PX4 Dev Call: March 18, 2020

March 18th, 2020


  • Status update by component/project
  • Roadmap, and Release discussion
  • Community Q&A
  • In-Depth discussions

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Meeting ID: 946 175 205
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Call in using your phone, find your local number: https://zoom.us/u/aetSYKbiMF

Component update


Flight Testing

  • :cloud_with_lightning_and_rain: The weather condition is still not suitable for flight; it looks like it will be raining all week. There were multiple indoor tests conducted.
  • :beetle: PR #14168 contains a bug, and that’s why it didn’t arm in testing.

System Architecture

OS / NuttX

  • :zap: F4 and F7 DMA changes were upstreamed to NuttX and are pending testing.
  • :rocket: UAVCAN SocketCAN driver was updated in NuttX, and we can start testing that It’s still sending 0.9 UAVCAN messages above the transport layer.


  • :gear: UAVCAN Sensor drivers PR
  • :running_woman: Big driver refactors for better reusability and scalability.


  • :memo: Significant improvements in the preflight checks user experience.


  • :broom: There are a lot of smaller cleanups going on.
  • :zap: The yaw estimator was merged.


  • :speech_balloon: Further discussion needed on how to handle the optional configuration of FMUv2 without VTOL

Fixed Wing

  • :triangular_ruler: @sfuhrer working on bringing the fixed-wing position controller into the local frame
  • :rocket: @Jaeyoung-Lim has catapult launch working in simulation, but it’s not part of CI yet.
  • :warning: Fixed-wing is still not supported by MAVSDK.
  • :warning: MAVSDK CI tests cannot do fixed-wing yet.


  • :helicopter: Only outdoor testing open PR 14326
  • :surfing_man:‍♂ Hover thrust estimator testable by parameter PR 14378
  • :+1: We should have this for the release, still pending a fix of the integrator problem PR #14212


  • :bulb: Improved testing ready to be merged, running in CI, giving better feedback
  • :pushpin: Next step: extend to automated real-world testing


  • :hammer_and_wrench: @TSC21 porting avoidance to ROS2


  • :sparkles: New MAVROS support for the bezier interface that was later added to the flight control. @jkflying


  • :warning: @Jaeyoung-Lim MacOS homebrew has conflicting dependencies and is currently broken. There will be a fix soon.

Roadmap, and Release discussion

  • PX4 v1.11 Release Notes
  • Beta flight-testing.

Discussions about when to cut a feature freeze. @dagar is concerned about e.g., the CPU load on some older resource-constrained boards. These might require additional driver “features” to improve performance. It’s a fine line between freezing and slipping the release. We should have a low barrier beta announced, but make sure the testers don’t have a horrific experience.

The hover thrust estimator could be enabled by default in the beta, and in case we still find any significant issues, we could always disable it for the release.

In-Depth discussions


Idea making C++ standard library available on the MCU might also help for UAVCAN 1.0. But that’s a big task. The proposition to get existing unit tests that are now SITL test over to gtest. What’s necessary on the MCU is a HITL style integration test with realistic timing and all drivers still running in the background with constant monitoring of all the resources during flight.

@dagar How do we handle the optional configuration of FMUv2 without VTOL? (from above)
It’s not currently possible to have a VTOL only/enabled build for FMUv2. We’d need a way to strip out unused airframes to make an FMUv2 VTOL build, @LorenzMeier seems to have some ideas to do that.

Community Q&A


  • Difference between Main and AUX output, he wants to have his Octocopter running with DSHOT?
  • Is there support for brushed motor output to control a non-BLDC motor? @dagar offered pointers offline
  • The idea about redundant RC values via duplicate MAVLink. We have to be careful about link differences e.g., latency. It might require a high complexity, and that could induce more failure cases than what we have right now.
  • In mission mode or autonomous landing, there’s ALT1 and ALT2 to slow down the landing. Questions about how it works and how to configure not to land too slow or too fast. @MaEtUgR offered offline suggestions.

PX4 Dev Summit

by @rroche

Survey about postponing, canceling for this year?
We canceled until further notice. We’ll do our best to have an in-person event, and we’ll wait that out no matter how long it takes.

Errata and Feedback

Let me know below if I failed to capture anything the right way, and if there are any updates, or you have feedback on the call format.

about the redundant link issue that was talked on call.
I see that there is already singing mehcanision:
that can be used

1 Like

Thanks to everyone who sent their notes and contributed to the call this week. :tada: