Integrating Custom Sensor Data into PX4 for Onboard Navigation – Best Practices?

[Grayson]

Hi everyone,

I’m currently working on integrating a custom environmental sensor (providing wind speed, direction, and barometric pressure) into a PX4-based system onboard a fixed-wing UAV. The sensor communicates via UART and sends data at 10Hz. I’d like to feed this data into the estimator (likely using EKF2) to improve local wind awareness and altitude estimation.

I’ve reviewed the uORB documentation and am comfortable creating a custom module to publish sensor data as a uORB topic. However, I’m trying to understand the best practice for ensuring that EKF2 or other modules can consume and benefit from this information. Specifically:

• Is there an existing uORB topic structure for environmental data that EKF2 can subscribe to, or would I need to modify the estimator itself?
• Are there any considerations for timestamp synchronization and data latency when feeding in this kind of auxiliary sensor data?
• Would it be preferable to wrap this into a custom MAVLink message for logging/ground station purposes, or keep it strictly internal to PX4 via uORB?
• Finally, if anyone has experience implementing similar functionality (e.g., integrating pitot tube or wind sensors not natively supported), I’d really appreciate any example repos or code snippets.

Question about Offboard Mode for Fixed Wing Vehicles in PX4 and ROS2 for Multi-Vehicle Tracking

Hello, I am working on a multi-vehicle setup using PX4 and ROS2, where my goal is for one fixed wing aircraft to follow another. I have been using the trajectory setpoint message type to achieve this. However, during my research, I came across the statement: “Offboard mode is not supported by Fixed Wing vehicles. It is supported for Copter and VTOL vehicles.” I would like to confirm the validity of this statement. Is it accurate that Fixed Wing vehicles cannot use Offboard mode in PX4? If t…

I’d like to keep the system modular and maintain compatibility with future PX4 updates, so I’d prefer not to modify the core estimator code unless absolutely necessary. While my primary focus is on UAV systems, I’m also exploring automation workflows (like uipath training in pune) to enhance development pipelines and streamline integration testing—so maintaining clean, updatable architecture in PX4 is a priority.

Any guidance or pointers to relevant examples would be greatly appreciated!

Thanks in advance,
Grayson

[JulianOes]

Let me tag @bresch here. He could know how wind could be fed into the EKF.

@Grayson

Would it be preferable to wrap this into a custom MAVLink message for logging/ground station purposes, or keep it strictly internal to PX4 via uORB?

That’s up to you. Whatever fits in available MAVLink messages, you might was well use. Anything on top, depends on whether you need it as realtime feedback, or just later from the log.