async def stop_notify(
self,
char_specifier: Union[BleakGATTCharacteristicBlueZDBus, int, str,
UUID],
) -> None:
"""Deactivate notification/indication on a specified characteristic.
Args:
char_specifier (BleakGATTCharacteristicBlueZDBus, int, str or UUID): The characteristic to deactivate
notification/indication on, specified by either integer handle, UUID or
directly by the BleakGATTCharacteristicBlueZDBus object representing it.
"""
if not self.is_connected:
raise BleakError("Not connected")
if not isinstance(char_specifier, BleakGATTCharacteristicBlueZDBus):
characteristic = self.services.get_characteristic(char_specifier)
else:
characteristic = char_specifier
if not characteristic:
raise BleakError(
"Characteristic {} not found!".format(char_specifier))
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=characteristic.path,
interface=defs.GATT_CHARACTERISTIC_INTERFACE,
member="StopNotify",
))
assert_reply(reply)
self._notification_callbacks.pop(characteristic.path, None)
async def _acquire_mtu(self) -> None:
"""Acquires the MTU for this device by calling the "AcquireWrite" or
"AcquireNotify" method of the first characteristic that has such a method.
This method only needs to be called once, after connecting to the device
but before accessing the ``mtu_size`` property.
If a device uses encryption on characteristics, it will need to be bonded
first before calling this method.
"""
# This will try to get the "best" characteristic for getting the MTU.
# We would rather not start notifications if we don't have to.
try:
method = "AcquireWrite"
char = next(c for c in self.services.characteristics.values()
if "write-without-response" in c.properties)
except StopIteration:
method = "AcquireNotify"
char = next(c for c in self.services.characteristics.values()
if "notify" in c.properties)
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=char.path,
interface=defs.GATT_CHARACTERISTIC_INTERFACE,
member=method,
signature="a{sv}",
body=[{}],
))
assert_reply(reply)
# we aren't actually using the write or notify, we just want the MTU
os.close(reply.unix_fds[0])
self._mtu_size = reply.body[1]
async def write_gatt_descriptor(
self, handle: int, data: Union[bytes, bytearray,
memoryview]) -> None:
"""Perform a write operation on the specified GATT descriptor.
Args:
handle (int): The handle of the descriptor to read from.
data (bytes or bytearray): The data to send.
"""
if not self.is_connected:
raise BleakError("Not connected")
descriptor = self.services.get_descriptor(handle)
if not descriptor:
raise BleakError(
"Descriptor with handle {0} was not found!".format(handle))
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=descriptor.path,
interface=defs.GATT_DESCRIPTOR_INTERFACE,
member="WriteValue",
signature="aya{sv}",
body=[bytes(data), {
"type": Variant("s", "command")
}],
))
assert_reply(reply)
logger.debug("Write Descriptor {0} | {1}: {2}".format(
handle, descriptor.path, data))
async def read_gatt_descriptor(self, handle: int, **kwargs) -> bytearray:
"""Perform read operation on the specified GATT descriptor.
Args:
handle (int): The handle of the descriptor to read from.
Returns:
(bytearray) The read data.
"""
if not self.is_connected:
raise BleakError("Not connected")
descriptor = self.services.get_descriptor(handle)
if not descriptor:
raise BleakError(
"Descriptor with handle {0} was not found!".format(handle))
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=descriptor.path,
interface=defs.GATT_DESCRIPTOR_INTERFACE,
member="ReadValue",
signature="a{sv}",
body=[{}],
))
assert_reply(reply)
value = bytearray(reply.body[0])
logger.debug("Read Descriptor {0} | {1}: {2}".format(
handle, descriptor.path, value))
return value
async def disconnect(self) -> bool:
"""Disconnect from the specified GATT server.
Returns:
Boolean representing if device is disconnected.
Raises:
BleakDBusError: If there was a D-Bus error
asyncio.TimeoutError if the device was not disconnected within 10 seconds
"""
logger.debug(f"Disconnecting ({self._device_path})")
if self._bus is None:
# No connection exists. Either one hasn't been created or
# we have already called disconnect and closed the D-Bus
# connection.
logger.debug(f"already disconnected ({self._device_path})")
return True
if self._disconnecting_event:
# another call to disconnect() is already in progress
logger.debug(f"already in progress ({self._device_path})")
await asyncio.wait_for(self._disconnecting_event.wait(),
timeout=10)
elif self.is_connected:
self._disconnecting_event = asyncio.Event()
try:
# Try to disconnect the actual device/peripheral
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=self._device_path,
interface=defs.DEVICE_INTERFACE,
member="Disconnect",
))
assert_reply(reply)
await asyncio.wait_for(self._disconnecting_event.wait(),
timeout=10)
finally:
self._disconnecting_event = None
# sanity check to make sure _cleanup_all() was triggered by the
# "PropertiesChanged" signal handler and that it completed successfully
assert self._bus is None
# Reset all stored services.
self.services = BleakGATTServiceCollection()
self._services_resolved = False
return True
async def stop(self):
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=self._adapter_path,
interface=defs.ADAPTER_INTERFACE,
member="StopDiscovery",
)
)
assert_reply(reply)
for rule in self._rules:
await remove_match(self._bus, rule)
self._rules.clear()
self._bus.remove_message_handler(self._parse_msg)
# Try to disconnect the System Bus.
try:
self._bus.disconnect()
except Exception as e:
logger.error("Attempt to disconnect system bus failed: {0}".format(e))
self._bus = None
async def connect(self, **kwargs) -> bool:
"""Connect to the specified GATT server.
Keyword Args:
timeout (float): Timeout for required ``BleakScanner.find_device_by_address`` call. Defaults to 10.0.
Returns:
Boolean representing connection status.
Raises:
BleakError: If the device is already connected or if the device could not be found.
BleakDBusError: If there was a D-Bus error
asyncio.TimeoutError: If the connection timed out
"""
logger.debug(
f"Connecting to device @ {self.address} with {self._adapter}")
if self.is_connected:
raise BleakError("Client is already connected")
# A Discover must have been run before connecting to any devices.
# Find the desired device before trying to connect.
timeout = kwargs.get("timeout", self._timeout)
if self._device_path is None:
device = await BleakScannerBlueZDBus.find_device_by_address(
self.address, timeout=timeout, adapter=self._adapter)
if device:
self._device_info = device.details.get("props")
self._device_path = device.details["path"]
else:
raise BleakError(
"Device with address {0} was not found.".format(
self.address))
# Create system bus
self._bus = await MessageBus(bus_type=BusType.SYSTEM,
negotiate_unix_fd=True).connect()
try:
# Add signal handlers. These monitor the device D-Bus object and
# all of its descendats (services, characteristics, descriptors).
# This we always have an up-to-date state for all of these that is
# maintained automatically in the background.
self._bus.add_message_handler(self._parse_msg)
rules = MatchRules(
interface=defs.OBJECT_MANAGER_INTERFACE,
member="InterfacesAdded",
arg0path=f"{self._device_path}/",
)
reply = await add_match(self._bus, rules)
assert_reply(reply)
rules = MatchRules(
interface=defs.OBJECT_MANAGER_INTERFACE,
member="InterfacesRemoved",
arg0path=f"{self._device_path}/",
)
reply = await add_match(self._bus, rules)
assert_reply(reply)
rules = MatchRules(
interface=defs.PROPERTIES_INTERFACE,
member="PropertiesChanged",
path_namespace=self._device_path,
)
reply = await add_match(self._bus, rules)
assert_reply(reply)
# Find the HCI device to use for scanning and get cached device properties
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path="/",
member="GetManagedObjects",
interface=defs.OBJECT_MANAGER_INTERFACE,
))
assert_reply(reply)
interfaces_and_props: Dict[str, Dict[str, Variant]] = reply.body[0]
# The device may have been removed from BlueZ since the time we stopped scanning
if self._device_path not in interfaces_and_props:
# Sometimes devices can be removed from the BlueZ object manager
# before we connect to them. In this case we try using the
# org.bluez.Adapter1.ConnectDevice method instead. This method
# requires that bluetoothd is run with the --experimental flag
# and is available since BlueZ 5.49.
logger.debug(
f"org.bluez.Device1 object not found, trying org.bluez.Adapter1.ConnectDevice ({self._device_path})"
)
reply = await asyncio.wait_for(
self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
interface=defs.ADAPTER_INTERFACE,
path=f"/org/bluez/{self._adapter}",
member="ConnectDevice",
signature="a{sv}",
body=[{
"Address":
Variant("s", self._device_info["Address"]),
"AddressType":
Variant("s", self._device_info["AddressType"]),
}],
)),
timeout,
)
# FIXME: how to cancel connection if timeout?
if (reply.message_type == MessageType.ERROR and
reply.error_name == ErrorType.UNKNOWN_METHOD.value):
logger.debug(
f"org.bluez.Adapter1.ConnectDevice not found ({self._device_path}), try enabling bluetoothd --experimental"
)
raise BleakError(
"Device with address {0} could not be found. "
"Try increasing `timeout` value or moving the device closer."
.format(self.address))
assert_reply(reply)
else:
# required interface
self._properties = unpack_variants(interfaces_and_props[
self._device_path][defs.DEVICE_INTERFACE])
# optional interfaces - services and characteristics may not
# be populated yet
for path, interfaces in interfaces_and_props.items():
if not path.startswith(self._device_path):
continue
if defs.GATT_SERVICE_INTERFACE in interfaces:
obj = unpack_variants(
interfaces[defs.GATT_SERVICE_INTERFACE])
self.services.add_service(
BleakGATTServiceBlueZDBus(obj, path))
if defs.GATT_CHARACTERISTIC_INTERFACE in interfaces:
obj = unpack_variants(
interfaces[defs.GATT_CHARACTERISTIC_INTERFACE])
service = interfaces_and_props[obj["Service"]][
defs.GATT_SERVICE_INTERFACE]
uuid = service["UUID"].value
handle = extract_service_handle_from_path(
obj["Service"])
self.services.add_characteristic(
BleakGATTCharacteristicBlueZDBus(
obj, path, uuid, handle))
if defs.GATT_DESCRIPTOR_INTERFACE in interfaces:
obj = unpack_variants(
interfaces[defs.GATT_DESCRIPTOR_INTERFACE])
characteristic = interfaces_and_props[
obj["Characteristic"]][
defs.GATT_CHARACTERISTIC_INTERFACE]
uuid = characteristic["UUID"].value
handle = extract_service_handle_from_path(
obj["Characteristic"])
self.services.add_descriptor(
BleakGATTDescriptorBlueZDBus(
obj, path, uuid, handle))
try:
reply = await asyncio.wait_for(
self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
interface=defs.DEVICE_INTERFACE,
path=self._device_path,
member="Connect",
)),
timeout,
)
assert_reply(reply)
except BaseException:
# calling Disconnect cancels any pending connect request
try:
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
interface=defs.DEVICE_INTERFACE,
path=self._device_path,
member="Disconnect",
))
try:
assert_reply(reply)
except BleakDBusError as e:
# if the object no longer exists, then we know we
# are disconnected for sure, so don't need to log a
# warning about it
if e.dbus_error != ErrorType.UNKNOWN_OBJECT.value:
raise
except Exception as e:
logger.warning(
f"Failed to cancel connection ({self._device_path}): {e}"
)
raise
if self.is_connected:
logger.debug(f"Connection successful ({self._device_path})")
else:
raise BleakError(
f"Connection was not successful! ({self._device_path})")
# Create a task that runs until the device is disconnected.
self._disconnect_monitor_event = asyncio.Event()
asyncio.ensure_future(self._disconnect_monitor())
# Get all services. This means making the actual connection.
await self.get_services()
return True
except BaseException:
self._cleanup_all()
raise
async def start_notify(
self,
char_specifier: Union[BleakGATTCharacteristicBlueZDBus, int, str,
UUID],
callback: Callable[[int, bytearray], None],
**kwargs,
) -> None:
"""Activate notifications/indications on a characteristic.
Callbacks must accept two inputs. The first will be a integer handle of the characteristic generating the
data and the second will be a ``bytearray`` containing the data sent from the connected server.
.. code-block:: python
def callback(sender: int, data: bytearray):
print(f"{sender}: {data}")
client.start_notify(char_uuid, callback)
Args:
char_specifier (BleakGATTCharacteristicBlueZDBus, int, str or UUID): The characteristic to activate
notifications/indications on a characteristic, specified by either integer handle,
UUID or directly by the BleakGATTCharacteristicBlueZDBus object representing it.
callback (function): The function to be called on notification.
"""
if not self.is_connected:
raise BleakError("Not connected")
if inspect.iscoroutinefunction(callback):
def bleak_callback(s, d):
asyncio.ensure_future(callback(s, d))
else:
bleak_callback = callback
if not isinstance(char_specifier, BleakGATTCharacteristicBlueZDBus):
characteristic = self.services.get_characteristic(char_specifier)
else:
characteristic = char_specifier
if not characteristic:
# Special handling for BlueZ >= 5.48, where Battery Service (0000180f-0000-1000-8000-00805f9b34fb:)
# has been moved to interface org.bluez.Battery1 instead of as a regular service.
# The org.bluez.Battery1 on the other hand does not provide a notification method, so here we cannot
# provide this functionality...
# See https://kernel.googlesource.com/pub/scm/bluetooth/bluez/+/refs/tags/5.48/doc/battery-api.txt
if str(char_specifier
) == "00002a19-0000-1000-8000-00805f9b34fb" and (
self._hides_battery_characteristic):
raise BleakError(
"Notifications on Battery Level Char ({0}) is not "
"possible in BlueZ >= 5.48. Use regular read instead.".
format(char_specifier))
raise BleakError(
"Characteristic with UUID {0} could not be found!".format(
char_specifier))
self._notification_callbacks[characteristic.path] = bleak_callback
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=characteristic.path,
interface=defs.GATT_CHARACTERISTIC_INTERFACE,
member="StartNotify",
))
assert_reply(reply)
async def write_gatt_char(
self,
char_specifier: Union[BleakGATTCharacteristicBlueZDBus, int, str,
UUID],
data: Union[bytes, bytearray, memoryview],
response: bool = False,
) -> None:
"""Perform a write operation on the specified GATT characteristic.
.. note::
The version check below is for the "type" option to the
"Characteristic.WriteValue" method that was added to `Bluez in 5.51
<https://git.kernel.org/pub/scm/bluetooth/bluez.git/commit?id=fa9473bcc48417d69cc9ef81d41a72b18e34a55a>`_
Before that commit, ``Characteristic.WriteValue`` was only "Write with
response". ``Characteristic.AcquireWrite`` was `added in Bluez 5.46
<https://git.kernel.org/pub/scm/bluetooth/bluez.git/commit/doc/gatt-api.txt?id=f59f3dedb2c79a75e51a3a0d27e2ae06fefc603e>`_
which can be used to "Write without response", but for older versions
of Bluez, it is not possible to "Write without response".
Args:
char_specifier (BleakGATTCharacteristicBlueZDBus, int, str or UUID): The characteristic to write
to, specified by either integer handle, UUID or directly by the
BleakGATTCharacteristicBlueZDBus object representing it.
data (bytes or bytearray): The data to send.
response (bool): If write-with-response operation should be done. Defaults to `False`.
"""
if not self.is_connected:
raise BleakError("Not connected")
if not isinstance(char_specifier, BleakGATTCharacteristicBlueZDBus):
characteristic = self.services.get_characteristic(char_specifier)
else:
characteristic = char_specifier
if not characteristic:
raise BleakError(
"Characteristic {0} was not found!".format(char_specifier))
if ("write" not in characteristic.properties
and "write-without-response" not in characteristic.properties):
raise BleakError(
"Characteristic %s does not support write operations!" %
str(characteristic.uuid))
if not response and "write-without-response" not in characteristic.properties:
response = True
# Force response here, since the device only supports that.
if (response and "write" not in characteristic.properties
and "write-without-response" in characteristic.properties):
response = False
logger.warning(
"Characteristic %s does not support Write with response. Trying without..."
% str(characteristic.uuid))
# See docstring for details about this handling.
if not response and not self._can_write_without_response:
raise BleakError(
"Write without response requires at least BlueZ 5.46")
if response or not self._write_without_response_workaround_needed:
# TODO: Add OnValueUpdated handler for response=True?
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=characteristic.path,
interface=defs.GATT_CHARACTERISTIC_INTERFACE,
member="WriteValue",
signature="aya{sv}",
body=[
bytes(data),
{
"type":
Variant("s", "request" if response else "command")
},
],
))
assert_reply(reply)
else:
# Older versions of BlueZ don't have the "type" option, so we have
# to write the hard way. This isn't the most efficient way of doing
# things, but it works.
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=characteristic.path,
interface=defs.GATT_CHARACTERISTIC_INTERFACE,
member="AcquireWrite",
signature="a{sv}",
body=[{}],
))
assert_reply(reply)
fd = reply.unix_fds[0]
try:
os.write(fd, data)
finally:
os.close(fd)
logger.debug("Write Characteristic {0} | {1}: {2}".format(
characteristic.uuid, characteristic.path, data))
async def read_gatt_char(
self,
char_specifier: Union[BleakGATTCharacteristicBlueZDBus, int, str,
UUID],
**kwargs,
) -> bytearray:
"""Perform read operation on the specified GATT characteristic.
Args:
char_specifier (BleakGATTCharacteristicBlueZDBus, int, str or UUID): The characteristic to read from,
specified by either integer handle, UUID or directly by the
BleakGATTCharacteristicBlueZDBus object representing it.
Returns:
(bytearray) The read data.
"""
if not self.is_connected:
raise BleakError("Not connected")
if not isinstance(char_specifier, BleakGATTCharacteristicBlueZDBus):
characteristic = self.services.get_characteristic(char_specifier)
else:
characteristic = char_specifier
if not characteristic:
# Special handling for BlueZ >= 5.48, where Battery Service (0000180f-0000-1000-8000-00805f9b34fb:)
# has been moved to interface org.bluez.Battery1 instead of as a regular service.
if str(char_specifier
) == "00002a19-0000-1000-8000-00805f9b34fb" and (
self._hides_battery_characteristic):
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=self._device_path,
interface=defs.PROPERTIES_INTERFACE,
member="GetAll",
signature="s",
body=[defs.BATTERY_INTERFACE],
))
assert_reply(reply)
# Simulate regular characteristics read to be consistent over all platforms.
value = bytearray(reply.body[0]["Percentage"].value)
logger.debug("Read Battery Level {0} | {1}: {2}".format(
char_specifier, self._device_path, value))
return value
if str(char_specifier
) == "00002a00-0000-1000-8000-00805f9b34fb" and (
self._hides_device_name_characteristic):
# Simulate regular characteristics read to be consistent over all platforms.
value = bytearray(self._properties["Name"].encode("ascii"))
logger.debug("Read Device Name {0} | {1}: {2}".format(
char_specifier, self._device_path, value))
return value
raise BleakError(
"Characteristic with UUID {0} could not be found!".format(
char_specifier))
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=characteristic.path,
interface=defs.GATT_CHARACTERISTIC_INTERFACE,
member="ReadValue",
signature="a{sv}",
body=[{}],
))
assert_reply(reply)
value = bytearray(reply.body[0])
logger.debug("Read Characteristic {0} | {1}: {2}".format(
characteristic.uuid, characteristic.path, value))
return value
async def pair(self, *args, **kwargs) -> bool:
"""Pair with the peripheral.
You can use ConnectDevice method if you already know the MAC address of the device.
Else you need to StartDiscovery, Trust, Pair and Connect in sequence.
Returns:
Boolean regarding success of pairing.
"""
# See if it is already paired.
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=self._device_path,
interface=defs.PROPERTIES_INTERFACE,
member="Get",
signature="ss",
body=[defs.DEVICE_INTERFACE, "Paired"],
))
assert_reply(reply)
if reply.body[0].value:
logger.debug(
f"BLE device @ {self.address} already paired with {self._adapter}"
)
return True
# Set device as trusted.
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=self._device_path,
interface=defs.PROPERTIES_INTERFACE,
member="Set",
signature="ssv",
body=[defs.DEVICE_INTERFACE, "Trusted",
Variant("b", True)],
))
assert_reply(reply)
logger.debug("Pairing to BLE device @ {0} with {1}".format(
self.address, self._adapter))
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=self._device_path,
interface=defs.DEVICE_INTERFACE,
member="Pair",
))
assert_reply(reply)
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=self._device_path,
interface=defs.PROPERTIES_INTERFACE,
member="Get",
signature="ss",
body=[defs.DEVICE_INTERFACE, "Paired"],
))
assert_reply(reply)
return reply.body[0].value
async def start(self):
self._bus = await MessageBus(bus_type=BusType.SYSTEM).connect()
self._devices.clear()
self._cached_devices.clear()
# Add signal listeners
self._bus.add_message_handler(self._parse_msg)
rules = MatchRules(
interface=defs.OBJECT_MANAGER_INTERFACE,
member="InterfacesAdded",
arg0path=f"{self._adapter_path}/",
)
reply = await add_match(self._bus, rules)
assert_reply(reply)
self._rules.append(rules)
rules = MatchRules(
interface=defs.OBJECT_MANAGER_INTERFACE,
member="InterfacesRemoved",
arg0path=f"{self._adapter_path}/",
)
reply = await add_match(self._bus, rules)
assert_reply(reply)
self._rules.append(rules)
rules = MatchRules(
interface=defs.PROPERTIES_INTERFACE,
member="PropertiesChanged",
path_namespace=self._adapter_path,
)
reply = await add_match(self._bus, rules)
assert_reply(reply)
self._rules.append(rules)
# Find the HCI device to use for scanning and get cached device properties
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path="/",
member="GetManagedObjects",
interface=defs.OBJECT_MANAGER_INTERFACE,
)
)
assert_reply(reply)
# get only the device interface
self._cached_devices = {
path: unpack_variants(interfaces[defs.DEVICE_INTERFACE])
for path, interfaces in reply.body[0].items()
if defs.DEVICE_INTERFACE in interfaces
}
logger.debug(f"cached devices: {self._cached_devices}")
# Apply the filters
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=self._adapter_path,
interface=defs.ADAPTER_INTERFACE,
member="SetDiscoveryFilter",
signature="a{sv}",
body=[self._filters],
)
)
assert_reply(reply)
# Start scanning
reply = await self._bus.call(
Message(
destination=defs.BLUEZ_SERVICE,
path=self._adapter_path,
interface=defs.ADAPTER_INTERFACE,
member="StartDiscovery",
)
)
assert_reply(reply)
