From 7cd720aa2038d6b5138f5f1cfc03f56649e32f86 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Thu, 30 May 2024 14:15:52 +0200
Subject: [PATCH 01/30] add IPv4Transport and IPv4TransportHandle classes

---
 src/seabreeze/pyseabreeze/transport.py | 192 +++++++++++++++++++++++++
 1 file changed, 192 insertions(+)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index 43068a50..11e7cf8b 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -20,6 +20,8 @@
 import usb.core
 import usb.util
 
+import socket
+
 from seabreeze.pyseabreeze.types import PySeaBreezeProtocol
 from seabreeze.pyseabreeze.types import PySeaBreezeTransport
 
@@ -364,3 +366,193 @@ def get_name_from_pyusb_backend(backend: usb.backend.IBackend) -> str | None:
     if not module:
         return None
     return module.__name__.split(".")[-1]
+
+#  ___ ____        _  _
+# |_ _|  _ \__   _| || |
+#  | || |_) \ \ / / || |_
+#  | ||  __/ \ V /|__   _|
+# |___|_|     \_/    |_|
+
+
+# this can and should be opaque to pyseabreeze
+class IPv4TransportHandle:
+    def __init__(self, socket: socket.socket, address: str = None, port: int = None) -> None:
+        """encapsulation for IPv4 socket classes
+
+        Parameters
+        ----------
+
+        """
+        self.socket: socket.socket = socket
+        # TODO check if socket is connected and get address via socket (socket.getpeername())
+        self.identity: tuple[str, int] = (address, port)
+
+    def close(self) -> None:
+        # TODO check for exceptions that close() might throw
+        self.socket.close()
+
+    def __del__(self) -> None:
+        self.close()
+        self.socket = None
+
+
+class IPv4Transport(PySeaBreezeTransport[IPv4TransportHandle]):
+    """implementation of the IPv4 socket transport interface for spectrometers"""
+
+    _required_init_kwargs = (
+        "ipv4_address",
+        "ipv4_port",
+        "ipv4_protocol",
+    )
+
+    # add logging
+    _log = logging.getLogger(__name__)
+
+    def __init__(
+        self,
+        ipv4_address: str,
+        ipv4_port: int,
+        ipv4_protocol: type[PySeaBreezeProtocol],
+    ) -> None:
+        super().__init__()
+        self._address = ipv4_address
+        self._port = ipv4_port
+        self._protocol_cls = ipv4_protocol
+        # internal state
+        self._device: IPv4TransportHandle | None = None
+        self._opened: bool | None = None
+        self._protocol: PySeaBreezeProtocol | None = None
+
+    def open_device(self, device: IPv4TransportHandle) -> None:
+        if not isinstance(device, IPv4TransportHandle):
+            raise TypeError("device needs to be an IPv4TransportHandle")
+        # TODO handle possible exceptions
+        self._device = device
+        self._opened = True
+
+        # This will initialize the communication protocol
+        if self._opened:
+            self._protocol = self._protocol_cls(self)
+
+    @property
+    def is_open(self) -> bool:
+        return self._opened or False
+
+    def close_device(self) -> None:
+        if self._device is not None:
+            self._device.close()
+            self._device = None
+        self._opened = False
+        self._protocol = None
+
+    def write(self, data: bytes, timeout_ms: int | None = None, **kwargs: Any) -> int:
+        if self._device is None:
+            raise RuntimeError("device not opened")
+        if kwargs:
+            warnings.warn(f"kwargs provided but ignored: {kwargs}")
+        if timeout_ms:
+            self._device.socket.settimeout(timeout_ms / 1000.0)
+        return self._device.socket.send(data)
+
+    def read(
+        self,
+        size: int | None = None,
+        timeout_ms: int | None = None,
+        mode: str | None = None,
+        **kwargs: Any,
+    ) -> bytes:
+        if self._device is None:
+            raise RuntimeError("device not opened")
+        if size is None:
+            # use minimum packet size (no payload)
+            size = 64
+        if kwargs:
+            warnings.warn(f"kwargs provided but ignored: {kwargs}")
+        if timeout_ms:
+            self._device.socket.settimeout(timeout_ms / 1000.0)
+        data = bytearray(size)
+        toread = size
+        view = memoryview(data)
+        while toread:
+            nbytes = self._device.socket.recv_into(view, toread)
+            view = view[nbytes:]
+            toread -= nbytes
+        return bytes(data)
+
+    @property
+    def default_timeout_ms(self) -> int:
+        if not self._device:
+            raise RuntimeError("no protocol instance available")
+        timeout = self._device.socket.gettimeout()
+        if not timeout:
+            return 10000
+        return int(timeout * 1000) # type: ignore
+
+    @property
+    def protocol(self) -> PySeaBreezeProtocol:
+        if self._protocol is None:
+            raise RuntimeError("no protocol instance available")
+        return self._protocol
+
+    @classmethod
+    def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
+        """list IPv4 devices for all available spectrometers
+
+        Note: this includes spectrometers that are currently opened in other
+        processes on the machine.
+
+        Yields
+        ------
+        devices : IPv4TransportHandle
+            unique socket devices for each available spectrometer
+        """
+        # TODO use multicast to discover potential spectrometers
+        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        # FIXME this uses the default address only
+        sock.connect(('192.168.254.254', 57357))
+        for dev in range(1):
+            yield IPv4TransportHandle(sock)
+
+    @classmethod
+    def register_model(cls, model_name: str, **kwargs: Any) -> None:
+        # TODO implement e.g. IP to model mapping?
+        print(f"Trying to register {model_name} with {kwargs}")
+        pass
+
+    @classmethod
+    def supported_model(cls, device: IPv4TransportHandle) -> str | None:
+        """return supported model
+
+        Parameters
+        ----------
+        device : IPv4TransportHandle
+        """
+        # TODO implement this method
+        if not isinstance(device, IPv4TransportHandle):
+            return None
+        # noinspection PyUnresolvedReferences
+        # FIXME return something other then a hard-coded string
+        return "HDX"
+
+    @classmethod
+    def specialize(cls, model_name: str, **kwargs: Any) -> type[IPv4Transport]:
+        # TODO check that this makes sense for the ipv4 transport
+        assert set(kwargs) == set(cls._required_init_kwargs)
+        # ipv4 transport register automatically on registration
+        cls.register_model(model_name, **kwargs)
+        specialized_class = type(
+            f"IPv4Transport{model_name}",
+            (cls,),
+            {"__init__": partialmethod(cls.__init__, **kwargs)},
+        )
+        return specialized_class
+
+    @classmethod
+    def initialize(cls, **_kwargs: Any) -> None:
+        # TODO implement socket resent (close/open?)
+        pass
+
+    @classmethod
+    def shutdown(cls, **_kwargs: Any) -> None:
+        # TODO implement
+        pass

From 04c2a2bca75aaa21a78744b7b9064382acd72474 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Thu, 30 May 2024 14:16:53 +0200
Subject: [PATCH 02/30] pyseabreeze: add basic IPv4 support

---
 src/seabreeze/pyseabreeze/api.py | 23 +++++++++++++++++++----
 1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/api.py b/src/seabreeze/pyseabreeze/api.py
index 42622960..cefe0f12 100644
--- a/src/seabreeze/pyseabreeze/api.py
+++ b/src/seabreeze/pyseabreeze/api.py
@@ -21,6 +21,8 @@
 from seabreeze.pyseabreeze.transport import USBTransportDeviceInUse
 from seabreeze.pyseabreeze.transport import USBTransportError
 from seabreeze.pyseabreeze.transport import USBTransportHandle
+from seabreeze.pyseabreeze.transport import IPv4Transport
+from seabreeze.pyseabreeze.transport import IPv4TransportHandle
 from seabreeze.types import SeaBreezeAPI as _SeaBreezeAPIProtocol
 
 if TYPE_CHECKING:
@@ -35,20 +37,20 @@
 ] = weakref.WeakValueDictionary()
 
 
-def _seabreeze_device_factory(device: USBTransportHandle) -> SeaBreezeDevice:
+def _seabreeze_device_factory(device: USBTransportHandle | IPv4TransportHandle) -> SeaBreezeDevice:
     """return existing instances instead of creating temporary ones
 
     Parameters
     ----------
-    device : USBTransportHandle
+    device : USBTransportHandle | IPv4TransportHandle
 
     Returns
     -------
     dev : SeaBreezeDevice
     """
     global _seabreeze_device_instance_registry
-    if not isinstance(device, USBTransportHandle):
-        raise TypeError("needs to be instance of USBTransportHandle")
+    if not isinstance(device, USBTransportHandle) and not isinstance(device, IPv4TransportHandle):
+        raise TypeError(f"needs to be instance of USBTransportHandle or IPv4TransportHandle and not '{type(device)}'")
     ident = device.identity
     try:
         return _seabreeze_device_instance_registry[ident]
@@ -127,6 +129,19 @@ def list_devices(self) -> list[_SeaBreezeDevice]:
                 else:
                     dev.close()
             devices.append(dev)  # type: ignore
+        for ipv4_dev in IPv4Transport.list_devices(**self._kwargs):
+            # get the correct communication interface
+            dev = _seabreeze_device_factory(ipv4_dev)
+            if not dev.is_open:
+                # opening the device will populate its serial number
+                try:
+                    dev.open()
+                except Exception:
+                    # TODO specify expected exception
+                    raise
+                #else:
+                #    dev.close()
+            devices.append(dev)  # type: ignore
         return devices
 
     # note: to be fully consistent with cseabreeze this shouldn't be a staticmethod

From 136a805503d9142616288f21d7488c87887a0ce6 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Thu, 30 May 2024 14:17:37 +0200
Subject: [PATCH 03/30] devices: add support for IPv4

---
 src/seabreeze/pyseabreeze/devices.py | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/devices.py b/src/seabreeze/pyseabreeze/devices.py
index c56ff73c..8f9e7eec 100644
--- a/src/seabreeze/pyseabreeze/devices.py
+++ b/src/seabreeze/pyseabreeze/devices.py
@@ -21,6 +21,7 @@
 from seabreeze.pyseabreeze.protocol import OBPProtocol
 from seabreeze.pyseabreeze.protocol import OOIProtocol
 from seabreeze.pyseabreeze.transport import USBTransport
+from seabreeze.pyseabreeze.transport import IPv4Transport
 from seabreeze.pyseabreeze.types import PySeaBreezeTransport
 from seabreeze.types import SeaBreezeFeatureAccessor
 
@@ -312,7 +313,7 @@ def __new__(cls: type[DT], raw_device: Any = None) -> SeaBreezeDevice:
             raise SeaBreezeError(
                 "Don't instantiate SeaBreezeDevice directly. Use `SeabreezeAPI.list_devices()`."
             )
-        for transport in {USBTransport}:
+        for transport in {USBTransport, IPv4Transport}:
             supported_model = transport.supported_model(raw_device)
             if supported_model is not None:
                 break
@@ -365,7 +366,7 @@ def __repr__(self) -> str:
         return f"<SeaBreezeDevice {self.model}:{self.serial_number}>"
 
     def open(self) -> None:
-        """open the spectrometer usb connection
+        """open the spectrometer connection
 
         Returns
         -------

From bb175dd10df8ba79e051f16b3e9ff5592fa009ac Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Thu, 30 May 2024 14:17:53 +0200
Subject: [PATCH 04/30] HDX: move to IPv4Transport [WIP]

---
 src/seabreeze/pyseabreeze/devices.py | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/devices.py b/src/seabreeze/pyseabreeze/devices.py
index 8f9e7eec..19a1cf92 100644
--- a/src/seabreeze/pyseabreeze/devices.py
+++ b/src/seabreeze/pyseabreeze/devices.py
@@ -1147,13 +1147,17 @@ class HDX(SeaBreezeDevice):
     model_name = "HDX"
 
     # communication config
-    transport = (USBTransport,)
-    usb_vendor_id = 0x2457
-    usb_product_id = 0x2003
-    usb_endpoint_map = EndPointMap(
-        ep_out=0x01, lowspeed_in=0x81, highspeed_in=0x82, highspeed_in2=0x86
-    )
-    usb_protocol = OBPProtocol
+    transport = (IPv4Transport, )
+    #usb_vendor_id = 0x2457
+    #usb_product_id = 0x2003
+    #usb_endpoint_map = EndPointMap(
+    #    ep_out=0x01, lowspeed_in=0x81, highspeed_in=0x82, highspeed_in2=0x86
+    #)
+    #usb_protocol = OBPProtocol
+
+    ipv4_address = '192.168.254.254'
+    ipv4_port = 57357
+    ipv4_protocol = OBPProtocol
 
     # spectrometer config
     dark_pixel_indices = DarkPixelIndices.from_ranges()

From aeb32c6bf8f188199cfc3f070b13aaaa231e294c Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Thu, 30 May 2024 12:28:24 +0000
Subject: [PATCH 05/30] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 src/seabreeze/pyseabreeze/api.py       | 18 ++++++++++++------
 src/seabreeze/pyseabreeze/devices.py   | 16 ++++++++--------
 src/seabreeze/pyseabreeze/transport.py | 12 +++++++-----
 3 files changed, 27 insertions(+), 19 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/api.py b/src/seabreeze/pyseabreeze/api.py
index cefe0f12..a4ca1e58 100644
--- a/src/seabreeze/pyseabreeze/api.py
+++ b/src/seabreeze/pyseabreeze/api.py
@@ -17,12 +17,12 @@
 from seabreeze.pyseabreeze.devices import SeaBreezeDevice
 from seabreeze.pyseabreeze.devices import _model_class_registry
 from seabreeze.pyseabreeze.transport import DeviceIdentity
+from seabreeze.pyseabreeze.transport import IPv4Transport
+from seabreeze.pyseabreeze.transport import IPv4TransportHandle
 from seabreeze.pyseabreeze.transport import USBTransport
 from seabreeze.pyseabreeze.transport import USBTransportDeviceInUse
 from seabreeze.pyseabreeze.transport import USBTransportError
 from seabreeze.pyseabreeze.transport import USBTransportHandle
-from seabreeze.pyseabreeze.transport import IPv4Transport
-from seabreeze.pyseabreeze.transport import IPv4TransportHandle
 from seabreeze.types import SeaBreezeAPI as _SeaBreezeAPIProtocol
 
 if TYPE_CHECKING:
@@ -37,7 +37,9 @@
 ] = weakref.WeakValueDictionary()
 
 
-def _seabreeze_device_factory(device: USBTransportHandle | IPv4TransportHandle) -> SeaBreezeDevice:
+def _seabreeze_device_factory(
+    device: USBTransportHandle | IPv4TransportHandle,
+) -> SeaBreezeDevice:
     """return existing instances instead of creating temporary ones
 
     Parameters
@@ -49,8 +51,12 @@ def _seabreeze_device_factory(device: USBTransportHandle | IPv4TransportHandle)
     dev : SeaBreezeDevice
     """
     global _seabreeze_device_instance_registry
-    if not isinstance(device, USBTransportHandle) and not isinstance(device, IPv4TransportHandle):
-        raise TypeError(f"needs to be instance of USBTransportHandle or IPv4TransportHandle and not '{type(device)}'")
+    if not isinstance(device, USBTransportHandle) and not isinstance(
+        device, IPv4TransportHandle
+    ):
+        raise TypeError(
+            f"needs to be instance of USBTransportHandle or IPv4TransportHandle and not '{type(device)}'"
+        )
     ident = device.identity
     try:
         return _seabreeze_device_instance_registry[ident]
@@ -139,7 +145,7 @@ def list_devices(self) -> list[_SeaBreezeDevice]:
                 except Exception:
                     # TODO specify expected exception
                     raise
-                #else:
+                # else:
                 #    dev.close()
             devices.append(dev)  # type: ignore
         return devices
diff --git a/src/seabreeze/pyseabreeze/devices.py b/src/seabreeze/pyseabreeze/devices.py
index 19a1cf92..cd2599f8 100644
--- a/src/seabreeze/pyseabreeze/devices.py
+++ b/src/seabreeze/pyseabreeze/devices.py
@@ -20,8 +20,8 @@
 from seabreeze.pyseabreeze.protocol import OBP2Protocol
 from seabreeze.pyseabreeze.protocol import OBPProtocol
 from seabreeze.pyseabreeze.protocol import OOIProtocol
-from seabreeze.pyseabreeze.transport import USBTransport
 from seabreeze.pyseabreeze.transport import IPv4Transport
+from seabreeze.pyseabreeze.transport import USBTransport
 from seabreeze.pyseabreeze.types import PySeaBreezeTransport
 from seabreeze.types import SeaBreezeFeatureAccessor
 
@@ -1147,15 +1147,15 @@ class HDX(SeaBreezeDevice):
     model_name = "HDX"
 
     # communication config
-    transport = (IPv4Transport, )
-    #usb_vendor_id = 0x2457
-    #usb_product_id = 0x2003
-    #usb_endpoint_map = EndPointMap(
+    transport = (IPv4Transport,)
+    # usb_vendor_id = 0x2457
+    # usb_product_id = 0x2003
+    # usb_endpoint_map = EndPointMap(
     #    ep_out=0x01, lowspeed_in=0x81, highspeed_in=0x82, highspeed_in2=0x86
-    #)
-    #usb_protocol = OBPProtocol
+    # )
+    # usb_protocol = OBPProtocol
 
-    ipv4_address = '192.168.254.254'
+    ipv4_address = "192.168.254.254"
     ipv4_port = 57357
     ipv4_protocol = OBPProtocol
 
diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index 11e7cf8b..9b7f171b 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -9,6 +9,7 @@
 import importlib
 import inspect
 import logging
+import socket
 import warnings
 from functools import partialmethod
 from typing import TYPE_CHECKING
@@ -20,8 +21,6 @@
 import usb.core
 import usb.util
 
-import socket
-
 from seabreeze.pyseabreeze.types import PySeaBreezeProtocol
 from seabreeze.pyseabreeze.types import PySeaBreezeTransport
 
@@ -367,6 +366,7 @@ def get_name_from_pyusb_backend(backend: usb.backend.IBackend) -> str | None:
         return None
     return module.__name__.split(".")[-1]
 
+
 #  ___ ____        _  _
 # |_ _|  _ \__   _| || |
 #  | || |_) \ \ / / || |_
@@ -376,7 +376,9 @@ def get_name_from_pyusb_backend(backend: usb.backend.IBackend) -> str | None:
 
 # this can and should be opaque to pyseabreeze
 class IPv4TransportHandle:
-    def __init__(self, socket: socket.socket, address: str = None, port: int = None) -> None:
+    def __init__(
+        self, socket: socket.socket, address: str = None, port: int = None
+    ) -> None:
         """encapsulation for IPv4 socket classes
 
         Parameters
@@ -486,7 +488,7 @@ def default_timeout_ms(self) -> int:
         timeout = self._device.socket.gettimeout()
         if not timeout:
             return 10000
-        return int(timeout * 1000) # type: ignore
+        return int(timeout * 1000)  # type: ignore
 
     @property
     def protocol(self) -> PySeaBreezeProtocol:
@@ -509,7 +511,7 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
         # TODO use multicast to discover potential spectrometers
         sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         # FIXME this uses the default address only
-        sock.connect(('192.168.254.254', 57357))
+        sock.connect(("192.168.254.254", 57357))
         for dev in range(1):
             yield IPv4TransportHandle(sock)
 

From 8e215a62cdb2433a1cabc953283d7b989e4af998 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Fri, 31 May 2024 11:05:38 +0200
Subject: [PATCH 06/30] IPv4: implement `register_model`

removing hard-coded default values
---
 src/seabreeze/pyseabreeze/api.py       |  3 +--
 src/seabreeze/pyseabreeze/transport.py | 29 +++++++++++++++++---------
 2 files changed, 20 insertions(+), 12 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/api.py b/src/seabreeze/pyseabreeze/api.py
index cefe0f12..162a4b9d 100644
--- a/src/seabreeze/pyseabreeze/api.py
+++ b/src/seabreeze/pyseabreeze/api.py
@@ -97,8 +97,7 @@ def add_ipv4_device_location(
         self, device_type: str, ip_address: str, port: int
     ) -> None:
         """add ipv4 device location"""
-        # IPV4Transport.register_device(device_type, ip_address, port)
-        raise NotImplementedError("ipv4 communication not implemented for pyseabreeze")
+        IPv4Transport.register_model(device_type, ipv4_address=ip_address, ipv4_port=port)
 
     def list_devices(self) -> list[_SeaBreezeDevice]:
         """returns available SeaBreezeDevices
diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index 11e7cf8b..e1946649 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -21,6 +21,7 @@
 import usb.util
 
 import socket
+import ipaddress
 
 from seabreeze.pyseabreeze.types import PySeaBreezeProtocol
 from seabreeze.pyseabreeze.types import PySeaBreezeTransport
@@ -400,23 +401,19 @@ class IPv4Transport(PySeaBreezeTransport[IPv4TransportHandle]):
     """implementation of the IPv4 socket transport interface for spectrometers"""
 
     _required_init_kwargs = (
-        "ipv4_address",
-        "ipv4_port",
         "ipv4_protocol",
     )
 
+    devices_ip_port: dict[tuple[str, int], str] = {}
+
     # add logging
     _log = logging.getLogger(__name__)
 
     def __init__(
         self,
-        ipv4_address: str,
-        ipv4_port: int,
         ipv4_protocol: type[PySeaBreezeProtocol],
     ) -> None:
         super().__init__()
-        self._address = ipv4_address
-        self._port = ipv4_port
         self._protocol_cls = ipv4_protocol
         # internal state
         self._device: IPv4TransportHandle | None = None
@@ -515,9 +512,21 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
 
     @classmethod
     def register_model(cls, model_name: str, **kwargs: Any) -> None:
-        # TODO implement e.g. IP to model mapping?
-        print(f"Trying to register {model_name} with {kwargs}")
-        pass
+        ip = kwargs.get("ipv4_address")
+        if not isinstance(ip, str):
+            raise TypeError(f"ip address {ip} not a string")
+        try:
+            ipaddress.ip_address(ip)
+        except ValueError:
+            raise ValueError(f"ip address {ip} does not represent a valid IPv4 address")
+        port = kwargs.get("ipv4_port")
+        if not isinstance(port, int):
+            raise TypeError(f"port {port} not an integer")
+        if (ip, port) in cls.devices_ip_port:
+            raise ValueError(
+                f"ip address:port {ip}:{port} already in registry"
+            )
+        cls.devices_ip_port[(ip, port)] = model_name
 
     @classmethod
     def supported_model(cls, device: IPv4TransportHandle) -> str | None:
@@ -539,7 +548,7 @@ def specialize(cls, model_name: str, **kwargs: Any) -> type[IPv4Transport]:
         # TODO check that this makes sense for the ipv4 transport
         assert set(kwargs) == set(cls._required_init_kwargs)
         # ipv4 transport register automatically on registration
-        cls.register_model(model_name, **kwargs)
+        # cls.register_model(model_name, **kwargs)
         specialized_class = type(
             f"IPv4Transport{model_name}",
             (cls,),

From 2aa2f17d2af3694e1840bc7840358bf4ac091f7b Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Fri, 31 May 2024 11:07:04 +0200
Subject: [PATCH 07/30] IPv4: list devices based on known dev locations

---
 src/seabreeze/pyseabreeze/transport.py | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index e1946649..8dd404c8 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -504,11 +504,17 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
             unique socket devices for each available spectrometer
         """
         # TODO use multicast to discover potential spectrometers
-        sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-        # FIXME this uses the default address only
-        sock.connect(('192.168.254.254', 57357))
-        for dev in range(1):
-            yield IPv4TransportHandle(sock)
+        dev_sockets = []
+        for address, model in cls.devices_ip_port.items():
+            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+            try:
+                sock.connect(address)
+            except OSError as e:
+                raise RuntimeError(f"Could not connect to {address}: {e}")
+            else:
+                dev_sockets.append(sock)
+        for dev in dev_sockets:
+            yield IPv4TransportHandle(dev)
 
     @classmethod
     def register_model(cls, model_name: str, **kwargs: Any) -> None:

From 467e66bc99f7feee911702dca143befe1b8ff584 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Fri, 31 May 2024 11:07:36 +0200
Subject: [PATCH 08/30] HDX: reinstate USB parameters

---
 src/seabreeze/pyseabreeze/devices.py | 18 ++++++++----------
 1 file changed, 8 insertions(+), 10 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/devices.py b/src/seabreeze/pyseabreeze/devices.py
index 19a1cf92..fbd4b551 100644
--- a/src/seabreeze/pyseabreeze/devices.py
+++ b/src/seabreeze/pyseabreeze/devices.py
@@ -1147,16 +1147,14 @@ class HDX(SeaBreezeDevice):
     model_name = "HDX"
 
     # communication config
-    transport = (IPv4Transport, )
-    #usb_vendor_id = 0x2457
-    #usb_product_id = 0x2003
-    #usb_endpoint_map = EndPointMap(
-    #    ep_out=0x01, lowspeed_in=0x81, highspeed_in=0x82, highspeed_in2=0x86
-    #)
-    #usb_protocol = OBPProtocol
-
-    ipv4_address = '192.168.254.254'
-    ipv4_port = 57357
+    transport = (IPv4Transport, USBTransport, )
+    usb_vendor_id = 0x2457
+    usb_product_id = 0x2003
+    usb_endpoint_map = EndPointMap(
+        ep_out=0x01, lowspeed_in=0x81, highspeed_in=0x82, highspeed_in2=0x86
+    )
+    usb_protocol = OBPProtocol
+
     ipv4_protocol = OBPProtocol
 
     # spectrometer config

From e7b0be3b90078f6d6f2103a99dbf927ce402c9c3 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Fri, 31 May 2024 11:08:21 +0200
Subject: [PATCH 09/30] features: implement OBP multicast

according to "Firmware and Advanced Communications: OCEAN HDX Firmware"
---
 src/seabreeze/pyseabreeze/devices.py          |  1 +
 .../pyseabreeze/features/multicast.py         | 41 ++++++++++++++++++-
 src/seabreeze/pyseabreeze/protocol.py         |  4 ++
 3 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/src/seabreeze/pyseabreeze/devices.py b/src/seabreeze/pyseabreeze/devices.py
index fbd4b551..f447d6da 100644
--- a/src/seabreeze/pyseabreeze/devices.py
+++ b/src/seabreeze/pyseabreeze/devices.py
@@ -1174,6 +1174,7 @@ class HDX(SeaBreezeDevice):
         sbf.spectrometer.SeaBreezeSpectrometerFeatureHDX,
         sbf.rawusb.SeaBreezeRawUSBBusAccessFeature,
         sbf.nonlinearity.NonlinearityCoefficientsFeatureOBP,
+        sbf.multicast.SeaBreezeMulticastFeatureOBP,
     )
 
 
diff --git a/src/seabreeze/pyseabreeze/features/multicast.py b/src/seabreeze/pyseabreeze/features/multicast.py
index b10ef3bb..9f290fd0 100644
--- a/src/seabreeze/pyseabreeze/features/multicast.py
+++ b/src/seabreeze/pyseabreeze/features/multicast.py
@@ -1,5 +1,6 @@
+import struct
 from seabreeze.pyseabreeze.features._base import SeaBreezeFeature
-
+from seabreeze.pyseabreeze.protocol import OBPProtocol
 
 # Definition
 # ==========
@@ -16,3 +17,41 @@ def set_multicast_enable_state(
         self, interface_index: int, enable_state: bool
     ) -> None:
         raise NotImplementedError("implement in derived class")
+
+    def get_multicast_group_address(self, interface_index: int) -> tuple[int, int , int, int]:
+        raise NotImplementedError("implement in derived class")
+
+    def get_multicast_group_port(self, interface_index: int) -> int:
+        raise NotImplementedError("implement in derived class")
+
+    def get_multicast_ttl(self, interface_index: int) -> int:
+        raise NotImplementedError("implement in derived class")
+
+
+# OBP implementation
+# ==================
+#
+class SeaBreezeMulticastFeatureOBP(SeaBreezeMulticastFeature):
+    _required_protocol_cls = OBPProtocol
+
+    def get_multicast_enable_state(self, interface_index: int) -> bool:
+        ret = self.protocol.query(0x00000A80, int(interface_index))
+        return bool(struct.unpack("<B", ret))
+
+    def set_multicast_enable_state(
+        self, interface_index: int, enable_state: bool
+    ) -> None:
+        raise NotImplementedError("missing from HDX FW documentation")
+
+    def get_multicast_group_address(self, interface_index: int) -> tuple[int, int, int, int]:
+        ret = self.protocol.query(0x00000A81, int(interface_index))
+        ip = struct.unpack("<BBBB", ret)
+        return ip
+
+    def get_multicast_group_port(self, interface_index: int) -> int:
+        ret = self.protocol.query(0x00000A82, int(interface_index))
+        return struct.unpack("<H", ret)
+
+    def get_multicast_ttl(self, interface_index: int) -> int:
+        ret = self.protocol.query(0x00000A83, int(interface_index))
+        return struct.unpack("<B", ret)
diff --git a/src/seabreeze/pyseabreeze/protocol.py b/src/seabreeze/pyseabreeze/protocol.py
index 2004c9d5..f4488570 100644
--- a/src/seabreeze/pyseabreeze/protocol.py
+++ b/src/seabreeze/pyseabreeze/protocol.py
@@ -229,6 +229,10 @@ class OBPProtocol(PySeaBreezeProtocol):
             0x00420004: "",  # GET_TE_TEMPERATURE
             0x00420010: "<B",  # SET_TE_ENABLE
             0x00420011: "<f",  # SET_TE_SETPOINT
+            0x00000A80: "<B", # GET_MC_ENABLED
+            0x00000A81: "<B", # GET_MC_GROUP_ADDR
+            0x00000A82: "<B", # GET_MC_GROUP_PORT
+            0x00000A83: "<B", # GET_MC_TTL
         }.items()
     }  # add more here if you implement new features
 

From d9e85e50e233b15bab9c75871e97b467ed671a8a Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Fri, 31 May 2024 09:11:26 +0000
Subject: [PATCH 10/30] [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci
---
 src/seabreeze/pyseabreeze/api.py                |  4 +++-
 src/seabreeze/pyseabreeze/devices.py            |  5 ++++-
 src/seabreeze/pyseabreeze/features/multicast.py | 10 ++++++++--
 src/seabreeze/pyseabreeze/protocol.py           |  8 ++++----
 src/seabreeze/pyseabreeze/transport.py          | 12 +++---------
 5 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/api.py b/src/seabreeze/pyseabreeze/api.py
index ca1a7dc7..51c7dcff 100644
--- a/src/seabreeze/pyseabreeze/api.py
+++ b/src/seabreeze/pyseabreeze/api.py
@@ -103,7 +103,9 @@ def add_ipv4_device_location(
         self, device_type: str, ip_address: str, port: int
     ) -> None:
         """add ipv4 device location"""
-        IPv4Transport.register_model(device_type, ipv4_address=ip_address, ipv4_port=port)
+        IPv4Transport.register_model(
+            device_type, ipv4_address=ip_address, ipv4_port=port
+        )
 
     def list_devices(self) -> list[_SeaBreezeDevice]:
         """returns available SeaBreezeDevices
diff --git a/src/seabreeze/pyseabreeze/devices.py b/src/seabreeze/pyseabreeze/devices.py
index db92d7c2..04291ffa 100644
--- a/src/seabreeze/pyseabreeze/devices.py
+++ b/src/seabreeze/pyseabreeze/devices.py
@@ -1147,7 +1147,10 @@ class HDX(SeaBreezeDevice):
     model_name = "HDX"
 
     # communication config
-    transport = (IPv4Transport, USBTransport, )
+    transport = (
+        IPv4Transport,
+        USBTransport,
+    )
     usb_vendor_id = 0x2457
     usb_product_id = 0x2003
     usb_endpoint_map = EndPointMap(
diff --git a/src/seabreeze/pyseabreeze/features/multicast.py b/src/seabreeze/pyseabreeze/features/multicast.py
index 9f290fd0..551605cd 100644
--- a/src/seabreeze/pyseabreeze/features/multicast.py
+++ b/src/seabreeze/pyseabreeze/features/multicast.py
@@ -1,7 +1,9 @@
 import struct
+
 from seabreeze.pyseabreeze.features._base import SeaBreezeFeature
 from seabreeze.pyseabreeze.protocol import OBPProtocol
 
+
 # Definition
 # ==========
 #
@@ -18,7 +20,9 @@ def set_multicast_enable_state(
     ) -> None:
         raise NotImplementedError("implement in derived class")
 
-    def get_multicast_group_address(self, interface_index: int) -> tuple[int, int , int, int]:
+    def get_multicast_group_address(
+        self, interface_index: int
+    ) -> tuple[int, int, int, int]:
         raise NotImplementedError("implement in derived class")
 
     def get_multicast_group_port(self, interface_index: int) -> int:
@@ -43,7 +47,9 @@ def set_multicast_enable_state(
     ) -> None:
         raise NotImplementedError("missing from HDX FW documentation")
 
-    def get_multicast_group_address(self, interface_index: int) -> tuple[int, int, int, int]:
+    def get_multicast_group_address(
+        self, interface_index: int
+    ) -> tuple[int, int, int, int]:
         ret = self.protocol.query(0x00000A81, int(interface_index))
         ip = struct.unpack("<BBBB", ret)
         return ip
diff --git a/src/seabreeze/pyseabreeze/protocol.py b/src/seabreeze/pyseabreeze/protocol.py
index f4488570..99961f3e 100644
--- a/src/seabreeze/pyseabreeze/protocol.py
+++ b/src/seabreeze/pyseabreeze/protocol.py
@@ -229,10 +229,10 @@ class OBPProtocol(PySeaBreezeProtocol):
             0x00420004: "",  # GET_TE_TEMPERATURE
             0x00420010: "<B",  # SET_TE_ENABLE
             0x00420011: "<f",  # SET_TE_SETPOINT
-            0x00000A80: "<B", # GET_MC_ENABLED
-            0x00000A81: "<B", # GET_MC_GROUP_ADDR
-            0x00000A82: "<B", # GET_MC_GROUP_PORT
-            0x00000A83: "<B", # GET_MC_TTL
+            0x00000A80: "<B",  # GET_MC_ENABLED
+            0x00000A81: "<B",  # GET_MC_GROUP_ADDR
+            0x00000A82: "<B",  # GET_MC_GROUP_PORT
+            0x00000A83: "<B",  # GET_MC_TTL
         }.items()
     }  # add more here if you implement new features
 
diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index f6eed8b6..95d28a7a 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -8,6 +8,7 @@
 
 import importlib
 import inspect
+import ipaddress
 import logging
 import socket
 import warnings
@@ -21,9 +22,6 @@
 import usb.core
 import usb.util
 
-import socket
-import ipaddress
-
 from seabreeze.pyseabreeze.types import PySeaBreezeProtocol
 from seabreeze.pyseabreeze.types import PySeaBreezeTransport
 
@@ -404,9 +402,7 @@ def __del__(self) -> None:
 class IPv4Transport(PySeaBreezeTransport[IPv4TransportHandle]):
     """implementation of the IPv4 socket transport interface for spectrometers"""
 
-    _required_init_kwargs = (
-        "ipv4_protocol",
-    )
+    _required_init_kwargs = ("ipv4_protocol",)
 
     devices_ip_port: dict[tuple[str, int], str] = {}
 
@@ -533,9 +529,7 @@ def register_model(cls, model_name: str, **kwargs: Any) -> None:
         if not isinstance(port, int):
             raise TypeError(f"port {port} not an integer")
         if (ip, port) in cls.devices_ip_port:
-            raise ValueError(
-                f"ip address:port {ip}:{port} already in registry"
-            )
+            raise ValueError(f"ip address:port {ip}:{port} already in registry")
         cls.devices_ip_port[(ip, port)] = model_name
 
     @classmethod

From b754d41c3bd5ff8a3f6fbbda9bea779695911fa3 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Fri, 31 May 2024 13:16:55 +0200
Subject: [PATCH 11/30] ipv4transport: add multicast discovery listing dev

---
 src/seabreeze/pyseabreeze/transport.py | 51 ++++++++++++++++++++++----
 1 file changed, 43 insertions(+), 8 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index f6eed8b6..1397aee2 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -9,7 +9,6 @@
 import importlib
 import inspect
 import logging
-import socket
 import warnings
 from functools import partialmethod
 from typing import TYPE_CHECKING
@@ -17,15 +16,16 @@
 from typing import Iterable
 from typing import Tuple
 
+import socket
+import ipaddress
+
 import usb.backend
 import usb.core
 import usb.util
 
-import socket
-import ipaddress
-
 from seabreeze.pyseabreeze.types import PySeaBreezeProtocol
 from seabreeze.pyseabreeze.types import PySeaBreezeTransport
+from seabreeze.pyseabreeze.protocol import OBPProtocol
 
 if TYPE_CHECKING:
     from seabreeze.pyseabreeze.devices import EndPointMap
@@ -507,9 +507,44 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
         devices : IPv4TransportHandle
             unique socket devices for each available spectrometer
         """
-        # TODO use multicast to discover potential spectrometers
         dev_sockets = []
-        for address, model in cls.devices_ip_port.items():
+
+        # Use multicast to discover potential spectrometers. Requires a network
+        # adapter to be specified.
+        network_adapter = kwargs.get("network_adapter", None)
+        if network_adapter:
+            multicast_group = (
+                kwargs.get("multicast_group", '239.239.239.239'),
+                kwargs.get("multicast_port", 57357),
+            )  # default values for HDX devices
+            # Create the datagram (UDP) socket
+            sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+            # Set a timeout so the socket does not block
+            # indefinitely when trying to receive data.
+            sock.settimeout(kwargs.get("multicast_timeout", 2))
+            sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_IF, socket.inet_aton(network_adapter))
+            handle = IPv4TransportHandle(sock)
+            transport = IPv4Transport(handle)
+            protocol = OBPProtocol(transport)
+            msg_type = 0x00000100  # GET_SERIAL
+            data = protocol.msgs[msg_type](*())
+            message = protocol._construct_outgoing_message(
+                msg_type, data, request_ack=True,
+            )
+            sock.sendto(message, multicast_group)
+            print('Waiting to receive multicast response(s)')
+            while True:
+                try:
+                    data = bytearray(90)
+                    nbytes, server = sock.recvfrom_into(data)
+                except socket.timeout:
+                    break
+                else:
+                    serial = protocol._extract_message_data(data[:nbytes])
+                    cls.register_model(model_name=serial, ipv4_address=server[0], ipv4_port=server[1])
+
+        # connect to discovered and registered devices
+        for address in cls.devices_ip_port:
             sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
             try:
                 sock.connect(address)
@@ -517,8 +552,8 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
                 raise RuntimeError(f"Could not connect to {address}: {e}")
             else:
                 dev_sockets.append(sock)
-        for dev in dev_sockets:
-            yield IPv4TransportHandle(dev)
+        for sock in dev_sockets:
+            yield IPv4TransportHandle(sock)
 
     @classmethod
     def register_model(cls, model_name: str, **kwargs: Any) -> None:

From 3df7d493be4da8ba3fa31869c1ed3552bd65ddbc Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Fri, 31 May 2024 13:52:50 +0200
Subject: [PATCH 12/30] IPv4TransportHandle: get port+address from socket

---
 src/seabreeze/pyseabreeze/transport.py | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index 1397aee2..0700d71b 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -380,7 +380,7 @@ def get_name_from_pyusb_backend(backend: usb.backend.IBackend) -> str | None:
 # this can and should be opaque to pyseabreeze
 class IPv4TransportHandle:
     def __init__(
-        self, socket: socket.socket, address: str = None, port: int = None
+        self, sock: socket.socket
     ) -> None:
         """encapsulation for IPv4 socket classes
 
@@ -388,8 +388,12 @@ def __init__(
         ----------
 
         """
-        self.socket: socket.socket = socket
+        self.socket: socket.socket = sock
         # TODO check if socket is connected and get address via socket (socket.getpeername())
+        try:
+            address, port = sock.getpeername()
+        except OSError:
+            address, port = None, None
         self.identity: tuple[str, int] = (address, port)
 
     def close(self) -> None:

From a5eed7c9e7f436fdf7d95d495b749c1023853f05 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Fri, 31 May 2024 13:53:06 +0200
Subject: [PATCH 13/30] IPv4Transport: fix type error

---
 src/seabreeze/pyseabreeze/transport.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index 0700d71b..a60f5b15 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -527,8 +527,7 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
             # indefinitely when trying to receive data.
             sock.settimeout(kwargs.get("multicast_timeout", 2))
             sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_IF, socket.inet_aton(network_adapter))
-            handle = IPv4TransportHandle(sock)
-            transport = IPv4Transport(handle)
+            transport = IPv4Transport(OBPProtocol)
             protocol = OBPProtocol(transport)
             msg_type = 0x00000100  # GET_SERIAL
             data = protocol.msgs[msg_type](*())

From abd378b0f719b667aaed50101e15ad9b812b75ba Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Fri, 31 May 2024 14:27:37 +0200
Subject: [PATCH 14/30] isort, black, type fixes for mypy

---
 src/seabreeze/pyseabreeze/api.py              |  4 +-
 src/seabreeze/pyseabreeze/devices.py          |  5 ++-
 .../pyseabreeze/features/multicast.py         | 13 +++---
 src/seabreeze/pyseabreeze/protocol.py         |  8 ++--
 src/seabreeze/pyseabreeze/transport.py        | 42 ++++++++++---------
 5 files changed, 41 insertions(+), 31 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/api.py b/src/seabreeze/pyseabreeze/api.py
index ca1a7dc7..51c7dcff 100644
--- a/src/seabreeze/pyseabreeze/api.py
+++ b/src/seabreeze/pyseabreeze/api.py
@@ -103,7 +103,9 @@ def add_ipv4_device_location(
         self, device_type: str, ip_address: str, port: int
     ) -> None:
         """add ipv4 device location"""
-        IPv4Transport.register_model(device_type, ipv4_address=ip_address, ipv4_port=port)
+        IPv4Transport.register_model(
+            device_type, ipv4_address=ip_address, ipv4_port=port
+        )
 
     def list_devices(self) -> list[_SeaBreezeDevice]:
         """returns available SeaBreezeDevices
diff --git a/src/seabreeze/pyseabreeze/devices.py b/src/seabreeze/pyseabreeze/devices.py
index db92d7c2..04291ffa 100644
--- a/src/seabreeze/pyseabreeze/devices.py
+++ b/src/seabreeze/pyseabreeze/devices.py
@@ -1147,7 +1147,10 @@ class HDX(SeaBreezeDevice):
     model_name = "HDX"
 
     # communication config
-    transport = (IPv4Transport, USBTransport, )
+    transport = (
+        IPv4Transport,
+        USBTransport,
+    )
     usb_vendor_id = 0x2457
     usb_product_id = 0x2003
     usb_endpoint_map = EndPointMap(
diff --git a/src/seabreeze/pyseabreeze/features/multicast.py b/src/seabreeze/pyseabreeze/features/multicast.py
index 9f290fd0..19faa0b1 100644
--- a/src/seabreeze/pyseabreeze/features/multicast.py
+++ b/src/seabreeze/pyseabreeze/features/multicast.py
@@ -1,7 +1,10 @@
 import struct
+from typing import List
+
 from seabreeze.pyseabreeze.features._base import SeaBreezeFeature
 from seabreeze.pyseabreeze.protocol import OBPProtocol
 
+
 # Definition
 # ==========
 #
@@ -18,7 +21,7 @@ def set_multicast_enable_state(
     ) -> None:
         raise NotImplementedError("implement in derived class")
 
-    def get_multicast_group_address(self, interface_index: int) -> tuple[int, int , int, int]:
+    def get_multicast_group_address(self, interface_index: int) -> List[int]:
         raise NotImplementedError("implement in derived class")
 
     def get_multicast_group_port(self, interface_index: int) -> int:
@@ -43,15 +46,15 @@ def set_multicast_enable_state(
     ) -> None:
         raise NotImplementedError("missing from HDX FW documentation")
 
-    def get_multicast_group_address(self, interface_index: int) -> tuple[int, int, int, int]:
+    def get_multicast_group_address(self, interface_index: int) -> List[int]:
         ret = self.protocol.query(0x00000A81, int(interface_index))
         ip = struct.unpack("<BBBB", ret)
-        return ip
+        return [int(ip[0]), int(ip[1]), int(ip[2]), int(ip[3])]
 
     def get_multicast_group_port(self, interface_index: int) -> int:
         ret = self.protocol.query(0x00000A82, int(interface_index))
-        return struct.unpack("<H", ret)
+        return int(struct.unpack("<H", ret)[0])
 
     def get_multicast_ttl(self, interface_index: int) -> int:
         ret = self.protocol.query(0x00000A83, int(interface_index))
-        return struct.unpack("<B", ret)
+        return int(struct.unpack("<B", ret)[0])
diff --git a/src/seabreeze/pyseabreeze/protocol.py b/src/seabreeze/pyseabreeze/protocol.py
index f4488570..99961f3e 100644
--- a/src/seabreeze/pyseabreeze/protocol.py
+++ b/src/seabreeze/pyseabreeze/protocol.py
@@ -229,10 +229,10 @@ class OBPProtocol(PySeaBreezeProtocol):
             0x00420004: "",  # GET_TE_TEMPERATURE
             0x00420010: "<B",  # SET_TE_ENABLE
             0x00420011: "<f",  # SET_TE_SETPOINT
-            0x00000A80: "<B", # GET_MC_ENABLED
-            0x00000A81: "<B", # GET_MC_GROUP_ADDR
-            0x00000A82: "<B", # GET_MC_GROUP_PORT
-            0x00000A83: "<B", # GET_MC_TTL
+            0x00000A80: "<B",  # GET_MC_ENABLED
+            0x00000A81: "<B",  # GET_MC_GROUP_ADDR
+            0x00000A82: "<B",  # GET_MC_GROUP_PORT
+            0x00000A83: "<B",  # GET_MC_TTL
         }.items()
     }  # add more here if you implement new features
 
diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index a60f5b15..9314f36f 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -8,7 +8,9 @@
 
 import importlib
 import inspect
+import ipaddress
 import logging
+import socket
 import warnings
 from functools import partialmethod
 from typing import TYPE_CHECKING
@@ -16,16 +18,13 @@
 from typing import Iterable
 from typing import Tuple
 
-import socket
-import ipaddress
-
 import usb.backend
 import usb.core
 import usb.util
 
+from seabreeze.pyseabreeze.protocol import OBPProtocol
 from seabreeze.pyseabreeze.types import PySeaBreezeProtocol
 from seabreeze.pyseabreeze.types import PySeaBreezeTransport
-from seabreeze.pyseabreeze.protocol import OBPProtocol
 
 if TYPE_CHECKING:
     from seabreeze.pyseabreeze.devices import EndPointMap
@@ -379,9 +378,7 @@ def get_name_from_pyusb_backend(backend: usb.backend.IBackend) -> str | None:
 
 # this can and should be opaque to pyseabreeze
 class IPv4TransportHandle:
-    def __init__(
-        self, sock: socket.socket
-    ) -> None:
+    def __init__(self, sock: socket.socket) -> None:
         """encapsulation for IPv4 socket classes
 
         Parameters
@@ -402,15 +399,12 @@ def close(self) -> None:
 
     def __del__(self) -> None:
         self.close()
-        self.socket = None
 
 
 class IPv4Transport(PySeaBreezeTransport[IPv4TransportHandle]):
     """implementation of the IPv4 socket transport interface for spectrometers"""
 
-    _required_init_kwargs = (
-        "ipv4_protocol",
-    )
+    _required_init_kwargs = ("ipv4_protocol",)
 
     devices_ip_port: dict[tuple[str, int], str] = {}
 
@@ -491,7 +485,7 @@ def default_timeout_ms(self) -> int:
         timeout = self._device.socket.gettimeout()
         if not timeout:
             return 10000
-        return int(timeout * 1000)  # type: ignore
+        return int(timeout * 1000)
 
     @property
     def protocol(self) -> PySeaBreezeProtocol:
@@ -518,7 +512,7 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
         network_adapter = kwargs.get("network_adapter", None)
         if network_adapter:
             multicast_group = (
-                kwargs.get("multicast_group", '239.239.239.239'),
+                kwargs.get("multicast_group", "239.239.239.239"),
                 kwargs.get("multicast_port", 57357),
             )  # default values for HDX devices
             # Create the datagram (UDP) socket
@@ -526,16 +520,22 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
             # Set a timeout so the socket does not block
             # indefinitely when trying to receive data.
             sock.settimeout(kwargs.get("multicast_timeout", 2))
-            sock.setsockopt(socket.IPPROTO_IP, socket.IP_MULTICAST_IF, socket.inet_aton(network_adapter))
+            sock.setsockopt(
+                socket.IPPROTO_IP,
+                socket.IP_MULTICAST_IF,
+                socket.inet_aton(network_adapter),
+            )
             transport = IPv4Transport(OBPProtocol)
             protocol = OBPProtocol(transport)
             msg_type = 0x00000100  # GET_SERIAL
             data = protocol.msgs[msg_type](*())
             message = protocol._construct_outgoing_message(
-                msg_type, data, request_ack=True,
+                msg_type,
+                data,
+                request_ack=True,
             )
             sock.sendto(message, multicast_group)
-            print('Waiting to receive multicast response(s)')
+            print("Waiting to receive multicast response(s)")
             while True:
                 try:
                     data = bytearray(90)
@@ -544,7 +544,11 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
                     break
                 else:
                     serial = protocol._extract_message_data(data[:nbytes])
-                    cls.register_model(model_name=serial, ipv4_address=server[0], ipv4_port=server[1])
+                    cls.register_model(
+                        model_name=serial.decode(),
+                        ipv4_address=server[0],
+                        ipv4_port=server[1],
+                    )
 
         # connect to discovered and registered devices
         for address in cls.devices_ip_port:
@@ -571,9 +575,7 @@ def register_model(cls, model_name: str, **kwargs: Any) -> None:
         if not isinstance(port, int):
             raise TypeError(f"port {port} not an integer")
         if (ip, port) in cls.devices_ip_port:
-            raise ValueError(
-                f"ip address:port {ip}:{port} already in registry"
-            )
+            raise ValueError(f"ip address:port {ip}:{port} already in registry")
         cls.devices_ip_port[(ip, port)] = model_name
 
     @classmethod

From 561ee33dca872cf74df970e104b6f2c8877a76b1 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Fri, 31 May 2024 17:06:40 +0200
Subject: [PATCH 15/30] multicast: request product ID instead for serial

allows to match to correct model via known USB parameters
---
 src/seabreeze/pyseabreeze/protocol.py  |  3 +++
 src/seabreeze/pyseabreeze/transport.py | 13 ++++++++++---
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/protocol.py b/src/seabreeze/pyseabreeze/protocol.py
index 99961f3e..69a2a981 100644
--- a/src/seabreeze/pyseabreeze/protocol.py
+++ b/src/seabreeze/pyseabreeze/protocol.py
@@ -233,6 +233,9 @@ class OBPProtocol(PySeaBreezeProtocol):
             0x00000A81: "<B",  # GET_MC_GROUP_ADDR
             0x00000A82: "<B",  # GET_MC_GROUP_PORT
             0x00000A83: "<B",  # GET_MC_TTL
+            0xE11: "",  # GET_DEV_STR
+            0xE00: "",  # GET_VID
+            0xE01: "",  # GET_PID
         }.items()
     }  # add more here if you implement new features
 
diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index 9314f36f..e67f2d54 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -11,6 +11,7 @@
 import ipaddress
 import logging
 import socket
+import struct
 import warnings
 from functools import partialmethod
 from typing import TYPE_CHECKING
@@ -525,9 +526,11 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
                 socket.IP_MULTICAST_IF,
                 socket.inet_aton(network_adapter),
             )
+            # prepare a message requesting all devices in the multicast group
+            # to send their (USB) product id
             transport = IPv4Transport(OBPProtocol)
             protocol = OBPProtocol(transport)
-            msg_type = 0x00000100  # GET_SERIAL
+            msg_type = 0xE01  # Product ID
             data = protocol.msgs[msg_type](*())
             message = protocol._construct_outgoing_message(
                 msg_type,
@@ -543,9 +546,13 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
                 except socket.timeout:
                     break
                 else:
-                    serial = protocol._extract_message_data(data[:nbytes])
+                    pid_raw = protocol._extract_message_data(data[:nbytes])
+                    pid = int(struct.unpack("<H", pid_raw)[0])
+                    # use known product ids of the USB transport to look up the model name
+                    vid = 0x2457  # Ocean vendor ID
+                    model = USBTransport.vendor_product_ids[(vid, pid)]
                     cls.register_model(
-                        model_name=serial.decode(),
+                        model_name=model,
                         ipv4_address=server[0],
                         ipv4_port=server[1],
                     )

From d0156df83a5a3c470ec1df29ac6ca6a22b29b99e Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Fri, 31 May 2024 17:07:27 +0200
Subject: [PATCH 16/30] ipv4transport: implement `supported_model`

---
 src/seabreeze/pyseabreeze/transport.py | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index e67f2d54..c8a731e3 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -593,12 +593,9 @@ def supported_model(cls, device: IPv4TransportHandle) -> str | None:
         ----------
         device : IPv4TransportHandle
         """
-        # TODO implement this method
         if not isinstance(device, IPv4TransportHandle):
             return None
-        # noinspection PyUnresolvedReferences
-        # FIXME return something other then a hard-coded string
-        return "HDX"
+        return cls.devices_ip_port[device.identity]
 
     @classmethod
     def specialize(cls, model_name: str, **kwargs: Any) -> type[IPv4Transport]:
@@ -615,7 +612,7 @@ def specialize(cls, model_name: str, **kwargs: Any) -> type[IPv4Transport]:
 
     @classmethod
     def initialize(cls, **_kwargs: Any) -> None:
-        # TODO implement socket resent (close/open?)
+        # TODO implement socket reset? (close/open?)
         pass
 
     @classmethod

From 2d6732b06cd5e4ec2200cff623c977cd14964437 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Mon, 3 Jun 2024 10:15:30 +0200
Subject: [PATCH 17/30] ipv4transport: send multicast on INADDR_ANY

if no `network_adapter` argument has been provided. This will send the
multicast request on an "appropriate" interface, usually the one with
the highest metric.
---
 src/seabreeze/pyseabreeze/transport.py | 106 ++++++++++++++-----------
 1 file changed, 59 insertions(+), 47 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index c8a731e3..ca88ae19 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -508,54 +508,66 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
         """
         dev_sockets = []
 
-        # Use multicast to discover potential spectrometers. Requires a network
-        # adapter to be specified.
+        # Use multicast to discover potential spectrometers. If no network
+        # adapter was specified use INADDR_ANY: an appropriate interface is
+        # chosen by the system (see ip(7)). This is usually the interface with
+        # the highest metric.
         network_adapter = kwargs.get("network_adapter", None)
-        if network_adapter:
-            multicast_group = (
-                kwargs.get("multicast_group", "239.239.239.239"),
-                kwargs.get("multicast_port", 57357),
-            )  # default values for HDX devices
-            # Create the datagram (UDP) socket
-            sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
-            # Set a timeout so the socket does not block
-            # indefinitely when trying to receive data.
-            sock.settimeout(kwargs.get("multicast_timeout", 2))
-            sock.setsockopt(
-                socket.IPPROTO_IP,
-                socket.IP_MULTICAST_IF,
-                socket.inet_aton(network_adapter),
-            )
-            # prepare a message requesting all devices in the multicast group
-            # to send their (USB) product id
-            transport = IPv4Transport(OBPProtocol)
-            protocol = OBPProtocol(transport)
-            msg_type = 0xE01  # Product ID
-            data = protocol.msgs[msg_type](*())
-            message = protocol._construct_outgoing_message(
-                msg_type,
-                data,
-                request_ack=True,
-            )
-            sock.sendto(message, multicast_group)
-            print("Waiting to receive multicast response(s)")
-            while True:
-                try:
-                    data = bytearray(90)
-                    nbytes, server = sock.recvfrom_into(data)
-                except socket.timeout:
-                    break
-                else:
-                    pid_raw = protocol._extract_message_data(data[:nbytes])
-                    pid = int(struct.unpack("<H", pid_raw)[0])
-                    # use known product ids of the USB transport to look up the model name
-                    vid = 0x2457  # Ocean vendor ID
-                    model = USBTransport.vendor_product_ids[(vid, pid)]
-                    cls.register_model(
-                        model_name=model,
-                        ipv4_address=server[0],
-                        ipv4_port=server[1],
-                    )
+        # default values for multicast on HDX devices
+        multicast_group = kwargs.get("multicast_group", "239.239.239.239")
+        multicast_port = kwargs.get("multicast_port", 57357)
+        # Create the datagram (UDP) socket
+        sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        # allow other sockets to bind this port too
+        sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+        # Set a timeout so the socket does not block
+        # indefinitely when trying to receive data.
+        sock.settimeout(kwargs.get("multicast_timeout", 2))
+        sock.setsockopt(
+            socket.IPPROTO_IP,
+            socket.IP_MULTICAST_IF,
+            socket.inet_aton(network_adapter) if network_adapter else socket.INADDR_ANY,
+        )
+        mreq = struct.pack(
+            "4sl" if not network_adapter else "4s4s",
+            socket.inet_aton(multicast_group),
+            (
+                socket.INADDR_ANY
+                if not network_adapter
+                else socket.inet_aton(network_adapter)
+            ),
+        )
+        sock.setsockopt(socket.IPPROTO_IP, socket.IP_ADD_MEMBERSHIP, mreq)
+        # prepare a message requesting all devices in the multicast group
+        # to send their (USB) product id
+        transport = IPv4Transport(OBPProtocol)
+        protocol = OBPProtocol(transport)
+        msg_type = 0xE01  # Product ID
+        data = protocol.msgs[msg_type](*())
+        message = protocol._construct_outgoing_message(
+            msg_type,
+            data,
+            request_ack=True,
+        )
+        sock.sendto(message, (multicast_group, multicast_port))
+        print("Waiting to receive multicast response(s)")
+        while True:
+            try:
+                data = bytearray(90)
+                nbytes, server = sock.recvfrom_into(data)
+            except socket.timeout:
+                break
+            else:
+                pid_raw = protocol._extract_message_data(data[:nbytes])
+                pid = int(struct.unpack("<H", pid_raw)[0])
+                # use known product ids of the USB transport to look up the model name
+                vid = 0x2457  # Ocean vendor ID
+                model = USBTransport.vendor_product_ids[(vid, pid)]
+                cls.register_model(
+                    model_name=model,
+                    ipv4_address=server[0],
+                    ipv4_port=server[1],
+                )
 
         # connect to discovered and registered devices
         for address in cls.devices_ip_port:

From 9e1c841ee17f64bb9154022437a89fab03057f46 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Mon, 3 Jun 2024 10:17:20 +0200
Subject: [PATCH 18/30] ipv4transport: move list initialization

---
 src/seabreeze/pyseabreeze/transport.py | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index ca88ae19..e22d4411 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -506,8 +506,6 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
         devices : IPv4TransportHandle
             unique socket devices for each available spectrometer
         """
-        dev_sockets = []
-
         # Use multicast to discover potential spectrometers. If no network
         # adapter was specified use INADDR_ANY: an appropriate interface is
         # chosen by the system (see ip(7)). This is usually the interface with
@@ -570,6 +568,7 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
                 )
 
         # connect to discovered and registered devices
+        dev_sockets = []
         for address in cls.devices_ip_port:
             sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
             try:

From 1105993aae4c54acb484efd2ce8a15f182f2bdee Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hperrey@users.noreply.github.com>
Date: Mon, 3 Jun 2024 10:21:17 +0200
Subject: [PATCH 19/30] Update src/seabreeze/pyseabreeze/api.py

improve style

Co-authored-by: Andreas Poehlmann <ap--@users.noreply.github.com>
---
 src/seabreeze/pyseabreeze/api.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/api.py b/src/seabreeze/pyseabreeze/api.py
index 51c7dcff..942853b9 100644
--- a/src/seabreeze/pyseabreeze/api.py
+++ b/src/seabreeze/pyseabreeze/api.py
@@ -51,9 +51,7 @@ def _seabreeze_device_factory(
     dev : SeaBreezeDevice
     """
     global _seabreeze_device_instance_registry
-    if not isinstance(device, USBTransportHandle) and not isinstance(
-        device, IPv4TransportHandle
-    ):
+    if not isinstance(device, (USBTransportHandle, IPv4TransportHandle)):
         raise TypeError(
             f"needs to be instance of USBTransportHandle or IPv4TransportHandle and not '{type(device)}'"
         )

From 7e6ef0f8a717d6efed229fdd3629d15c7542a42f Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Mon, 3 Jun 2024 10:48:01 +0200
Subject: [PATCH 20/30] ipv4transport: remove print statement

---
 src/seabreeze/pyseabreeze/transport.py | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index e22d4411..3d43f3e4 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -548,7 +548,6 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
             request_ack=True,
         )
         sock.sendto(message, (multicast_group, multicast_port))
-        print("Waiting to receive multicast response(s)")
         while True:
             try:
                 data = bytearray(90)

From a21e3968f4907cf820e74d9f12c326e1de7fc93d Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Mon, 3 Jun 2024 10:48:20 +0200
Subject: [PATCH 21/30] ipv4transport: remove unnecessary argument

---
 src/seabreeze/pyseabreeze/transport.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index 3d43f3e4..97711437 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -541,7 +541,7 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
         transport = IPv4Transport(OBPProtocol)
         protocol = OBPProtocol(transport)
         msg_type = 0xE01  # Product ID
-        data = protocol.msgs[msg_type](*())
+        data = protocol.msgs[msg_type]()
         message = protocol._construct_outgoing_message(
             msg_type,
             data,

From eabcc1c9d42381d8759c939bd107632bef636dfd Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Mon, 3 Jun 2024 10:48:42 +0200
Subject: [PATCH 22/30] ipv4transport: remove TODOs

---
 src/seabreeze/pyseabreeze/transport.py | 2 --
 1 file changed, 2 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index 97711437..7f0a52c5 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -622,10 +622,8 @@ def specialize(cls, model_name: str, **kwargs: Any) -> type[IPv4Transport]:
 
     @classmethod
     def initialize(cls, **_kwargs: Any) -> None:
-        # TODO implement socket reset? (close/open?)
         pass
 
     @classmethod
     def shutdown(cls, **_kwargs: Any) -> None:
-        # TODO implement
         pass

From 88afbe1744ba2549e7dfa3b9bc8542badf567aed Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Mon, 3 Jun 2024 10:56:01 +0200
Subject: [PATCH 23/30] ipv4transporthandle: use weakref

---
 src/seabreeze/pyseabreeze/transport.py | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index 7f0a52c5..9acc176b 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -13,6 +13,7 @@
 import socket
 import struct
 import warnings
+import weakref
 from functools import partialmethod
 from typing import TYPE_CHECKING
 from typing import Any
@@ -393,13 +394,15 @@ def __init__(self, sock: socket.socket) -> None:
         except OSError:
             address, port = None, None
         self.identity: tuple[str, int] = (address, port)
+        # register callback to close socket on garbage collection
+        self._finalizer = weakref.finalize(self, self.socket.close)
 
     def close(self) -> None:
-        # TODO check for exceptions that close() might throw
-        self.socket.close()
+        self._finalizer()
 
-    def __del__(self) -> None:
-        self.close()
+    @property
+    def closed(self) -> bool:
+        return not self._finalizer.alive
 
 
 class IPv4Transport(PySeaBreezeTransport[IPv4TransportHandle]):

From 4598793714768f350af371d5ae27b23006e7b9a8 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Mon, 3 Jun 2024 10:56:27 +0200
Subject: [PATCH 24/30] api: style improvement

---
 src/seabreeze/pyseabreeze/api.py | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/api.py b/src/seabreeze/pyseabreeze/api.py
index 51c7dcff..942853b9 100644
--- a/src/seabreeze/pyseabreeze/api.py
+++ b/src/seabreeze/pyseabreeze/api.py
@@ -51,9 +51,7 @@ def _seabreeze_device_factory(
     dev : SeaBreezeDevice
     """
     global _seabreeze_device_instance_registry
-    if not isinstance(device, USBTransportHandle) and not isinstance(
-        device, IPv4TransportHandle
-    ):
+    if not isinstance(device, (USBTransportHandle, IPv4TransportHandle)):
         raise TypeError(
             f"needs to be instance of USBTransportHandle or IPv4TransportHandle and not '{type(device)}'"
         )

From 6c362e1a79b2a3eb809114204d7880816b022bd9 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Mon, 3 Jun 2024 11:51:19 +0200
Subject: [PATCH 25/30] ipv4transport: reduce multicast timeout

---
 src/seabreeze/pyseabreeze/transport.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index 9acc176b..8c7a3692 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -523,7 +523,7 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
         sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
         # Set a timeout so the socket does not block
         # indefinitely when trying to receive data.
-        sock.settimeout(kwargs.get("multicast_timeout", 2))
+        sock.settimeout(kwargs.get("multicast_timeout", 1))
         sock.setsockopt(
             socket.IPPROTO_IP,
             socket.IP_MULTICAST_IF,

From 8b2f6173746651c08e1db9b3ae0b769f6133f287 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Mon, 3 Jun 2024 13:44:29 +0200
Subject: [PATCH 26/30] ipv4transporthandle: use DeviceIdentity type

+ fixes `mypy` errors
---
 src/seabreeze/pyseabreeze/transport.py | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index 8c7a3692..4ce7962a 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -393,7 +393,12 @@ def __init__(self, sock: socket.socket) -> None:
             address, port = sock.getpeername()
         except OSError:
             address, port = None, None
-        self.identity: tuple[str, int] = (address, port)
+        self.identity: DeviceIdentity = (
+            int(ipaddress.IPv4Address(address)),
+            port,
+            0,
+            0,
+        )
         # register callback to close socket on garbage collection
         self._finalizer = weakref.finalize(self, self.socket.close)
 
@@ -608,7 +613,12 @@ def supported_model(cls, device: IPv4TransportHandle) -> str | None:
         """
         if not isinstance(device, IPv4TransportHandle):
             return None
-        return cls.devices_ip_port[device.identity]
+        return cls.devices_ip_port[
+            # IP address
+            (str(ipaddress.IPv4Address(device.identity[0]))),
+            # port
+            device.identity[1],
+        ]
 
     @classmethod
     def specialize(cls, model_name: str, **kwargs: Any) -> type[IPv4Transport]:

From 001cea2e9c46b746d8296898803124a06a4a6e1f Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Mon, 3 Jun 2024 16:02:58 +0200
Subject: [PATCH 27/30] devices: fix mypy error

fixes `src/seabreeze/pyseabreeze/devices.py:317: error: "ABCMeta" has no attribute "supported_model"  [attr-defined]`
---
 src/seabreeze/pyseabreeze/devices.py | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/seabreeze/pyseabreeze/devices.py b/src/seabreeze/pyseabreeze/devices.py
index 04291ffa..e41deba5 100644
--- a/src/seabreeze/pyseabreeze/devices.py
+++ b/src/seabreeze/pyseabreeze/devices.py
@@ -313,7 +313,11 @@ def __new__(cls: type[DT], raw_device: Any = None) -> SeaBreezeDevice:
             raise SeaBreezeError(
                 "Don't instantiate SeaBreezeDevice directly. Use `SeabreezeAPI.list_devices()`."
             )
-        for transport in {USBTransport, IPv4Transport}:
+        transports: list[type[PySeaBreezeTransport[Any]]] = [
+            IPv4Transport,
+            USBTransport,
+        ]
+        for transport in transports:
             supported_model = transport.supported_model(raw_device)
             if supported_model is not None:
                 break

From 84405aacd3c63837198bf97be17b12815ac29f92 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Mon, 3 Jun 2024 16:07:13 +0200
Subject: [PATCH 28/30] ipv4transport: ignore known devices

protects against repeated runs of `list_devices` failing
---
 src/seabreeze/pyseabreeze/transport.py | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index 4ce7962a..22cb18d0 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -568,11 +568,15 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
                 # use known product ids of the USB transport to look up the model name
                 vid = 0x2457  # Ocean vendor ID
                 model = USBTransport.vendor_product_ids[(vid, pid)]
-                cls.register_model(
-                    model_name=model,
-                    ipv4_address=server[0],
-                    ipv4_port=server[1],
-                )
+                try:
+                    cls.register_model(
+                        model_name=model,
+                        ipv4_address=server[0],
+                        ipv4_port=server[1],
+                    )
+                except ValueError:
+                    # device already known
+                    pass
 
         # connect to discovered and registered devices
         dev_sockets = []

From 81e12426fd7506bfbe61423b51dc5b5bdec07b9c Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Tue, 4 Jun 2024 07:24:12 +0200
Subject: [PATCH 29/30] ipv4: handle allows reconnect

- change argument to handle from socket to ip+port
- manage opening socket in handle
- close socket in `list_devices`
---
 src/seabreeze/pyseabreeze/api.py       |  7 ++--
 src/seabreeze/pyseabreeze/transport.py | 46 ++++++++++++--------------
 2 files changed, 25 insertions(+), 28 deletions(-)

diff --git a/src/seabreeze/pyseabreeze/api.py b/src/seabreeze/pyseabreeze/api.py
index 942853b9..dc5937e2 100644
--- a/src/seabreeze/pyseabreeze/api.py
+++ b/src/seabreeze/pyseabreeze/api.py
@@ -141,11 +141,10 @@ def list_devices(self) -> list[_SeaBreezeDevice]:
                 # opening the device will populate its serial number
                 try:
                     dev.open()
-                except Exception:
-                    # TODO specify expected exception
+                except RuntimeError:
                     raise
-                # else:
-                #    dev.close()
+                else:
+                    dev.close()
             devices.append(dev)  # type: ignore
         return devices
 
diff --git a/src/seabreeze/pyseabreeze/transport.py b/src/seabreeze/pyseabreeze/transport.py
index 22cb18d0..43928e40 100644
--- a/src/seabreeze/pyseabreeze/transport.py
+++ b/src/seabreeze/pyseabreeze/transport.py
@@ -380,19 +380,14 @@ def get_name_from_pyusb_backend(backend: usb.backend.IBackend) -> str | None:
 
 # this can and should be opaque to pyseabreeze
 class IPv4TransportHandle:
-    def __init__(self, sock: socket.socket) -> None:
+    def __init__(self, address: str, port: int) -> None:
         """encapsulation for IPv4 socket classes
 
         Parameters
         ----------
 
         """
-        self.socket: socket.socket = sock
-        # TODO check if socket is connected and get address via socket (socket.getpeername())
-        try:
-            address, port = sock.getpeername()
-        except OSError:
-            address, port = None, None
+        self.socket: socket.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
         self.identity: DeviceIdentity = (
             int(ipaddress.IPv4Address(address)),
             port,
@@ -402,6 +397,14 @@ def __init__(self, sock: socket.socket) -> None:
         # register callback to close socket on garbage collection
         self._finalizer = weakref.finalize(self, self.socket.close)
 
+    def open(self) -> None:
+        # create a new socket; if we closed it, it will have lost its file descriptor
+        self.socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+        try:
+            self.socket.connect(self.get_address())
+        except OSError as e:
+            raise RuntimeError(f"Could not connect to {self.get_address()}: {e}")
+
     def close(self) -> None:
         self._finalizer()
 
@@ -409,6 +412,15 @@ def close(self) -> None:
     def closed(self) -> bool:
         return not self._finalizer.alive
 
+    def get_address(self) -> tuple[str, int]:
+        """Return a touple consisting of the ip address and the port."""
+        return (
+            # IP address
+            (str(ipaddress.IPv4Address(self.identity[0]))),
+            # port
+            self.identity[1],
+        )
+
 
 class IPv4Transport(PySeaBreezeTransport[IPv4TransportHandle]):
     """implementation of the IPv4 socket transport interface for spectrometers"""
@@ -434,8 +446,8 @@ def __init__(
     def open_device(self, device: IPv4TransportHandle) -> None:
         if not isinstance(device, IPv4TransportHandle):
             raise TypeError("device needs to be an IPv4TransportHandle")
-        # TODO handle possible exceptions
         self._device = device
+        self._device.open()
         self._opened = True
 
         # This will initialize the communication protocol
@@ -579,17 +591,8 @@ def list_devices(cls, **kwargs: Any) -> Iterable[IPv4TransportHandle]:
                     pass
 
         # connect to discovered and registered devices
-        dev_sockets = []
         for address in cls.devices_ip_port:
-            sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
-            try:
-                sock.connect(address)
-            except OSError as e:
-                raise RuntimeError(f"Could not connect to {address}: {e}")
-            else:
-                dev_sockets.append(sock)
-        for sock in dev_sockets:
-            yield IPv4TransportHandle(sock)
+            yield IPv4TransportHandle(*address)
 
     @classmethod
     def register_model(cls, model_name: str, **kwargs: Any) -> None:
@@ -617,12 +620,7 @@ def supported_model(cls, device: IPv4TransportHandle) -> str | None:
         """
         if not isinstance(device, IPv4TransportHandle):
             return None
-        return cls.devices_ip_port[
-            # IP address
-            (str(ipaddress.IPv4Address(device.identity[0]))),
-            # port
-            device.identity[1],
-        ]
+        return cls.devices_ip_port[device.get_address()]
 
     @classmethod
     def specialize(cls, model_name: str, **kwargs: Any) -> type[IPv4Transport]:

From 0e5a59ba0cbceabdb9074c7d279023eed515bce8 Mon Sep 17 00:00:00 2001
From: Hanno Perrey <hanno.perrey@dvel.se>
Date: Tue, 4 Jun 2024 12:37:08 +0200
Subject: [PATCH 30/30] pass network_adapter kwarg to backend

---
 src/seabreeze/backends.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/seabreeze/backends.py b/src/seabreeze/backends.py
index a0ca6a45..c0e3d49b 100644
--- a/src/seabreeze/backends.py
+++ b/src/seabreeze/backends.py
@@ -61,6 +61,9 @@ def use(
         if "pyusb_backend" in kwargs:
             pyusb_backend = kwargs.pop("pyusb_backend")
             BackendConfig.api_kwargs["pyusb_backend"] = pyusb_backend
+        if "network_adapter" in kwargs:
+            network_adapter = kwargs.pop("network_adapter")
+            BackendConfig.api_kwargs["network_adapter"] = network_adapter
     if kwargs:
         raise TypeError(
             f"unknown keyword arguments {set(kwargs)!r} for backend {backend!r}"