "stopped"}
@@ -1040,6 +1237,9 @@ async def system_reboot():
 
     Requires the service user to have passwordless sudo permissions to run 'reboot'.
     """
+    return await _on_ble_loop(_system_reboot_impl())
+
+async def _system_reboot_impl():
     try:
         # Best-effort: stop any active streaming cleanly WITHOUT persisting state
         try:
@@ -1063,47 +1263,27 @@ async def system_reboot():
 
 @app.post("/restart_dep")
 async def restart_dep():
-    """Restart DEP by running dep.sh stop then dep.sh start in the dep directory.
+    """Restart DEP via systemctl restart dep.service.
     
-    Requires the service user to have passwordless sudo permissions to run dep.sh.
+    Requires the service user to have passwordless sudo permissions for systemctl.
     """
     try:
-        # Get the dep directory path (dep.sh is in dante_package subdirectory)
+        log.info("Restarting DEP via systemctl...")
-        dep_dir = os.path.join(os.path.dirname(__file__), '..', '..', 'dep', 'dante_package')
+        proc = await asyncio.create_subprocess_exec(
-        
+            "sudo", "systemctl", "restart", "dep.service",
-        # Run dep.sh stop first
-        log.info("Stopping DEP...")
-        stop_process = await asyncio.create_subprocess_exec(
-            "sudo", "bash", "dep.sh", "stop",
-            cwd=dep_dir,
             stdout=asyncio.subprocess.PIPE,
             stderr=asyncio.subprocess.PIPE
         )
-        stop_stdout, stop_stderr = await stop_process.communicate()
+        stdout, stderr = await proc.communicate()
-        
+
-        if stop_process.returncode != 0:
+        if proc.returncode == 0:
-            error_msg = stop_stderr.decode() if stop_stderr else "Unknown error"
-            log.error(f"Failed to stop DEP: {error_msg}")
-            raise HTTPException(status_code=500, detail=f"Failed to stop DEP: {error_msg}")
-        
-        # Run dep.sh start after stop succeeds
-        log.info("Starting DEP...")
-        start_process = await asyncio.create_subprocess_exec(
-            "sudo", "bash", "dep.sh", "start",
-            cwd=dep_dir,
-            stdout=asyncio.subprocess.PIPE,
-            stderr=asyncio.subprocess.PIPE
-        )
-        start_stdout, start_stderr = await start_process.communicate()
-        
-        if start_process.returncode == 0:
             log.info("DEP restarted successfully")
             return {"status": "success", "message": "DEP restarted successfully"}
         else:
-            error_msg = start_stderr.decode() if start_stderr else "Unknown error"
+            error_msg = stderr.decode() if stderr else "Unknown error"
-            log.error(f"Failed to start DEP: {error_msg}")
+            log.error(f"Failed to restart DEP: {error_msg}")
-            raise HTTPException(status_code=500, detail=f"Failed to start DEP: {error_msg}")
+            raise HTTPException(status_code=500, detail=f"Failed to restart DEP: {error_msg}")
-            
+
     except HTTPException:
         raise
     except Exception as e:
@@ -1196,6 +1376,9 @@ async def check_update():
 @app.post("/system_update")
 async def system_update():
     """Update application: git pull main branch (latest tag), poetry install, restart services."""
+    return await _on_ble_loop(_system_update_impl())
+
+async def _system_update_impl():
     try:
         # Best-effort: stop any active streaming cleanly
         try:
@@ -1245,26 +1428,12 @@ async def system_update():
             log.error("git checkout failed: %s", stderr.decode())
             raise HTTPException(status_code=500, detail=f"git checkout failed: {stderr.decode()}")
 
-        # 2. Run poetry install (use full path as poetry is in user's ~/.local/bin)
+        # 2. Hand off remaining work to the (now-updated) system_update.sh script
-        poetry_path = os.path.expanduser("~/.local/bin/poetry")
+        update_script = os.path.join(os.path.dirname(__file__), 'system_update.sh')
-        proc = await asyncio.create_subprocess_exec(
+        log.info("Handing off to system_update.sh...")
-            poetry_path, "install",
+        await asyncio.create_subprocess_exec(
-            cwd=project_root,
-            stdout=asyncio.subprocess.PIPE,
-            stderr=asyncio.subprocess.PIPE
-        )
-        stdout, stderr = await proc.communicate()
-        if proc.returncode != 0:
-            log.error("poetry install failed: %s", stderr.decode())
-            raise HTTPException(status_code=500, detail=f"poetry install failed: {stderr.decode()}")
-
-        # 3. Restart services via the update script
-        update_script = os.path.join(project_root, 'src', 'service', 'update_and_run_server_and_frontend.sh')
-        proc = await asyncio.create_subprocess_exec(
             "bash", update_script,
             cwd=project_root,
-            stdout=asyncio.subprocess.PIPE,
-            stderr=asyncio.subprocess.PIPE
         )
         # Don't wait for completion as we'll be restarted
         await asyncio.sleep(0.5)
@@ -1677,5 +1846,170 @@ if __name__ == '__main__':
         level=os.environ.get('LOG_LEVEL', log.INFO),
         format='%(module)s.py:%(lineno)d %(levelname)s: %(message)s'
     )
+
+    # ── GIL switch interval ─────────────────────────────────────────────────
+    # CPython releases the GIL every sys.getswitchinterval() seconds (default
+    # 5 ms).  The audio pipeline fires every 10 ms, so a 5 ms granularity
+    # means up to half a frame period can be wasted waiting for the GIL.
+    # Reducing to 1 ms gives the BLE thread much tighter access.
+    import sys
+    sys.setswitchinterval(0.001)
+    log.info("GIL switch interval set to 1 ms")
+
+    # ── BLE / audio event loop ──────────────────────────────────────────────
+    # Bumble (serial_asyncio / HCI) and the audio pipeline run exclusively on
+    # this loop.  Uvicorn's HTTP accept/read/write callbacks run on a separate
+    # asyncio loop in the main thread, so they can never stall BLE advertising
+    # or audio encoding.
+    #
+    # Route handlers that touch Bumble objects call _on_ble_loop(), which uses
+    # asyncio.run_coroutine_threadsafe() + asyncio.wrap_future() to submit the
+    # coroutine to _ble_loop and await the result back in uvicorn's loop.
+    # Hot-path read-only endpoints (/status, /audio_level*) access
+    # multicaster state directly – Python's GIL makes attribute reads safe.
+
+    def _pthread_sched_lib():
+        """Return a ctypes handle with correctly typed pthread scheduling symbols.
+
+        Uses RTLD_DEFAULT (ctypes.CDLL(None)) to resolve symbols from all
+        currently loaded shared libraries.  This handles both:
+          - glibc < 2.34: pthread_self/pthread_setschedparam live in libpthread.so.0
+          - glibc >= 2.34: pthreads merged into libc.so.6
+        using find_library("c") would miss libpthread on older glibc and cause
+        a NULL function pointer → SEGV when called.
+
+        Explicit restype/argtypes are mandatory: pthread_t is c_ulong (64-bit
+        on ARM64/x86-64) but ctypes defaults to c_int (32-bit), truncating
+        the thread handle and causing a SEGV inside pthread_setschedparam.
+        """
+        import ctypes
+
+        SCHED_FIFO  = 1
+        SCHED_OTHER = 0
+
+        class SchedParam(ctypes.Structure):
+            _fields_ = [("sched_priority", ctypes.c_int)]
+
+        lib = ctypes.CDLL(None, use_errno=True)  # RTLD_DEFAULT
+
+        lib.pthread_self.restype  = ctypes.c_ulong
+        lib.pthread_self.argtypes = []
+
+        lib.pthread_getschedparam.restype  = ctypes.c_int
+        lib.pthread_getschedparam.argtypes = [
+            ctypes.c_ulong,
+            ctypes.POINTER(ctypes.c_int),
+            ctypes.POINTER(SchedParam),
+        ]
+        lib.pthread_setschedparam.restype  = ctypes.c_int
+        lib.pthread_setschedparam.argtypes = [
+            ctypes.c_ulong,
+            ctypes.c_int,
+            ctypes.POINTER(SchedParam),
+        ]
+        return lib, SchedParam, SCHED_FIFO, SCHED_OTHER
+
+    def _configure_ble_thread_scheduling():
+        """Confirm or establish SCHED_FIFO for the BLE/audio thread.
+
+        When launched via the systemd unit (CPUSchedulingPolicy=fifo), new
+        threads inherit the process RT policy automatically – just log and
+        return.  When run directly (development), attempt to elevate to
+        SCHED_FIFO/30 (requires CAP_SYS_NICE), falling back gracefully.
+        """
+        import ctypes
+        try:
+            lib, SchedParam, SCHED_FIFO, _ = _pthread_sched_lib()
+            tid     = lib.pthread_self()
+            policy  = ctypes.c_int(-1)
+            param   = SchedParam(0)
+            lib.pthread_getschedparam(tid, ctypes.byref(policy), ctypes.byref(param))
+
+            if policy.value == SCHED_FIFO:
+                log.info("[BLE-LOOP] Already SCHED_FIFO priority=%d (inherited from systemd)",
+                         param.sched_priority)
+                return
+
+            param.sched_priority = 30
+            ret = lib.pthread_setschedparam(tid, SCHED_FIFO, ctypes.byref(param))
+            if ret == 0:
+                log.info("[BLE-LOOP] SCHED_FIFO priority=30 set")
+            else:
+                err = ctypes.get_errno()
+                log.warning("[BLE-LOOP] SCHED_FIFO failed (errno=%d: %s) – "
+                            "use systemd CPUSchedulingPolicy=fifo or grant CAP_SYS_NICE",
+                            err, os.strerror(err))
+                try:
+                    os.setpriority(os.PRIO_PROCESS, 0,
+                                   os.getpriority(os.PRIO_PROCESS, 0) - 5)
+                except PermissionError:
+                    pass
+        except Exception as exc:
+            log.warning("[BLE-LOOP] Scheduling setup error: %s", exc)
+
+    def _configure_http_thread_scheduling():
+        """Demote the HTTP (uvicorn) thread to SCHED_OTHER + nice=+10.
+
+        When systemd sets CPUSchedulingPolicy=fifo, every thread in the
+        process – including uvicorn's main loop – inherits SCHED_FIFO.
+        We demote the HTTP thread back to SCHED_OTHER so the BLE thread
+        always wins CPU arbitration when both are runnable.
+        Lowering scheduling policy never requires special privileges.
+        """
+        import ctypes
+        try:
+            lib, SchedParam, SCHED_FIFO, SCHED_OTHER = _pthread_sched_lib()
+            tid    = lib.pthread_self()
+            policy = ctypes.c_int(-1)
+            param  = SchedParam(0)
+            lib.pthread_getschedparam(tid, ctypes.byref(policy), ctypes.byref(param))
+
+            if policy.value == SCHED_FIFO:
+                param.sched_priority = 0
+                ret = lib.pthread_setschedparam(tid, SCHED_OTHER, ctypes.byref(param))
+                if ret == 0:
+                    log.info("[HTTP] Demoted SCHED_FIFO → SCHED_OTHER")
+                else:
+                    err = ctypes.get_errno()
+                    log.warning("[HTTP] Could not demote from SCHED_FIFO (errno=%d)", err)
+            else:
+                log.info("[HTTP] Already SCHED_OTHER, no demotion needed")
+        except Exception as exc:
+            log.warning("[HTTP] Scheduling demotion error: %s", exc)
+
+        try:
+            os.nice(10)
+            log.info("[HTTP] nice=+10 (lower priority)")
+        except Exception as exc:
+            log.debug("[HTTP] os.nice: %s", exc)
+
+    _ble_loop_ready = threading.Event()
+
+    def _run_ble_loop():
+        # Confirm or establish RT scheduling before entering the event loop.
+        _configure_ble_thread_scheduling()
+
+        async def _ble_runner():
+            global _ble_loop
+            _ble_loop = asyncio.get_running_loop()
+            _ble_loop_ready.set()
+            # Keep the loop alive; it is stopped when the process exits because
+            # this is a daemon thread.
+            await asyncio.Event().wait()
+
+        asyncio.run(_ble_runner())
+
+    _ble_thread = threading.Thread(target=_run_ble_loop, name="ble-loop", daemon=True)
+    _ble_thread.start()
+    if not _ble_loop_ready.wait(timeout=5):
+        log.error("BLE event loop failed to start within 5 s – aborting")
+        raise RuntimeError("BLE event loop startup timeout")
+    log.info("BLE event loop started on thread '%s'", _ble_thread.name)
+
+    # ── HTTP / uvicorn event loop (main thread) ─────────────────────────────
+    # Demote the HTTP thread from SCHED_FIFO (if set by systemd) to
+    # SCHED_OTHER + nice=+10 so the BLE thread always preempts it.
+    _configure_http_thread_scheduling()
+
     # Bind to localhost only for security: prevents network access, only frontend on same machine can connect
     uvicorn.run(app, host="127.0.0.1", port=5000, access_log=False)

src/auracast/server/system_update.sh

@@ -0,0 +1,90 @@
+#!/bin/bash
+# system_update.sh - Runs after git checkout in the Python system_update endpoint.
+# Called with the current working directory = project root.
+# All output is also written to /tmp/system_update.log for debugging.
+
+exec > >(tee -a /tmp/system_update.log) 2>&1
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="$(cd "$SCRIPT_DIR/../../.." && pwd)"
+POETRY="$HOME/.local/bin/poetry"
+OPENOCD_SRC="$HOME/sw_openocd"
+OPENOCD_REPO="ssh://git@gitea.summitwave.work:222/auracaster/sw_openocd.git"
+OPENOCD_BRANCH="change-8818"
+OPENOCD_MARKER="$OPENOCD_SRC/.last_built_commit"
+OPENOCD_DIR="$PROJECT_ROOT/src/openocd"
+
+echo "[system_update] Starting post-checkout update. project_root=$PROJECT_ROOT"
+
+# 1. poetry install
+echo "[system_update] Running poetry install..."
+(cd "$PROJECT_ROOT" && "$POETRY" install)
+if [ $? -ne 0 ]; then
+    echo "[system_update] ERROR: poetry install failed"
+    exit 1
+fi
+
+# 2. Clone/update and build sw_openocd if needed
+if [ ! -d "$OPENOCD_SRC" ]; then
+    echo "[system_update] Installing sw_openocd build dependencies..."
+    sudo apt install -y git build-essential libtool autoconf texinfo \
+        libusb-1.0-0-dev libftdi1-dev libhidapi-dev pkg-config || \
+        echo "[system_update] WARNING: apt install deps had errors, continuing"
+    sudo apt-get install -y pkg-config libjim-dev || \
+        echo "[system_update] WARNING: apt-get install libjim-dev had errors, continuing"
+
+    echo "[system_update] Cloning sw_openocd branch $OPENOCD_BRANCH..."
+    git clone --branch "$OPENOCD_BRANCH" --single-branch "$OPENOCD_REPO" "$OPENOCD_SRC"
+    if [ $? -ne 0 ]; then
+        echo "[system_update] ERROR: git clone sw_openocd failed"
+        exit 1
+    fi
+else
+    echo "[system_update] Updating sw_openocd..."
+    git -C "$OPENOCD_SRC" fetch origin "$OPENOCD_BRANCH"
+    git -C "$OPENOCD_SRC" checkout "$OPENOCD_BRANCH"
+    git -C "$OPENOCD_SRC" pull
+fi
+
+OPENOCD_COMMIT=$(git -C "$OPENOCD_SRC" rev-parse HEAD)
+LAST_BUILT=""
+[ -f "$OPENOCD_MARKER" ] && LAST_BUILT=$(cat "$OPENOCD_MARKER")
+
+if [ "$OPENOCD_COMMIT" != "$LAST_BUILT" ]; then
+    echo "[system_update] Building sw_openocd (commit $OPENOCD_COMMIT)..."
+
+    (cd "$OPENOCD_SRC" && ./bootstrap)
+    if [ $? -ne 0 ]; then echo "[system_update] ERROR: openocd bootstrap failed"; exit 1; fi
+
+    (cd "$OPENOCD_SRC" && ./configure --enable-bcm2835gpio --enable-sysfsgpio)
+    if [ $? -ne 0 ]; then echo "[system_update] ERROR: openocd configure failed"; exit 1; fi
+
+    (cd "$OPENOCD_SRC" && make)
+    if [ $? -ne 0 ]; then echo "[system_update] ERROR: openocd make failed"; exit 1; fi
+
+    (cd "$OPENOCD_SRC" && sudo make install)
+    if [ $? -ne 0 ]; then echo "[system_update] ERROR: openocd make install failed"; exit 1; fi
+
+    echo "$OPENOCD_COMMIT" > "$OPENOCD_MARKER"
+    echo "[system_update] sw_openocd built and installed (commit $OPENOCD_COMMIT)"
+else
+    echo "[system_update] sw_openocd up to date (commit $OPENOCD_COMMIT), skipping build"
+fi
+
+# 3. Flash firmware to both SWD interfaces
+FLASH_SCRIPT="$OPENOCD_DIR/flash.sh"
+HEX_FILE="$OPENOCD_DIR/merged.hex"
+
+for IFACE in swd0 swd1; do
+    echo "[system_update] Flashing $IFACE..."
+    (cd "$OPENOCD_DIR" && bash "$FLASH_SCRIPT" -i "$IFACE" -f "$HEX_FILE")
+    if [ $? -ne 0 ]; then
+        echo "[system_update] ERROR: flash $IFACE failed"
+        exit 1
+    fi
+    echo "[system_update] Flash $IFACE complete"
+done
+
+# 4. Restart services (this will kill this process too)
+echo "[system_update] Restarting services..."
+bash "$PROJECT_ROOT/src/service/update_and_run_server_and_frontend.sh"

src/auracast/utils/read_lc3_file.py

@@ -21,12 +21,12 @@ def read_lc3_file(filepath):
         logging.info('frame_duration %s', frame_duration)
         logging.info('stream_length %s', stream_length)
 
-        lc3_bytes= b''
+        chunks = []
         while True:
             b = f_lc3.read(2)
             if b == b'':
                 break
             lc3_frame_size = struct.unpack('=H', b)[0]
-            lc3_bytes += f_lc3.read(lc3_frame_size)
+            chunks.append(f_lc3.read(lc3_frame_size))
 
-        return lc3_bytes
+        return b''.join(chunks)

src/dep/dante_package/dante_data/activation/.gitkeep

@@ -0,0 +1 @@
+Placeholder file to have the activation folder available, otherwise dante activation script fails with 'Unable to write'.

src/dep/dante_package/dante_data/capability/dante.json

@@ -1,5 +1,5 @@
 {
-	"trialMode": true,
+	"trialMode": false,
 	"$schema": "./dante.json_schema.json",
 	"platform":
 	{
@@ -16,7 +16,7 @@
 				48000
 			],
 		"samplesPerPeriod" : 16,
-		"periodsPerBuffer" : 300,
+		"periodsPerBuffer" : 150,
 		"networkLatencyMinMs" : 2,
 		"networkLatencyDefaultMs" : 5,
 		"supportedEncodings" :
@@ -24,7 +24,10 @@
 				"PCM16"
 			],
 		"defaultEncoding" : "PCM16",
-		"numDepCores" : 1
+		"numDepCores" : 
+			[
+				3
+			]
 	},
 	"network" :
 	{
@@ -50,31 +53,32 @@
 	"alsaAsrc":
 	{
 		"enableAlsaAsrc": true,
+		"cpuAffinity": 3,
 		"deviceConfigurations": [
 			{
-			"deviceIdentifier": "hw:0,0",
+			"deviceIdentifier": "hw:6,0,0",
 			"direction": "playback",
 			"bitDepth": 16,
 			"numOpenChannels": 6,
 			"alsaChannelRange": "0-5",
 			"danteChannelRange": "0-5",
-			"bufferSize": 4800,
+			"bufferSize": 960,
 			"samplesPerPeriod": 16
 			}
 		]
 	},
 	"product" :
 	{
-		"manfId" : "Audinate",
+		"manfId" : "SummitFC",
-		"manfName" : "Audinate Pty Ltd",
+		"manfName" : "Summitwave FlexCo",
-		"modelId" : "OEMDEP",
+		"modelId" : "TX",
-		"modelName" : "Linux Dante Embedded Platform",
+		"modelName" : "Summitwave TX",
 		"modelVersion" :
 			{
-				"major" : 9,
+				"major" : 1,
-				"minor" : 9,
+				"minor" : 0,
-				"bugfix" : 99
+				"bugfix" : 0
 			},
-		"devicePrefix" : "DEP"
+		"devicePrefix" : "SW-TX"
 	}
 }

src/misc/asound.conf

@@ -6,8 +6,8 @@ pcm.ch1 {
         channels 2
         rate 48000
         format S16_LE
-        period_size 120    
+        period_size 240    
-        buffer_size 240    
+        buffer_size 960    
     }
     bindings.0  0
 }
@@ -21,8 +21,8 @@ pcm.ch2 {
         channels 2
         rate 48000
         format S16_LE
-        period_size 120
+        period_size 240
-        buffer_size 240
+        buffer_size 960
     }    
     bindings.0  1
 }

src/misc/install_asoundconf.sh

@@ -1 +1,2 @@
-sudo cp src/misc/asound.conf /etc/asound.conf
+SCRIPT_DIR="$(cd "$(dirname "$0")" && pwd)"
+sudo cp "$SCRIPT_DIR/asound.conf" /etc/asound.conf

src/openocd/flash.sh

@@ -0,0 +1,56 @@
+#!/bin/bash
+set -e
+
+INTERFACE="swd0"
+HEX_FILE=""
+
+usage() {
+  echo "Usage: $0 -f <hex_file> [-i swd0|swd1]"
+  exit 1
+}
+
+while getopts "f:i:h" opt; do
+  case "$opt" in
+    f) HEX_FILE="$OPTARG" ;;
+    i)
+      if [[ "$OPTARG" == "swd0" || "$OPTARG" == "swd1" ]]; then
+        INTERFACE="$OPTARG"
+      else
+        usage
+      fi
+      ;;
+    h) usage ;;
+    *) usage ;;
+  esac
+done
+
+[[ -n "$HEX_FILE" ]] || usage
+[[ -f "$HEX_FILE" ]] || { echo "HEX file not found: $HEX_FILE"; exit 1; }
+
+sudo openocd \
+  -f ./raspberrypi-${INTERFACE}.cfg \
+  -c "init" \
+  -c "reset init" \
+  -c "flash banks" \
+  -c "flash write_image $HEX_FILE" \
+  -c "verify_image $HEX_FILE" \
+  -c "reset run" \
+  -c "shutdown"
+
+sudo openocd \
+  -f ./raspberrypi-${INTERFACE}.cfg \
+  -c "init" \
+  -c "nrf54l.dap apreg 2 0x000 0x1" \
+  -c "sleep 100" \
+  -c "nrf54l.dap apreg 2 0x000 0x0" \
+  -c "shutdown"
+
+sudo openocd \
+  -f ./raspberrypi-${INTERFACE}.cfg \
+  -c "init" \
+  -c "nrf54l.dap apreg 2 0x000 0x4" \
+  -c "sleep 100" \
+  -c "nrf54l.dap apreg 2 0x000 0x0" \
+  -c "shutdown"
+
+echo "Flashing complete."

src/openocd/raspberrypi-swd0.cfg

@@ -5,4 +5,9 @@ adapter gpio swdio 26
 #adapter gpio trst 26
 #reset_config trst_only
 
+
+source [find target/nordic/nrf54l.cfg]
+
+flash bank $_CHIPNAME.flash nrf54 0x00000000 0 0 0 $_TARGETNAME
+
 adapter speed 1000

src/openocd/raspberrypi-swd1.cfg

@@ -5,4 +5,9 @@ adapter gpio swdio 24
 #adapter gpio trst 27
 #reset_config trst_only
 
+
+source [find target/nordic/nrf54l.cfg]
+
+flash bank $_CHIPNAME.flash nrf54 0x00000000 0 0 0 $_TARGETNAME
+
 adapter speed 1000

src/service/10-link-local-mgmt

@@ -0,0 +1,64 @@
+#!/bin/bash
+# NetworkManager dispatcher script: 10-link-local-mgmt
+#
+# Temporarily suppresses IPv4 link-local when a DHCP address is available,
+# using nmcli device modify (active session only, NOT saved to the profile).
+# The persistent profile always keeps ipv4.link-local=enabled so that
+# direct-connect (no DHCP) plug-ins always activate and trigger events.
+# Avahi is reloaded on each event — no /etc/avahi/hosts file, avahi uses
+# natural per-interface advertisement so each segment gets the right IP.
+#
+# Triggers: up, down, dhcp4-change on ethernet interfaces
+# Install to: /etc/NetworkManager/dispatcher.d/10-link-local-mgmt
+# Permissions: root:root 0755
+
+INTERFACE="$1"
+ACTION="$2"
+# Only handle ethernet interfaces
+if [[ ! "$INTERFACE" =~ ^eth ]]; then
+    exit 0
+fi
+
+reload_avahi() {
+    systemctl reload avahi-daemon 2>/dev/null || systemctl restart avahi-daemon 2>/dev/null
+    logger -t nm-link-local "[$INTERFACE] $ACTION — avahi reloaded"
+}
+
+case "$ACTION" in
+    up)
+        # On 'up' the interface may still carry a stale DHCP address from the previous
+        # session (NM hasn't cleaned it up yet). Reading ip-addr here is unreliable.
+        # Always re-enable link-local as a clean slate; let dhcp4-change suppress it
+        # later if a real DHCP lease is obtained.
+        logger -t nm-link-local "[$INTERFACE] Up — ensuring link-local active (clean slate)"
+        (sleep 2 && nmcli device modify "$INTERFACE" ipv4.link-local enabled 2>/dev/null \
+            && logger -t nm-link-local "[$INTERFACE] Link-local explicitly enabled on up") &
+        reload_avahi
+        ;;
+
+    dhcp4-change)
+        # dhcp4-change fires only when DHCP actually succeeds (new/renewed lease).
+        # At this point the DHCP IP is reliably present — safe to read and suppress link-local.
+        DHCP_IP=$(ip -4 addr show "$INTERFACE" 2>/dev/null \
+            | grep -oP '(?<=inet\s)\d+(\.\d+){3}' \
+            | grep -v '^127\.' \
+            | grep -v '^169\.254\.' \
+            | head -n1)
+
+        if [ -n "$DHCP_IP" ]; then
+            logger -t nm-link-local "[$INTERFACE] DHCP $DHCP_IP confirmed — suppressing link-local (session only)"
+            # Run in background after a delay — nmcli blocks on NM, which is waiting for
+            # this dispatcher to return, causing a deadlock if called synchronously.
+            (sleep 2 && nmcli device modify "$INTERFACE" ipv4.link-local disabled 2>/dev/null \
+                && logger -t nm-link-local "[$INTERFACE] Link-local suppressed for current session") &
+        fi
+        reload_avahi
+        ;;
+
+    down)
+        # NOTE: a carrier-change does NOT fully reset session-level 'device modify' state.
+        # The re-enable is therefore handled in the 'up' handler when no DHCP is detected.
+        logger -t nm-link-local "[$INTERFACE] Down — link-local will be re-enabled on next up without DHCP"
+        reload_avahi
+        ;;
+esac

src/service/auracast-frontend.service

@@ -10,6 +10,8 @@ WorkingDirectory=/home/caster/bumble-auracast/src/auracast/server
 ExecStart=/home/caster/bumble-auracast/src/auracast/server/start_frontend_https.sh
 Restart=on-failure
 Environment=LOG_LEVEL=INFO
+AllowedCPUs=0
+CPUAffinity=0
 
 [Install]
 WantedBy=multi-user.target

src/service/auracast-script.service

@@ -9,6 +9,8 @@ ExecStart=/home/caster/bumble-auracast/.venv/bin/python src/auracast/multicast_s
 Restart=on-failure
 Environment=PYTHONUNBUFFERED=1
 Environment=LOG_LEVEL=INFO
+AllowedCPUs=0
+CPUAffinity=0
 
 [Install]
 WantedBy=default.target

src/service/auracast-server.service

@@ -1,6 +1,7 @@
 [Unit]
 Description=Auracast Backend Server
-After=network.target
+After=network.target dep.service
+Wants=dep.service
 
 [Service]
 Type=simple
@@ -10,8 +11,10 @@ Restart=on-failure
 Environment=PYTHONUNBUFFERED=1
 Environment=LOG_LEVEL=INFO
 CPUSchedulingPolicy=fifo
-CPUSchedulingPriority=99
+CPUSchedulingPriority=10
 LimitRTPRIO=99
+AllowedCPUs=0,1,2
+CPUAffinity=0,1,2
 
 [Install]
 WantedBy=default.target

src/service/dep.service

@@ -0,0 +1,13 @@
+[Unit]
+Description=DEP (Dante Embedded Platform) Container
+After=network.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+WorkingDirectory=/home/caster/bumble-auracast/src/dep/dante_package
+ExecStart=/bin/bash dep.sh start
+ExecStop=/bin/bash dep.sh stop
+
+[Install]
+WantedBy=multi-user.target

src/service/pipewire-aes67.service

@@ -9,6 +9,8 @@ ExecStartPre=/bin/sh -lc 'for i in $(seq 1 60); do ip route show default >/dev/n
 ExecStart=/usr/bin/pipewire-aes67 -c /home/caster/bumble-auracast/src/service/aes67/pipewire-aes67.conf
 Restart=always
 RestartSec=5s
+AllowedCPUs=0
+CPUAffinity=0
 # Avoid StartLimitHit on quick failures during boot; let RestartSec handle pacing
 StartLimitIntervalSec=0
 

src/service/ptp_aes67.service

@@ -6,6 +6,8 @@ After=network.target
 Type=simple
 ExecStart=/usr/sbin/ptp4l -i eth0 -f /home/caster/bumble-auracast/src/service/aes67/ptp_aes67_1.conf
 Restart=on-failure
+AllowedCPUs=0
+CPUAffinity=0
 StandardOutput=journal
 StandardError=journal
 

src/service/update_and_run_server_and_frontend.sh

@@ -8,30 +8,43 @@ set -e
 # Enable link-local for all wired ethernet connections
 while IFS=: read -r name type; do
     if [[ "$type" == *"ethernet"* ]]; then
-        echo "Enabling IPv4 link-local for connection: $name"
+        echo "Configuring connection: $name"
+        # link-local: always enabled so direct-connect (no DHCP) works immediately
         sudo nmcli connection modify "$name" ipv4.link-local enabled 2>/dev/null || echo "Failed to modify $name"
+        # may-fail=yes: do NOT tear down the connection when DHCP times out.
+        # Without this, NM declares ip-config-unavailable after the 45s DHCP timeout
+        # and enters a reconnect loop that causes ~1.5 min outages every ~45 seconds.
+        sudo nmcli connection modify "$name" ipv4.may-fail yes 2>/dev/null || echo "Failed to set may-fail on $name"
+        # Infinite DHCP timeout: NM keeps retrying DHCP in the background but never
+        # declares ip-config-unavailable. This prevents the 45s reconnect loop that
+        # kills the link-local address in direct-connect (no DHCP server) scenarios.
+        sudo nmcli connection modify "$name" ipv4.dhcp-timeout infinity 2>/dev/null || echo "Failed to set dhcp-timeout on $name"
         sudo nmcli connection up "$name" 2>/dev/null || echo "Failed to bring up $name"
     fi
 done < <(nmcli -t -f NAME,TYPE connection show)
 
-# Configure Avahi to prefer DHCP address over static fallback for mDNS
-# Get the DHCP-assigned IP (first non-localhost, non-192.168.42.10 IP)
-DHCP_IP=$(ip -4 addr show eth0 2>/dev/null | grep -oP '(?<=inet\s)\d+(\.\d+){3}' | grep -v '^127\.' | grep -v '^169\.254\.' | head -n1)
-HOSTNAME=$(hostname)
 
-if [ -n "$DHCP_IP" ]; then
+# Remove stale avahi hosts pin — this file overrides per-interface advertisement
-    echo "DHCP address detected: $DHCP_IP, configuring Avahi to prefer it for mDNS."
+# and causes mDNS to always resolve to eth0's IP regardless of which interface
-    # Add entry to /etc/avahi/hosts to explicitly map hostname to DHCP IP
+# the query arrived on, breaking eth1 mDNS entirely.
-    sudo mkdir -p /etc/avahi
+sudo rm -f /etc/avahi/hosts
-    echo "$DHCP_IP $HOSTNAME $HOSTNAME.local" | sudo tee /etc/avahi/hosts > /dev/null
+sudo systemctl restart avahi-daemon
-    # Restart avahi to apply the hosts file
+
-    sudo systemctl restart avahi-daemon
+# Ensure Loopback is loaded with a fixed name and index 
-else
+# Needed for dante
-    echo "No DHCP address detected, mDNS will use link local"
+# TODO image when we create the next image this should be part of it
-    # Remove hosts file to let Avahi advertise all IPs
+echo "options snd-aloop index=6 id=Loopback pcm_substreams=6" | sudo tee /etc/modprobe.d/snd-aloop.conf
-    sudo rm -f /etc/avahi/hosts
+echo snd-aloop | sudo tee /etc/modules-load.d/snd-aloop.conf
-    sudo systemctl restart avahi-daemon
+
-fi
+
+
+# Install NetworkManager dispatcher script for link-local / Avahi management
+sudo cp /home/caster/bumble-auracast/src/service/10-link-local-mgmt /etc/NetworkManager/dispatcher.d/10-link-local-mgmt
+sudo chown root:root /etc/NetworkManager/dispatcher.d/10-link-local-mgmt
+sudo chmod 755 /etc/NetworkManager/dispatcher.d/10-link-local-mgmt
+
+# Copy system service file for DEP
+sudo cp /home/caster/bumble-auracast/src/service/dep.service /etc/systemd/system/dep.service
 
 # Copy system service file for frontend
 sudo cp /home/caster/bumble-auracast/src/service/auracast-frontend.service /etc/systemd/system/auracast-frontend.service
@@ -40,20 +53,25 @@ sudo cp /home/caster/bumble-auracast/src/service/auracast-frontend.service /etc/
 mkdir -p /home/caster/.config/systemd/user
 cp /home/caster/bumble-auracast/src/service/auracast-server.service /home/caster/.config/systemd/user/auracast-server.service
 
-# Reload systemd for frontend
+# Reload systemd for frontend and dep
 sudo systemctl daemon-reload
 # Reload user systemd for server
 systemctl --user daemon-reload
 
+# Enable DEP to start on boot (system)
+sudo systemctl enable dep.service
 # Enable frontend to start on boot (system)
 sudo systemctl enable auracast-frontend.service
 # Enable server to start on boot (user)
 systemctl --user enable auracast-server.service
 
-# Restart both
+# Restart all
+sudo systemctl restart dep.service
+
 sudo systemctl restart auracast-frontend.service
 systemctl --user restart auracast-server.service
 
 #print status
+sudo systemctl status dep.service --no-pager
 sudo systemctl status auracast-frontend.service --no-pager
 systemctl --user status auracast-server.service --no-pager