1. ROS Melodic (or Noetic)
2. MAVROS
3. AirSim (or plain Gazebo with PX4)

Fluid FSM is built around a client-server architecture with ROS services, where a client requests the server to do something through ROS services. In other words, we (the client) ask the drone (the server) to do operations.

Have a look at Flow and Operations for more details.

1. Make sure you have MAVROS installed and PX4 and gazebo built.

   MAVROS for Noetic: sudo apt install ros-noetic-mavros ros-noetic-mavros-msgs
   then: /opt/ros/noetic/lib/mavros/install_geographiclib_datasets.sh

   PX4: git clone https://github.com/PX4/PX4-Autopilot PX4

   Gazebo needs gstreamer-library: sudo apt-get install libgstreamer-plugins-base1.0-dev

2. Clone fluid into your catkin workspace in the src-folder.

3. Run source devel/setup.bash and catkin build at root of the catkin workspace.

4. Start Airsim. If you're using gazebo and PX4, start both by running make px4_sitl gazebo from the PX4 folder.

5. Start fluid server: roslaunch fluid simulator.launch.

6. Start your client.

There are some example clients in the src/examples folder.

1. Clone fluid into the catkin workspace on the drone.
2. Run source devel/setup.bash and catkin build at root of the catkin workspace.
3. Start fluid server via the roslaunch file: roslaunch fluid pixhawk.launch.
4. Launch your client node.

You have to use ROS services in order to communicate with the state machine. Have a look at the python and C++ examples in the src/examples folder.