Nuno Marques 044688f8f8 fix(windows-sitl): unblock MSVC and MinGW Windows SITL build
Two compiler-portability fixes that the Windows SITL CI matrix flagged:

* MSVC (px4_parameters.hpp): switch the generated parameters_volatile
  and parameters_readonly arrays from a C-style `T arr[] = {}` to
  `std::array<T, N>`. The C form is a GCC/Clang extension; MSVC
  rejects a zero-size array with C2466 ("cannot allocate an array of
  constant size 0"). px4_sitl has no volatile or readonly params, so
  both arrays land at size 0 and the build fails at line 11302 of
  the generated header. std::array<T, 0> is standard, supports the
  existing range-for in parameters_common.cpp, and keeps the storage
  identical for non-empty boards.

* MinGW (windows/runtime/init.cpp): drop the `extern` keyword from the
  three g_usleep_* globals. With an initializer present, `extern T x =
  v;` is a definition, and GCC under -Wextra -Werror flags it as
  ``initialized and declared 'extern'``. The matching `extern T x;`
  declarations stay in windows_shim/unistd.h; we wrap the definitions
  in `extern "C" { ... }` so the C linkage the inline shim relies on
  is preserved.

Local Ninja+MSVC build of build/px4_sitl_default --target px4
succeeds; bin/px4.exe is produced (10.8 MB).

Signed-off-by: Nuno Marques <n.marques21@hotmail.com>
2026-05-07 17:24:40 -07:00

PX4 Autopilot

The autopilot stack the industry builds on.

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About

PX4 is an open-source autopilot stack for drones and unmanned vehicles. It supports multirotors, fixed-wing, VTOL, rovers, and many more experimental platforms from racing quads to industrial survey aircraft. It runs on NuttX, Linux, and macOS. Licensed under BSD 3-Clause.

Why PX4

Modular architecture. PX4 is built around uORB, a DDS-compatible publish/subscribe middleware. Modules are fully parallelized and thread safe. You can build custom configurations and trim what you don't need.

Wide hardware support. PX4 runs on a wide range of autopilot boards and supports an extensive set of sensors, telemetry radios, and actuators through the Pixhawk ecosystem.

Developer friendly. First-class support for MAVLink and DDS / ROS 2 integration. Comprehensive SITL simulation, hardware-in-the-loop testing, and log analysis tools. An active developer community on Discord and the weekly dev call.

Vendor neutral governance. PX4 is hosted under the Dronecode Foundation, part of the Linux Foundation. Business-friendly BSD-3 license. No single vendor controls the roadmap.

Supported Vehicles

Multicopter
Multicopter
Fixed Wing
Fixed Wing
VTOL
VTOL
Rover
Rover

…and many more: helicopters, autogyros, airships, submarines, boats, and other experimental platforms. These frames have basic support but are not part of the regular flight-test program. See the full airframe reference.

Try PX4

Run PX4 in simulation with a single command. No build tools, no dependencies beyond Docker:

docker run --rm -it -p 14550:14550/udp px4io/px4-sitl:latest

Open QGroundControl and fly. See PX4 Simulation Quickstart for more options.

Build from Source

git clone https://github.com/PX4/PX4-Autopilot.git --recursive
cd PX4-Autopilot
make px4_sitl

Note

See the Development Guide for toolchain setup and build options.

Documentation & Resources

Resource Description
User Guide Build, configure, and fly with PX4
Developer Guide Modify the flight stack, add peripherals, port to new hardware
Airframe Reference Full list of supported frames
Autopilot Hardware Compatible flight controllers
Release Notes What's new in each release
Contribution Guide How to contribute to PX4

Community

Contributing

We welcome contributions of all kinds — bug reports, documentation, new features, and code reviews. Please read the Contribution Guide to get started.

Citation

If you use PX4 in academic work, please cite it. BibTeX:

@software{px4_autopilot,
  author    = {Meier, Lorenz and {The PX4 Contributors}},
  title     = {{PX4 Autopilot}},
  publisher = {Zenodo},
  doi       = {10.5281/zenodo.595432},
  url       = {https://px4.io}
}

The DOI above is a Zenodo concept DOI that always resolves to the latest release. For a version-pinned citation, see the Zenodo record or our CITATION.cff.

Governance

The PX4 Autopilot project is hosted by the Dronecode Foundation, a Linux Foundation Collaborative Project. Dronecode holds all PX4 trademarks and serves as the project's legal guardian, ensuring vendor-neutral stewardship — no single company owns the name or controls the roadmap. The source code is licensed under the BSD 3-Clause license, so you are free to use, modify, and distribute it in your own projects.

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