Some simple examples were created by the HoverGames team. They are available on our NXP HoverGames GitHub in the Tutorials repository. You can place these examples in the
src/examples folder of the PX4 firmware and edit the
boards/nxp/fmuk66-v3/default.cmake file to include these examples in the build process.
The PX4 firmware already includes a few example applications, some of which are similar to the examples created for HoverGames. They can be found under the
src/examples folder and should be included by default on most builds.
The PX4 Developer Guide also includes a "getting started" page for writing your first PX4 module. This is also based on some of these examples. It explains some of the basics of creating a new module, building your new code and interacting with it from the console. It also gives an introduction to using uORB, the middleware layer that allows you to communicate with other modules.
It is strongly recommended that you start with these examples and then slowly start exploring other parts of the software. The PX4 Developer Guide is a good place to get information and you can always ask your questions on the PX4 Discuss or Slack.
Example software for other components used in the HoverGames is available on their own pages. You can find them by scrolling down in the menu on the left. They are listed under "complimentary components".