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292 | class PartectorBleConnection:
SERVICE_UUID = "0bd51666-e7cb-469b-8e4d-2742f1ba77cc"
CHAR_UUIDS = {
"std": "e7add780-b042-4876-aae1-112855353cc1",
"aux": "e7add781-b042-4876-aae1-112855353cc1",
"write": "e7add782-b042-4876-aae1-112855353cc1",
"read": "e7add783-b042-4876-aae1-112855353cc1",
"size_dist": "e7add784-b042-4876-aae1-112855353cc1",
}
# static methods ###############################################################################
@staticmethod
def create_connection_queue() -> asyncio.Queue[NaneosDeviceDataPoint]:
"""Create a queue for the connection data."""
# Increased maxsize to 500 to handle bursts from multiple devices
# Prevents message loss on Raspberry Pi with many concurrent connections
queue_connection: asyncio.Queue[NaneosDeviceDataPoint] = asyncio.Queue(maxsize=500)
return queue_connection
# == Lifecycle and Context Management ==========================================================
def __init__(
self,
device: BLEDevice,
loop: asyncio.AbstractEventLoop,
serial_number: int,
queue: asyncio.Queue[NaneosDeviceDataPoint],
) -> None:
"""
Initializes the BLE connection with the given device, event loop, and queue.
Args:
device (BLEDevice): The BLE device to connect to.
loop (asyncio.AbstractEventLoop): The event loop to run the connection in.
serial_number (int): The serial number of the device.
"""
self.SERIAL_NUMBER = serial_number
self._device_type = NaneosDeviceDataPoint.DEV_TYPE_P2 # Thats the deafault value
self._data = NaneosDeviceDataPoint()
self._next_ts = 0.0
self._last_aux_data_ts = time.time()
self._queue = queue
# Decode queue to decouple decoding from BLE callbacks
# This prevents blocking the event loop when decoding heavy data
self._decode_queue: asyncio.Queue = asyncio.Queue(maxsize=200)
self._device = device
self._loop = loop
self._task: asyncio.Task | None = None
self._stop_event = asyncio.Event()
self._stop_event.set() # stopped by default
self._client = BleakClient(device, self._disconnect_callback, timeout=10)
async def __aenter__(self) -> PartectorBleConnection:
self.start()
return self
async def __aexit__(self, exc_type, exc_val, exc_tb) -> None:
await self.stop()
# == Public Methods ============================================================================
def start(self) -> None:
"""Starts the scanner."""
if not self._stop_event.is_set():
logger.warning("SN{self._serial_number}: start() called while already running")
return
self._stop_event.clear()
self._task = self._loop.create_task(self._run())
async def stop(self) -> None:
"""Stops the scanner."""
self._stop_event.set()
if self._task and not self._task.done():
await self._task
logger.info(f"SN{self.SERIAL_NUMBER}: PartectorBleConnection stopped")
async def _run(self) -> None:
waiting_seconds = 0
try:
self._next_ts = int(time.time()) + 1.0
# Create decode task to run in parallel
# This prevents decoding from blocking the event loop
self._loop.create_task(self._decode_routine())
while not self._stop_event.is_set():
try:
if self._last_aux_data_ts + 60 < time.time():
logger.info(
f"SN{self.SERIAL_NUMBER}: No aux data received for 60 seconds, disconnecting to reset."
)
await self._disconnect_gracefully()
self._last_aux_data_ts = time.time()
waiting_seconds = 5 # wait 5 seconds before reconnecting
waiting_seconds = max(0, waiting_seconds - 1)
wait = self._next_ts - time.time()
if wait > 0:
await asyncio.sleep(wait)
self._next_ts += 1.0
else:
if self._client.is_connected:
logger.info(f"SN{self.SERIAL_NUMBER}: Waiting time negative: {wait}")
self._next_ts = int(time.time()) + 1.0
if self._client.is_connected:
if (
self._device_type == NaneosDeviceDataPoint.DEV_TYPE_P2PRO
and self._data.particle_number_10nm is None
and self._data.particle_number_16nm is None
and self._data.particle_number_26nm is None
and self._data.particle_number_43nm is None
and self._data.particle_number_70nm is None
and self._data.particle_number_114nm is None
and self._data.particle_number_185nm is None
and self._data.particle_number_300nm is None
):
self._data.particle_number_concentration = None
self._data.average_particle_diameter = None
self._queue.put_nowait(self._data)
self._data = NaneosDeviceDataPoint(
device_type=self._device_type,
serial_number=self.SERIAL_NUMBER,
connection_type=NaneosDeviceDataPoint.CONN_TYPE_CONNECTED,
# TODO: add firware version from device here
)
continue
if waiting_seconds == 0:
await self._client.connect(timeout=5) # 5 seconds for windows...
if self._client.is_connected:
await self._client.start_notify(
self.CHAR_UUIDS["std"], self._callback_std
)
await self._client.start_notify(
self.CHAR_UUIDS["aux"], self._callback_aux
)
await self._client.start_notify(
self.CHAR_UUIDS["size_dist"], self._callback_size_dist
)
logger.info(f"SN{self.SERIAL_NUMBER}: Connected to {self._device.address}")
self._next_ts = int(time.time()) + 1.0
except asyncio.TimeoutError:
logger.info(f"SN{self.SERIAL_NUMBER}: Connection timeout.")
waiting_seconds = 30
await asyncio.sleep(0.5)
except BleakDeviceNotFoundError:
logger.info(f"SN{self.SERIAL_NUMBER}: Device not found or probably old BLE.")
waiting_seconds = 30
await asyncio.sleep(0.5)
except Exception as e:
# if exception contains "not found" increase waiting time to 30 seconds and do not spam
if "not found" in str(e).lower():
logger.info(
f"SN{self.SERIAL_NUMBER}: Device not found or probably old BLE: {e}"
)
waiting_seconds = 30
else:
logger.warning(f"SN{self.SERIAL_NUMBER}: Unknown exception: {e}")
await asyncio.sleep(0.5)
except asyncio.CancelledError:
logger.warning(f"SN{self.SERIAL_NUMBER}: _run task cancelled.")
except Exception as e:
logger.exception(f"SN{self.SERIAL_NUMBER}: _run task failed: {e}")
finally:
await self._disconnect_gracefully()
async def _decode_routine(self) -> None:
"""Asynchronously decodes BLE data from the decode queue.
This runs in parallel with the main connection loop, preventing
decoding from blocking the event loop when handling multiple connections.
"""
while not self._stop_event.is_set():
try:
# Non-blocking check with timeout to allow graceful shutdown
try:
char_type, data = await asyncio.wait_for(self._decode_queue.get(), timeout=0.5)
except asyncio.TimeoutError:
continue
# Update timestamp for all decodings
self._data.unix_timestamp = int(time.time() * 1000)
# Decode based on characteristic type
if char_type == "std":
self._data = PartectorBleDecoderStd.decode(data, data_structure=self._data)
logger.debug(f"SN{self.SERIAL_NUMBER}: Decoded std: {data.hex()}")
elif char_type == "aux":
# Check for aux error data
if len(data) >= 2 and data[0] == 255 and data[1] == 255:
self._data = PartectorBleDecoderAuxError.decode(
data, data_structure=self._data
)
else:
self._data = PartectorBleDecoderAux.decode(data, data_structure=self._data)
logger.debug(f"SN{self.SERIAL_NUMBER}: Decoded aux: {data.hex()}")
elif char_type == "size_dist":
self._device_type = NaneosDeviceDataPoint.DEV_TYPE_P2PRO
self._data = PartectorBleDecoderSize.decode(data, data_structure=self._data)
logger.debug(f"SN{self.SERIAL_NUMBER}: Decoded size_dist: {data.hex()}")
except Exception as e:
logger.warning(f"SN{self.SERIAL_NUMBER}: Error in decode routine: {e}")
async def _disconnect_gracefully(self) -> None:
if not self._client.is_connected:
return
try:
await asyncio.wait_for(self._client.stop_notify(self.CHAR_UUIDS["std"]), timeout=1)
await asyncio.sleep(0.5) # wait for windows to free resources
await asyncio.wait_for(self._client.stop_notify(self.CHAR_UUIDS["aux"]), timeout=1)
await asyncio.sleep(0.5) # wait for windows to free resources
await asyncio.wait_for(
self._client.stop_notify(self.CHAR_UUIDS["size_dist"]), timeout=1
)
await asyncio.sleep(0.5) # wait for windows to free resources
except Exception as e:
logger.debug(f"SN{self.SERIAL_NUMBER}: Failed to stop notify: {e}")
try:
await asyncio.wait_for(self._client.disconnect(), timeout=1)
await asyncio.sleep(0.5) # wait for windows to free resources
except Exception as e:
logger.debug(f"SN{self.SERIAL_NUMBER}: Failed to disconnect: {e}")
def _disconnect_callback(self, client: BleakClient) -> None:
"""Callback on disconnect."""
logger.debug(f"SN{self.SERIAL_NUMBER}: Disconnect callback called")
def _callback_std(self, characteristic: BleakGATTCharacteristic, data: bytearray) -> None:
"""Callback on data received (std characteristic).
Non-blocking: puts data in decode queue instead of decoding directly.
Actual decoding happens asynchronously in _decode_routine().
"""
try:
self._decode_queue.put_nowait(("std", bytes(data)))
except asyncio.QueueFull:
logger.warning(f"SN{self.SERIAL_NUMBER}: Decode queue full, dropping std data")
def _callback_aux(self, characteristic: BleakGATTCharacteristic, data: bytearray) -> None:
"""Callback on data received (aux characteristic).
Non-blocking: puts data in decode queue instead of decoding directly.
Actual decoding happens asynchronously in _decode_routine().
"""
self._last_aux_data_ts = time.time()
try:
self._decode_queue.put_nowait(("aux", bytes(data)))
except asyncio.QueueFull:
logger.warning(f"SN{self.SERIAL_NUMBER}: Decode queue full, dropping aux data")
def _callback_size_dist(self, characteristic: BleakGATTCharacteristic, data: bytearray) -> None:
"""Callback on data received (size_dist characteristic).
Non-blocking: puts data in decode queue instead of decoding directly.
Actual decoding happens asynchronously in _decode_routine().
"""
try:
self._decode_queue.put_nowait(("size_dist", bytes(data)))
except asyncio.QueueFull:
logger.warning(f"SN{self.SERIAL_NUMBER}: Decode queue full, dropping size_dist data")
|