Direct-BT LE and BREDR Library + Tiny Bluetooth LE Library ========================================================== Git Repository ============== This project's canonical repositories is hosted on [Gothel Software](https://jausoft.com/cgit/direct_bt.git/). Goals ============ This project aims to create a clean, modern and easy to use API for [Bluetooth LE and BREDR](https://www.bluetooth.com/specifications/bluetooth-core-specification/), fully accessible through C++, Java and other languages. Version 2 ========== Starting with version 2.1.0, the *TinyB* Java API has been refactored to support all new features of its new *Direct-BT* implementation. As of today, the *TinyB* Java API comprises two implementations, *Direct-BT* and *TinyB*. Direct-BT ---------- *Direct-BT* provides direct [Bluetooth LE and BREDR](https://www.bluetooth.com/specifications/bluetooth-core-specification/) programming, offering robust high-performance support for embedded & desktop with zero overhead via C++ and Java. *Direct-BT* supports a fully event driven workflow from device discovery to GATT programming, using its platform agnostic HCI and GATT/L2CAP client-side protocol implementation. [AdapterStatusListener](https://jausoft.com/projects/direct_bt/build/documentation/cpp/html/classdirect__bt_1_1AdapterStatusListener.html) allows listening to adapter changes and device discovery and [GATTCharacteristicListener](https://jausoft.com/projects/direct_bt/build/documentation/cpp/html/classdirect__bt_1_1GATTCharacteristicListener.html) to GATT indications and notifications. *Direct-BT* may be utilized via its [C++ API](https://jausoft.com/projects/direct_bt/build/documentation/cpp/html/index.html) or via the refactored TinyB [Java API](https://jausoft.com/projects/direct_bt/build/documentation/java/html/index.html). *Direct-BT* is exposed via the following native libraries - *libdirect_bt.so* for the core C++ implementation. - *libjavadirect_bt.so* for the Java binding. *Direct-BT* is C++17 conform and shall upgrade towards C++20 when widely available on all target platforms. You will find a detailed overview of *Direct-BT* in the doxygen generated [C++ API doc of its *direct_bt* namespace](https://jausoft.com/projects/direct_bt/build/documentation/cpp/html/namespacedirect__bt.html#details). Some more elaboration on the implementation and its status > The host-side of HCI, L2CAP etc is usually implemented within the OS, e.g. *Linux/BlueZ* Kernel. > These layers communicate with the actual BT controller and the user application, acting as the middleman. > > *Direct-BT* offers packet types and handler facilities for HCI, L2CAP, ATT-PDU and GATT (as well to *Linux/BlueZ-Mngr[1]*) > to communicate with these universal host-side Bluetooth layers and hence to reach-out to devices. > > Currently only the master/client mode is supported to work with BT devices, as well as LE w/o *LE Secure Connections*. > > Work on *LE Secure Connections* is in progress and BREDR (non LE, or classic mode) is planned and prepared for. > > [1] *Linux/BlueZ-Mngr* is still used for adapter configuration and shall be removed to support universal platforms, > implementing the Bluetooth host-side protocols. Since *Direct-BT* is not using a 3rd party Bluetooth client library or daemon/service, they should be disabled to allow operation without any interference. To disable the *BlueZ* D-Bus userspace daemon *bluetoothd* via systemd, you may use the following commands. ``` systemctl stop bluetooth systemctl disable bluetooth systemctl mask bluetooth ``` *Direct-BT* is the new implementation as provided by [Zafena ICT](https://ict.zafena.se) and [Gothel Software](https://jausoft.com/). TinyB ----- *TinyB* exposes the BLE GATT API for C++, Java and other languages, using *BlueZ* over DBus. *TinyB* does not expose the BREDR API. *TinyB* is exposed via the following native libraries - *libtinyb.so* for the core C++ implementation. - *libjavatinyb.so* for the Java binding. *TinyB* is the original implementation of the TinyB project by Intel. TinyB and Direct-BT ------------------- Pre version 2.0.0 D-Bus implementation details of the Java[tm] classes of package *tinyb* has been moved to *tinyb.dbus*. The *tinyb.jar* jar file has been renamed to *tinyb2.jar*, avoiding conflicts. General interfaces matching the original implementation and following [BlueZ API](http://git.kernel.org/cgit/bluetooth/bluez.git/tree/doc/) were created in package *org.tinyb*. *org.tinyb.BluetoothFactory* provides a factory to instantiate the initial root *org.tinyb.BluetoothManager*, either using *Tiny-B*, the original D-Bus implementation, or *Direct-BT*, the direct implementation. *TinyB*'s C++ namespace and implementation kept mostly unchanged. The new Java interface of package *org.tinyb* has been kept mostly compatible, however, changes were required to benefit from *Direct-BT*'s implementation. *since 2.x* version tags have been added to the Java interface specification for clarity. API Documentation ============ Up to date API documentation can be found: * [Brief overview of *direct_bt*](https://jausoft.com/projects/direct_bt/build/documentation/cpp/html/namespacedirect__bt.html#details). * [C++ API Doc](https://jausoft.com/projects/direct_bt/build/documentation/cpp/html/index.html). * [Java API Doc](https://jausoft.com/projects/direct_bt/build/documentation/java/html/index.html). * [Jau C++ Standalone API Doc](https://jausoft.com/projects/jaucpp/build/documentation/cpp/html/index.html). A guide for getting started with *Direct-BT* on C++ and Java may follow up. Examples ============ *Direct-BT* [C++ examples](https://jausoft.com/projects/direct_bt/build/documentation/cpp/html/examples.html) are available, [dbt_scanner10.cpp](https://jausoft.com/projects/direct_bt/build/documentation/cpp/html/dbt_scanner10_8cpp-example.html) demonstrates the event driven and multithreading workflow. *Direct-BT* [Java examples](https://jausoft.com/projects/direct_bt/build/documentation/java/html/examples.html) are availble, [DBTScanner10.java](https://jausoft.com/projects/direct_bt/build/documentation/java/html/DBTScanner10_8java-example.html) demonstrates the event driven and multithreading workflow - matching *dbt_scanner10.cpp*. A guide for getting started with *TinyB* on Java is available from Intel: https://software.intel.com/en-us/java-for-bluetooth-le-apps. The hellotinyb example uses a [TI Sensor Tag](http://www.ti.com/ww/en/wireless_connectivity/sensortag2015/?INTC=SensorTag&HQS=sensortag) from which it reads the ambient temperature. You have to pass the MAC address of the Sensor Tag as a first parameter to the program. Supported Platforms =================== The following **platforms** are tested and hence supported **Debian 10 Buster (GNU/Linux)** - amd64 (validated, Generic) - arm64 (validated, Raspberry Pi 3+ and 4) - arm32 (validated, Raspberry Pi 3+ and 4) **Debian 11 Bullseye (GNU/Linux)** - amd64 (validated, Generic) - arm64 (should work, Raspberry Pi 3+ and 4) - arm32 (should work, Raspberry Pi 3+ and 4) The following **Bluetooth Adapter** were tested * Intel Bluemoon Bluetooth Adapter * CSR Bluetooth Adapter (CSR8510,..) * Raspberry Pi Bluetooth Adapter (BCM43455 on 3+, 4) After we have resolved the last Linux/Bluez dependency in DBTManager for BT adapter configuration, we should be capable working on other systems than GNU/Linux. Build Status ============ *Will be updated* Building Binaries ========================= The project requires CMake 3.13+ for building and a Java JDK >= 11. This project also uses the [Jau C++ Library](https://jausoft.com/cgit/jaucpp.git/about/) as a git submodule, which has been extracted earlier from this project to better encapsulation and allow general use. *TinyB* requires GLib/GIO 2.40+. It also requires *BlueZ* with GATT profile activated, which is currently experimental (as of *BlueZ* 5.37), so you might have to run bluetoothd with the -E flag. For example, on a system with systemd (Fedora, poky, etc.) edit the bluetooth.service file (usually found in /usr/lib/systemd/system/ or /lib/systemd/system) and append -E to ExecStart line, restart the daemon with systemctl restart bluetooth. *Direct-BT* does not require GLib/GIO nor shall the *BlueZ* userspace service *bluetoothd* be active for best experience. To disable the *bluetoothd* service using systemd: ~~~~~~~~~~~~~~~~~~~~~~~~~~~{.sh} systemctl stop bluetooth systemctl disable bluetooth systemctl mask bluetooth ~~~~~~~~~~~~~~~~~~~~~~~~~~~ Installing build dependencies on Debian (10 or 11): ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.sh} apt install git apt install build-essential g++ gcc libc-dev libpthread-stubs0-dev apt install libunwind8 libunwind-dev apt install libglib2.0 libglib2.0-0 libglib2.0-dev apt install openjdk-11-jdk openjdk-11-jre apt install cmake cmake-extras extra-cmake-modules pkg-config apt install doxygen graphviz ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ For a generic build use: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~{.sh} CPU_COUNT=`getconf _NPROCESSORS_ONLN` git clone --recurse-submodules https://jausoft.com/cgit/direct_bt.git cd direct_bt mkdir build cd build cmake -DBUILDJAVA=ON -DBUILDEXAMPLES=ON -DBUILD_TESTING=ON .. make -j $CPU_COUNT install test doc ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The install target of the last command will create the include/ and lib/ directories with a copy of the headers and library objects respectively in your build location. Note that doing an out-of-source build may cause issues when rebuilding later on. Our cmake configure has a number of options, *cmake-gui* or *ccmake* can show you all the options. The interesting ones are detailed below: Changing install path from /usr/local to /usr ~~~~~~~~~~~~~ -DCMAKE_INSTALL_PREFIX=/usr ~~~~~~~~~~~~~ Building debug build: ~~~~~~~~~~~~~ -DDEBUG=ON ~~~~~~~~~~~~~ Building debug and instrumentation (sanitizer) build: ~~~~~~~~~~~~~ -DDEBUG=ON -DINSTRUMENTATION=ON ~~~~~~~~~~~~~ Using clang instead of gcc: ~~~~~~~~~~~~~ -DCMAKE_C_COMPILER=/usr/bin/clang -DCMAKE_CXX_COMPILER=/usr/bin/clang++ ~~~~~~~~~~~~~ Cross-compiling on a different system: ~~~~~~~~~~~~~ -DCMAKE_CXX_FLAGS:STRING=-m32 -march=i586 -DCMAKE_C_FLAGS:STRING=-m32 -march=i586 ~~~~~~~~~~~~~ To build Java bindings: ~~~~~~~~~~~~~ -DBUILDJAVA=ON ~~~~~~~~~~~~~ To not build the *TinyB* implementation: ~~~~~~~~~~~~~ -DSKIP_TINYB=ON ~~~~~~~~~~~~~ To build examples: ~~~~~~~~~~~~~ -DBUILDEXAMPLES=ON ~~~~~~~~~~~~~ To build documentation run: ~~~~~~~~~~~~~ make doc ~~~~~~~~~~~~~ Changes ============ **2.1.30 Early *Direct-BT* Maturity (Bluetooth LE)** * TODO * Passed GCC all warnings, compile clean * Passed GCC sanitizer runtime checks * Using extracted *Jau C++ Support Library*, enhanced encapsulation * Passed valgrind's memcheck, helgrind and drd validating no memory leak nor data race or deadlock using dbt_scanner10 * Added native de-mangled backtrace support using *libunwind* and and *abi::__cxa_demangle* * Reaching robust implementation state of *Direct-BT*, including recovery from L2CAP transmission breakdown on Raspberry Pi. * Resolved race conditions on rapid device discovery and connect, using one thread per device. * API documentation with examples * Tested on GNU/Linux x86_64, arm32 and arm64 with native and Java examples. * Tested on Bluetooth Adapter: Intel, CSR and Raspberry Pi * Almost removed non-standard *Linux/BlueZ-Mngr* kernel dependency using the universal HCI protocol, remaining portion configures the adapter. **2.0.0** * Java D-Bus implementation details of package 'tinyb' moved to *tinyb.dbus*. * The *tinyb.jar* jar file has been renamed to *tinyb2.jar*, avoiding conflicts. * General interfaces matching the original implementation and following [BlueZ API](http://git.kernel.org/cgit/bluetooth/bluez.git/tree/doc/device-api.txt) were created in package *org.tinyb*. * Class *org.tinyb.BluetoothFactory* provides a factory to instantiate the initial root *org.tinyb.BluetoothManager*, either using the original D-Bus implementation or an alternative implementation. * C++ namespace and implementation kept unchanged. **0.5.0** * Added notifications API * Capitalized RSSI and UUID properly in Java * Added JNI Helper classes for managing lifetime of JNIEnv and Global Refences **0.4.0** * Added asynchronous methods for discovering BluetoothObjects Common issues ============ If you have any issues, please go through the [Troubleshooting Guide](TROUBLESHOOTING.md). If the solution is not there, please search for an existing issue in our [Bugzilla DB](https://jausoft.com/bugzilla/describecomponents.cgi?product=Direct-BT), please [contact us](https://jausoft.com/) for a new bugzilla account via email to Sven Gothel . Contributing to TinyB / Direct-BT =================================== You shall agree to Developer Certificate of Origin and Sign-off your code, using a real name and e-mail address. Please check the [Contribution](CONTRIBUTING.md) document for more details.