For an example of building an android bluetooth app, see the example folder and its accompanying README file.
There are a handful of ways to run Python on Android. Presently some code has been written for the Python-for-Android build tool, and the code has only been tested using the Kivy Framework. The Kivy framework provides a way to make graphical applications using bluetooth that run on both android and desktop.
An alternative framework is BeeWare. An implementation for BeeWare would likely be very similar to Python-for-Android, if anybody is interested in contributing one. As of 2020, the major task to tackle is making a custom template to embed Java subclasses of the Bluetooth Android interfaces, for forwarding callbacks.
The Python-for-Android backend classes are found in the
bleak.backends.p4android package and are automatically selected when
building with python-for-android or Buildozer,
Kivy's automated build tool.
For one thing, the python-for-android backend has not been fully tested.
Please run applications with adb logcat or buildozer android logcat and
file issues that include the output, so that any compatibility concerns with
devices the developer did not own can be eventually addressed. This backend
was originally authored by @xloem for a project that has mostly wrapped up now,
so it would be good to tag him in the issues.
When fixing issues, often the Android documentation is lacking, and other resources may need to be consulted to find information on various device quirks, such as community developer forums.
Sometimes device drivers will give off new, undocumented error codes.
There is a developing list of these at bleak.backends.p4android.defs.GATT_STATUS_NAMES.
Please add to the list if you find new status codes, which is indicated by a
number being reported instead of a name.
Additionally a few small features are missing. Please file an issue if you need a missing feature, and ideally contribute code, so that soon they will all be implemented.
Two missing features include scanning filters and indications (notifications without replies).
Additionally reading from a characteristic has not been tested at all, as xloem's test device did not provide for this.
On Android, Bluetooth needs permissions for access. These permissions need to be added to the android application in the buildozer.spec file, and are also requested from the user at runtime. This means that enabling bluetooth may not succeed if the user does not accept permissions.
.. automodule:: bleak.backends.p4android.scanner
:members:
.. automodule:: bleak.backends.p4android.client
:members: