This is a workaround for the write timeout that we have seen for some host computers trying to flash the firmware. We don't know the root cause of the problem but we do observed the following: - For blocking writes with timeout (Pyserial write_timeout=0.5): write() throws SerialTimeoutException. In systrace we see that the select() call after write waiting for the write to be finished hangs and finally times out. - For blocking writes without timeout (Pyserial write_timeout=None): write() hangs indefinitely. In systrace we see that the select() call after write waiting for the write to be finished hangs. - For non-blocking writes: write() works but flush() hangs. In systrace we see that ioctl(fd, TCSBRK, 1) which is (correctly) triggered by termios tcdrain hangs. Inspecting USB traffic using usbmon, we can see that the data which is written actually seems to be sent and looking at responses from the Pixhawk bootloader and the timings it looks like all the data has arrived. This workaround uses non-blocking writes without flushing and this seemed to prevent the issue from happening so far. Debugging was done in collaboration with Beat Küng and David Sidrane.
PX4 Drone Autopilot
This repository holds the PX4 flight control solution for drones, with the main applications located in the src/modules directory. It also contains the PX4 Drone Middleware Platform, which provides drivers and middleware to run drones.
- Official Website: http://px4.io (License: BSD 3-clause, LICENSE)
- Supported airframes (portfolio):
- Multicopters
- Fixed wing
- VTOL
- many more experimental types (Rovers, Blimps, Boats, Submarines, etc)
- Releases: Downloads
PX4 Users
The PX4 User Guide explains how to assemble supported vehicles and fly drones with PX4. See the forum and chat if you need help!
PX4 Developers
This Developer Guide is for software developers who want to modify the flight stack and middleware (e.g. to add new flight modes), hardware integrators who want to support new flight controller boards and peripherals, and anyone who wants to get PX4 working on a new (unsupported) airframe/vehicle.
Developers should read the Guide for Contributions. See the forum and chat if you need help!
Weekly Dev Call
The PX4 Dev Team syncs up on a weekly dev call.
Note
The dev call is open to all interested developers (not just the core dev team). This is a great opportunity to meet the team and contribute to the ongoing development of the platform. It includes a QA session for newcomers. All regular calls are listed in the Dronecode calendar.
Maintenance Team
- Project: Founder - Lorenz Meier, Architecture: Daniel Agar
- Communication Architecture
- UI / UX
- Multicopter Flight Control
- VTOL Flight Control
- Fixed Wing Flight Control
- Racers - Matthias Grob
- OS / drivers - David Sidrane
- UAVCAN / Industrial - Pavel Kirienko
- State Estimation - James Goppert, Paul Riseborough
- Vision based navigation
- Obstacle Avoidance - Martina Rivizzigno
- Snapdragon
- Intel Aero
- Raspberry Pi / Navio - Beat Kueng
- Airmind MindPX / MindRacer - Henry Zhang
- RTPS/ROS2 Interface - Nuno Marques
See also About Us (px4.io) and the contributors list (Github).
Supported Hardware
This repository contains code supporting these boards:
- Snapdragon Flight
- Intel Aero
- Raspberry PI with Navio 2
- Parrot Bebop 2
- FMUv2.x
- FMUv3.x Pixhawk 2
- FMUv4.x
- FMUv5.x (ARM Cortex M7)
- Airmind MindPX V2.8
- Airmind MindRacer V1.2
- Bitcraze Crazyflie 2.0
Additional information about supported hardware can be found in PX4 user Guide > Autopilot Hardware.
Project Roadmap
A high level project roadmap is available here.