bleak 0.12.1

Bluetooth Low Energy platform Agnostic Klient

bleak

Bleak is an acronym for Bluetooth Low Energy platform Agnostic Klient.

• Free software: MIT license

• Documentation: https://bleak.readthedocs.io.

Bleak is a GATT client software, capable of connecting to BLE devices acting as GATT servers. It is designed to provide a asynchronous, cross-platform Python API to connect and communicate with e.g. sensors.

Installation

$ pip install bleak

Features

• Supports Windows 10, version 16299 (Fall Creators Update) or greater

• Supports Linux distributions with BlueZ >= 5.43

• OS X/macOS support via Core Bluetooth API, from at least OS X version 10.11

Bleak supports reading, writing and getting notifications from GATT servers, as well as a function for discovering BLE devices.

Usage

To discover Bluetooth devices that can be connected to:

import asyncio
from bleak import BleakScanner

async def run():
    devices = await BleakScanner.discover()
    for d in devices:
        print(d)

loop = asyncio.get_event_loop()
loop.run_until_complete(run())

Connect to a Bluetooth device and read its model number:

import asyncio
from bleak import BleakClient

address = "24:71:89:cc:09:05"
MODEL_NBR_UUID = "00002a24-0000-1000-8000-00805f9b34fb"

async def run(address):
    async with BleakClient(address) as client:
        model_number = await client.read_gatt_char(MODEL_NBR_UUID)
        print("Model Number: {0}".format("".join(map(chr, model_number))))

loop = asyncio.get_event_loop()
loop.run_until_complete(run(address))

See examples folder for more code, for instance example code for connecting to a TI SensorTag CC2650

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

0.12.1 (2021-07-07)

Changed

• Changed minimum winrt package version to 1.0.21033.1. Fixes #589.

Fixed

• Fixed unawaited future when writing without response on CoreBluetooth backend. Fixes #586.

0.12.0 (2021-06-19)

Added

• Added mtu_size property for clients.

• Added WinRT backend.

• Added BleakScanner.discovered_devices property.

• Added an event to await when stopping scanners in WinRT and pythonnet backends. Fixes #556.

• Added BleakScanner.find_device_by_filter static method.

• Added scanner_byname.py example.

• Added optional command line argument to specify device to all applicable examples.

Changed

• Added Programming Language :: Python :: 3.9 classifier in setup.py.

• Deprecated BleakScanner.get_discovered_devices() async method.

• Added capability to handle async functions as detection callbacks in BleakScanner.

• Added error description in addition to error name when BleakDBusError is converted to string.

• Change typing of data parameter in write methods to Union[bytes, bytearray, memoryview].

• Improved type hints in CoreBluetooth backend.

• Use delegate callbacks for get_rssi() on CoreBluetooth backend.

• Use @objc.python_method where possible in PeripheralDelegate class.

• Using ObjC key-value observer to wait for BleakScanner.start() and stop() in CoreBluetooth backend.

Fixed

• Fixed KeyError when trying to connect to BLEDevice from advertising data callback on macOS. Fixes #448.

• Handling of undetected devices in connect_by_bledevice.py example. Fixes #487.

• Added Optional typehint for BleakScanner.find_device_by_address.

• Fixed linux_autodoc_mock_import in docs/conf.py.

• Minor fix for disconnection event handling in BlueZ backend. Fixes #491.

• Corrections for the Philips Hue lamp example. Merged #505.

• Fixed BleakClientBlueZDBus.pair() method always returning True. Fixes #503.

• Fixed waiting for notification start/stop to complete in CoreBluetooth backend.

• Fixed write without response on BlueZ < 5.51.

• Fixed error propagation for CoreBluetooth events.

• Fixed failed import on CI server when BlueZ is not installed.

• Fixed notification value should be bytearray on CoreBluetooth. Fixes #560.

• Fixed crash when cancelling connection when Python runtime shuts down on CoreBluetooth backend. Fixes #538.

• Fixed connecting to multiple devices using a single BleakScanner on CoreBluetooth backend.

• Fixed deadlock in CoreBluetooth backend when device disconnects while callbacks are pending. Fixes #535.

• Fixed deadlock when using more than one service, characteristic or descriptor with the same UUID on CoreBluetooth backend.

• Fixed exception raised when calling BleakScanner.stop() when already stopped in CoreBluetooth backend.

0.11.0 (2021-03-17)

Added

• Updated dotnet.client.BleakClientDotNet connect method docstring.

• Added AdvertisementServiceData in BLEDevice in macOS devices

• Protection levels (encryption) in Windows backend pairing. Solves #405.

• Philips Hue lamp example script. Relates to #405.

• Keyword arguments to get_services method on BleakClient.

• Keyword argument use_cached on .NET backend, to enable uncached reading of services, characteristics and descriptors in Windows.

• Documentation on troubleshooting OS level caches for services.

• New example added: Async callbacks with a queue and external consumer

• handle property on BleakGATTService objects

• service_handle property on BleakGATTCharacteristic objects

• Added more specific type hints for BleakGATTServiceCollection properties.

• Added asyncio task to disconnect devices on event loop crash in BlueZ backend.

• Added filtering on advertisement data callbacks on BlueZ backend so that callbacks only occur when advertising data changes like on macOS backend.

• Added fallback to try org.bluez.Adapter1.ConnectDevice when trying to connect a device in BlueZ backend.

• Added UART service example.

Fixed

• Fixed wrong OS write method called in write_gatt_descriptor() in Windows backend. Merged #403.

• Fixed BaseBleakClient.services_resolved not reset on disconnect on BlueZ backend. Merged #401.

• Fixed RSSI missing in discovered devices on macOS backend. Merged #400.

• Fixed scan result shows ‘Unknown’ name of the BLEDevice. Fixes #371.

• Fixed a broken check for the correct adapter in BleakClientBlueZDBus.

• Fixed #445 and #362 for Windows.

Changed

• Using handles to identify the services. Added handle abstract property to BleakGATTService and storing the services by handle instead of UUID.

• Changed BleakScanner.set_scanning_filter() from async method to normal method.

• Changed BlueZ backend to use dbus-next instead of txdbus.

• Changed BleakClient.is_connected from async method to property.

• Consolidated D-Bus signal debug messages in BlueZ backend.

Removed

• Removed all __str__ methods from backend service, characteristic and descriptor implementations in favour of those in the abstract base classes.

0.10.0 (2020-12-11)

Added

• Added AdvertisementData class used with detection callbacks across all supported platforms. Merged #334.

• Added BleakError raised during import on unsupported platforms.

• Added rssi parameter to BLEDevice constructor.

• Added detection_callback kwarg to BleakScanner constructor.

Changed

• Updated minimum PyObjC version to 7.0.1.

• Consolidated implementation of BleakScanner.register_detection_callback(). All platforms now take callback with BLEDevice and AdvertisementData arguments.

• Consolidated BleakScanner.find_device_by_address() implementations.

• Renamed “device” kwarg to “adapter” in BleakClient and BleakScanner. Fixes #381.

Fixed

• Fixed use of bare exceptions.

• Fixed BleakClientBlueZDBus.start_notify() misses initial notifications with fast Bluetooth devices. Fixed #374.

• Fix event callbacks on Windows not running in asyncio event loop thread.

• Fixed BleakScanner.discover() on older versions of macOS. Fixes #331.

• Fixed disconnect callback on BlueZ backend.

• Fixed calling BleakClient.is_connected() on Mac before connection.

• Fixed kwargs ignored in BleakScanner.find_device_by_address() in BlueZ backend. Fixes #360.

Removed

• Removed duplicate definition of BLEDevice in BlueZ backend.

• Removed unused imports.

• Removed separate implementation of global discover method.

0.9.1 (2020-10-22)

Added

• Added new attribute _device_info on BleakClientBlueZDBus. Merges #347.

• Added Pull Request Template.

Changed

• Updated instructions on how to contribute, file issues and make PRs.

• Updated AUTHORS.rst file with development team.

Fixed

• Fix well-known services not converted to UUIDs in BLEDevice.metadata in CoreBluetooth backend. Fixes #342.

• Fix advertising data replaced instead of merged in scanner in CoreBluetooth backend. Merged #343.

• Fix CBCentralManager not properly waited for during initialization in some cases.

• Fix AttributeError in CoreBluetooth when using BLEDeviceCoreBluetooth object.

0.9.0 (2020-10-20)

Added

• Timeout for BlueZ backend connect call to avoid potential infinite hanging. Merged #306.

• Added Interfaces API docs again.

• Troubleshooting documentation.

• noqa flags added to BleakBridge imports.

• Adding a timeout on OSX so that the connect cannot hang forever. Merge #336.

Changed

• BleakCharacteristic.description() on .NET now returns the same value as other platforms.

• Changed all adding and removal of .NET event handler from +=/-= syntax to calling add_ and remove_ methods instead. This allows for proper removal of event handlers in .NET backend.

• All code dependence on the BleakBridge is now removed. It is only imported to allow for access to UWP namespaces.

• Removing internal method _start_notify in the .NET backend.

• GattSession object now manages lifetime of .NET BleakClient connection.

• BleakClient in .NET backend will reuse previous device information when reconnecting so that it doesn’t have to scan/discover again.

Fixed

• UUID property bug fixed in BlueZ backend. Merged #307.

• Fix for broken RTD documentation.

• Fix UUID string arguments should not be case sensitive.

• Fix BleakGATTService.get_characteristic() method overridden with NotImplementedError in BlueZ backend.

• Fix AttributeError when trying to connect using CoreBluetooth backend. Merged #323.

• Fix disconnect callback called multiple times in .NET backend. Fixes #312.

• Fix BleakClient.disconnect() method failing when called multiple times in .NET backend. Fixes #313.

• Fix BleakClient.disconnect() method failing when called multiple times in Core Bluetooth backend. Merge #333.

• Catch RemoteError in is_connected in BlueZ backend. Fixes #310,

• Prevent overwriting address in constructor of BleakClient in BlueZ backend. Merge #311.

• Fix nordic uart UUID. Merge #339.

0.8.0 (2020-09-22)

Added

• Implemented set_disconnected_callback in the .NET backend BleakClient implementation.

• Added find_device_by_address method to the BleakScanner interface, for stopping scanning when a desired address is found.

• Implemented find_device_by_address in the .NET backend BleakScanner implementation and switched its BleakClient implementation to use that method in connect.

• Implemented find_device_by_address in the BlueZ backend BleakScanner implementation and switched its BleakClient implementation to use that method in connect.

• Implemented find_device_by_address in the Core Bluetooth backend BleakScanner implementation and switched its BleakClient implementation to use that method in connect.

• Added text representations of Protocol Errors that are visible in the .NET backend. Added these texts to errors raised.

• Added pairing method in BleakClient interface.

• Implemented pairing method in .NET backend.

• Implemented pairing method in the BlueZ backend.

• Added stumps and NotImplementedError on pairing in macOS backend.

• Added the possibility to connect using BLEDevice instead of a string address. This allows for skipping the discovery call when connecting.

Removed

• Support for Python 3.5.

Changed

• BREAKING CHANGE All notifications now have the characteristic’s integer handle instead of its UUID as a string as the first argument sender sent to notification callbacks. This provides the uniqueness of sender in notifications as well.

• Renamed BleakClient argument address to address_or_ble_device.

• Version 0.5.0 of BleakUWPBridge, with some modified methods and implementing IDisposable.

• Merged #224. All storing and passing of event loops in bleak is removed.

• Removed Objective C delegate compliance checks. Merged #253.

• Made context managers for .NET DataReader and DataWriter.

Fixed

• .NET backend loop handling bug entered by #224 fixed.

• Removed default DEBUG level set to bleak logger. Fixes #251.

• More coherency in logger uses over all backends. Fixes #258

• Attempted fix of #255 and #133: cleanups, disposing of objects and creating new BleakBridge instances each disconnect.

• Fixed some type hints and docstrings.

• Modified the connected_peripheral_delegate handling in macOS backend to fix #213 and #116.

• Merged #270, fixing a critical bug in get_services method in Core Bluetooth backend.

• Improved handling of disconnections and is_connected in BlueZ backend to fix #259.

• Fix for set_disconnected_callback on Core Bluetooth. Fixes #276.

• Safer Core Bluetooth presence check. Merged #280.

0.7.1 (2020-07-02)

Changed

• Improved, more explanatory error on BlueZ backend when BleakClient cannot find the desired device when trying to connect. (#238)

• Better-than-nothing documentation about scanning filters added (#230).

• Ran black on code which was forgotten in 0.7.0. Large diffs due to that.

• Re-adding Python 3.8 CI “tests” on Windows again.

Fixed

• Fix when characteristic updates value faster than asyncio schedule (#240 & #241)

• Incorrect MANIFEST.in corrected. (#244)

0.7.0 (2020-06-30)

Added

• Better feedback of communication errors to user in .NET backend and implementing error details proposed in #174.

• Two devices example file to use for e.g. debugging.

• Detection/discovery callbacks in Core Bluetooth backend Scanner implemented.

• Characteristic handle printout in service_explorer.py.

• Added scanning filters to .NET backend’s discover method.

Changed

• Replace NSRunLoop with dispatch queue in Core Bluetooth backend. This causes callbacks to be dispatched on a background thread instead of on the main dispatch queue on the main thread. call_soon_threadsafe() is used to synchronize the events with the event loop where the central manager was created. Fixes #111.

• The Central Manager is no longer global in the Core Bluetooth backend. A new one is created for each BleakClient and BleakScanner. Fixes #206 and #105.

• Merged #167 and reworked characteristics handling in Bleak. Implemented in all backends; bleak now uses the characteristics’ handle to identify and keep track of them. Fixes #139 and #159 and allows connection for devices with multiple instances of the same characteristic UUIDs.

• In requirements.txt and Pipfile, the requirement on pythonnet was bumped to version 2.5.1, which seems to solve issues described in #217 and #225.

• Renamed HISTORY.rst to CHANGELOG.rst and adopted the Keep a Changelog format.

• Python 3.5 support from macOS is officially removed since pyobjc>6 requires 3.6+

• Pin pyobjc dependencies to use at least version 6.2. (PR #194)

• Pin development requirement on bump2version to version 1.0.0

• Added .pyup.yml for Pyup

• Using CBManagerState constants from pyobj instead of integers.

Removed

• Removed documentation note about not using new event loops in Linux. This was fixed by #143.

• _central_manager_delegate_ready was removed in macOS backend.

• Removed the bleak.backends.bluez.utils.get_gatt_service_path method. It is not used by bleak and possibly generates errors.

Fixed

• Improved handling of the txdbus connection to avoid hanging of disconnection clients in BlueZ backend. Fixes #216, #219 & #221.

• #150 hints at the device path not being possible to create as is done in the get_device_object_path method. Now, we try to get it from BlueZ first. Otherwise, use the old fallback.

• Minor documentation errors corrected.

• CBManagerStatePoweredOn is now properly handled in Core Bluetooth.

• Device enumeration in discover``and ``Scanner corrected. Fixes #211

• Updated documentation about scanning filters.

• Added workaround for isScanning attribute added in macOS 10.13. Fixes #234.

0.6.4 (2020-05-20)

Fixed

• Fix for bumpversion usage

0.6.3 (2020-05-20)

Added

• Building and releasing from Github Actions

Removed

• Building and releasing on Azure Pipelines

0.6.2 (2020-05-15)

Added

• Added disconnection_callback functionality for Core Bluetooth (#184 & #186)

• Added requirements.txt

Fixed

• Better cleanup of Bluez notifications (#154)

• Fix for read_gatt_char in Core Bluetooth (#177)

• Fix for is_disconnected in Core Bluetooth (#187 & #185)

• Documentation fixes

0.6.1 (2020-03-09)

Fixed

• Including #156, lost notifications on macOS backend, which was accidentally missed on previous release.

0.6.0 (2020-03-09)

• New Scanner object to allow for async device scanning.

• Updated txdbus requirement to version 1.1.1 (Merged #122)

• Implemented write_gatt_descriptor for Bluez backend.

• Large change in Bluez backend handling of Twisted reactors. Fixes #143

• Modified set_disconnect_callback to actually call the callback as a callback. Fixes #108.

• Added another required parameter to disconnect callbacks.

• Added Discovery filter option in BlueZ backend (Merged #124)

• Merge #138: comments about Bluez version check.

• Improved scanning data for macOS backend. Merge #126.

• Merges #141, a critical fix for macOS.

• Fix for #114, write with response on macOS.

• Fix for #87, DIctionary changes size on .NET backend.

• Fix for #127, uuid or str on macOS.

• Handles str/uuid for characteristics better.

• Merge #148, Run .NET backend notifications on event loop instead of main loop.

• Merge #146, adapt characteristic write log to account for WriteWithoutResponse on macOS.

• Fix for #145, Error in cleanup on Bluez backend.

• Fix for #151, only subscribe to BlueZ messages on DBus. Merge #152.

• Fix for #142, Merge #144, Improved scanning for macOS backend.

• Fix for #155, Merge #156, lost notifications on macOS backend.

• Improved type hints

• Improved error handling for .NET backend.

• Documentation fixes.

0.5.1 (2019-10-09)

• Active Scanning on Windows, #99 potentially solving #95

• Longer timeout in service discovery on BlueZ

• Added timeout to constructors and connect methods

• Fix for get_services on macOS. Relates to #101

• Fixes for disconnect callback on BlueZ, #86 and #83

• Fixed reading of device name in BlueZ. It is not readable as regular characteristic. #104

• Removed logger feedback in BlueZ discovery method.

• More verbose exceptions on macOS, #117 and #107

0.5.0 (2019-08-02)

• macOS support added (thanks to @kevincar)

• Merged #90 which fixed #89: Leaking callbacks in BlueZ

• Merged #92 which fixed #91, Prevent leaking of DBus connections on discovery

• Merged #96: Regex patterns

• Merged #86 which fixed #83 and #82

• Recovered old .NET discovery method to try for #95

• Merged #80: macOS development

0.4.3 (2019-06-30)

• Fix for #76

• Fix for #69

• Fix for #74

• Fix for #68

• Fix for #70

• Merged #66

0.4.2 (2019-05-17)

• Fix for missed part of PR #61.

0.4.1 (2019-05-17)

• Merging of PR #61, improvements and fixes for multiple issues for BlueZ backend

• Implementation of issue #57

• Fixing issue #59

• Documentation fixes.

0.4.0 (2019-04-10)

• Transferred code from the BleakUWPBridge C# support project to pythonnet code

• Fixed BlueZ >= 5.48 issues regarding Battery Service

• Fix for issue #55

0.3.0 (2019-03-18)

• Fix for issue #53: Windows and Python 3.7 error

• Azure Pipelines used for CI

0.2.4 (2018-11-30)

• Fix for issue #52: Timing issue getting characteristics

• Additional fix for issue #51.

• Bugfix for string method for BLEDevice.

0.2.3 (2018-11-28)

• Fix for issue #51: dpkg-query not found on all Linux systems

0.2.2 (2018-11-08)

• Made it compliant with Python 3.5 by removing f-strings

0.2.1 (2018-06-28)

• Improved logging on .NET discover method

• Some type annotation fixes in .NET code

0.2.0 (2018-04-26)

• Project added to Github

• First version on PyPI.

• Working Linux (BlueZ DBus API) backend.

• Working Windows (UWP Bluetooth API) backend.

0.1.0 (2017-10-23)

• Bleak created.