70 lines
2.3 KiB
ReStructuredText
70 lines
2.3 KiB
ReStructuredText
Developing Bluetooth Applications
|
|
#################################
|
|
|
|
Initialization
|
|
**************
|
|
|
|
The Bluetooth subsystem is initialized using the :c:func:`bt_enable()`
|
|
function. The caller should ensure that function succeeds by checking
|
|
the return code for errors. If a function pointer is passed to
|
|
:c:func:`bt_enable()`, the initialization happens asynchronously, and the
|
|
completion is notified through the given function.
|
|
|
|
Bluetooth Application Example
|
|
*****************************
|
|
|
|
A simple Bluetooth beacon application is shown below. The application
|
|
initializes the Bluetooth Subsystem and enables non-connectable
|
|
advertising, effectively acting as a Bluetooth Low Energy broadcaster.
|
|
|
|
.. literalinclude:: ../../../samples/bluetooth/beacon/src/main.c
|
|
:language: c
|
|
:lines: 19-
|
|
:linenos:
|
|
|
|
The key APIs employed by the beacon sample are :c:func:`bt_enable()`
|
|
that's used to initialize Bluetooth and then :c:func:`bt_le_adv_start()`
|
|
that's used to start advertising a specific combination of advertising
|
|
and scan response data.
|
|
|
|
Testing with QEMU
|
|
*****************
|
|
|
|
It's possible to test Bluetooth applications using QEMU. In order to do
|
|
so, a Bluetooth controller needs to be exported from the host OS (Linux)
|
|
to the emulator.
|
|
|
|
Using Host System Bluetooth Controller in QEMU
|
|
==============================================
|
|
|
|
The host OS's Bluetooth controller is connected to the second QEMU
|
|
serial line using a UNIX socket. This socket employs the QEMU option
|
|
:literal:`-serial unix:/tmp/bt-server-bredr`. This option is already
|
|
added to QEMU through :makevar:`QEMU_EXTRA_FLAGS` in most Bluetooth
|
|
sample Makefiles' and made available through the 'run' make target.
|
|
|
|
On the host side, BlueZ allows to export its Bluetooth controller
|
|
through a so-called user channel for QEMU to use:
|
|
|
|
#. Make sure that the Bluetooth controller is down
|
|
|
|
#. Use the btproxy tool to open the listening UNIX socket, type:
|
|
|
|
.. code-block:: console
|
|
|
|
$ sudo tools/btproxy -u
|
|
Listening on /tmp/bt-server-bredr
|
|
|
|
#. Choose one of the Bluetooth sample applications located in
|
|
:literal:`samples/bluetooth`.
|
|
|
|
#. To run Bluetooth application in QEMU, type:
|
|
|
|
.. code-block:: console
|
|
|
|
$ make run
|
|
|
|
Running QEMU now results in a connection with the second serial line to
|
|
the :literal:`bt-server-bredr` UNIX socket, letting the application
|
|
access the Bluetooth controller.
|