eProsima Fast DDS is a C++ implementation of the Object Management Group's (OMG) Data Distribution Service (DDS) specification and the Real Time Publish Subscribe (RTPS) protocol.
Fast DDS enables an RTPS/DDS interface that allows PX4 uORB topics to be shared with offboard components that participate in same DDS domain, including robotics and simulator tools. In particular, Fast DDS is the default middleware implementation for Robot Operating System 2 (ROS 2), and is essential for integrating PX4 with ROS2.
This topic explains how to install Fast DDS and Fast-RTPS-Gen to use in the PX4 build system and with the microRTPS bridge.
:::note
You do not have to install Fast DDS if you have ROS 2 Dashing (Ubuntu 18.04) or ROS 2 Foxy (Ubuntu 20.04) installed, as it comes included with the default base
or desktop
installations through the ros-<distro>-rmw-fastrtps
package.
This means you just need to install Fast-RTPS-Gen and have your ROS 2 environment sourced (source /opt/ros/<distro>/setup.bash
) in order to be able to compile the rtps
targets in the PX4-Autopilot repo.
For ROS2 Galactic and above, one has to install the rmw
implementation through apt
using apt install ros-galactic-rmw-fastrtps
, since the default middleware for Galactic and above is CycloneDDS and the FastDDS middleware doesn't come installed by default.
:::
:::tip Fast DDS is not an essential component of the PX4 Autopilot and should only be installed if you plan to interface the PX4 Autopilot with Fast RTPS/DDS participants. ROS 2 nodes are an example of these, though Fast DDS middleware and C++ implementations are installed by default on ROS 2 Foxy and below, as mentioned above. :::
:::note Fast DDS was previously named FastRTPS (the name was changed in version 2.0.0 as it now includes a full DDS implementation, rather than just the RTPS wire protocol). :::
eProsima Fast DDS requires the following packages to work.
:::note At time of writing you will need to install from source for:
- Ubuntu 18.04: Fast RTPS 1.8.4 (or later) and Fast-RTPS-Gen 1.0.4 (not later!).
- Ubuntu 20.04: Fast DDS 2.0.2 (or later) and Fast-RTPS-Gen 1.0.4 (not later!). :::
:::tip
Remember (again) you only need to install Fast DDS if you are not using ROS 2 and just want to leverage non-ROS2 DDS networks and applications.
If you have ROS 2 installed (and rmw-fasrtps
as its default middleware), you can skip to Fast-RTPS-Gen build and install.
:::
Java is required to build and use eProsima's RTPS/DDS from IDL code generation tool - Fast-RTPS-Gen. Java JDK 11 is recommended, and it is installed through the setup scripts made available in Ubuntu Development Environment.
You also need to install Gradle to build Fast-RTPS-Gen. We recommend you install Gradle via sdkman.
:::warning Do not install Gradle version 7 or higher. The recommended version is 6.3. :::
In order to build Fast DDS you need to install the Foonathan Memory dependency.
git clone https://github.com/eProsima/foonathan_memory_vendor.git
cd foonathan_memory_vendor
mkdir build && cd build
cmake ..
cmake --build . --target install
:::note
If the last step fails, try running the command with the proper user privileges (sudo
).
:::
Clone the project from Github:
$ git clone --recursive https://github.com/eProsima/Fast-DDS.git -b v2.0.2 ~/FastDDS-2.0.2
$ cd ~/FastDDS-2.0.2
$ mkdir build && cd build
If you are on Linux, execute:
$ cmake -DTHIRDPARTY=ON -DSECURITY=ON ..
$ make -j$(nproc --all)
$ sudo make install
This will install Fast DDS to /usr/local
, with secure communications support.
If you need to install to a custom location you can use: -DCMAKE_INSTALL_PREFIX=<path>
.
The following additional arguments can be used when calling CMake:
-DCOMPILE_EXAMPLES=ON
: Compile the examples-DPERFORMANCE_TESTS=ON
: Compile the performance tests
Fast-RTPS-Gen is the Fast RTPS (DDS) IDL code generator tool.
It should be installed after Fast RTPS (DDS) and made sure the fastrtpsgen
application is in your PATH
.
You can check with which fastrtpsgen
.
Then install Fast-RTPS-Gen 1.0.4 (Gradle is required for this):
git clone --recursive https://github.com/eProsima/Fast-DDS-Gen.git -b v1.0.4 ~/Fast-RTPS-Gen \
&& cd ~/Fast-RTPS-Gen \
&& gradle assemble \
&& sudo env "PATH=$PATH" gradle install
:::note Although the binaries are available, we recommend to build and install the code from source, given that the binaries may not come with required components and dependencies in place. :::
The latest binary release of eProsima Fast DDS can be downloaded from the company website.
Documentation on how to do this can be found here: Installation from Binaries on Linux and Installation from Binaries on Windows (eProsima Fast DDS official documentation)
FASTRTPSGEN_DIR
: Root folder where eProsima Fast-RTPS-Gen is installed, usually set to/usr/local
, which is the default installation directory. If the user sets a different install directory in thegradle install
step, it must set this variable to that same directory as well. Otherwise, the code generation step, and consequently, the build of thertps
targets in PX4 will fail.
-
Additional installation information can be found in the official eProsima Fast DDS documentation (from which this topic is derived):