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APX4 2.5.0


Please use Auterion Mission Control 1.14.0 or newer with this version of APX4:

New Features


  • Support for Parachutes from Drone Rescue Systems
  • General Flight UX:
    • Three-stage smooth landing in automatic modes -
    • Survey: allow resuming a survey and have gimbal pointing back down
    • Data link fail safe available in all modes
    • Margin for horizontal multi-copter control when prioritizing vertical authority: improves horizontal flight behavior in primarily vertical operations
    • Automatically switch to remote control loss behavior on yaw emergency detection
    • Directional speed constraints for Multicopter
    • Beta/Preview: Basic rover support (please reach out if you are interested to use AEPX4 on ground vehicles)
  • VTOL:
    • Rally Points: Support Multiple Land Approaches for VTOL / FW as on normal landing points
    • Support VTOL missions without takeoff waypoint
    • Smooth orbit approach trajectory , also fixes instances where Orbit altitude was not followed
    • Yaw-less multicopter mixer for use with tiltrotor type vehicles
    • Multicopter hover trust estimator takes into account additional lift on VTOL vehicles
  • Workflows
    • Add support to capture for syncing GPS and image capture to enable high precision survey workflows
  • Peripherals:
    • Battery over voltage protection/handling
    • Allow setting idle throttle on UAVCAN ESCs
    • Support for ADS1115 ADC
    • Enable HITL over UDP
    • Support for INA237 12S power module
    • Actuator endurance test feature
    • Support for radio_status_extension messages


  • All the new features made available in upstream PX4 v1.12 release

What improved

  • General Flight UX:
    • Delay before triggering RTL on critical battery
    • Improved accuracy of yaw emergency trigger
      • Commander: update yaw emergency messaging towards the user
    • Improved accuracy of imbalanced propeller check metric
    • Add support for toggle buttons via RC channels
    • GNSS yaw: handle sensor reset (observed on F9P)
    • Parameterized range setting for hover thrust estimator range
    • rotations: introduce support for ROTATION_PITCH_90_YAW_45
    • Do not re-check feasibility of commenced mission when already in-air
    • Only allow arming in modes that are suitable for take off
    • Required mag used by EKF as mandatory for arming
    • Better user notifications on battery pre-warnings
  • VTOL:
    • TECS: stay in flight phase level if only small altitude changes are demanded
    • Orbit flight behavior improvements
    • Fixed-wing loiter: set yaw setpoint tangentially to loiter
    • VTOL: Tiltrotor: enable hovering in non-zero tilts with forward tilt assist
    • Autotuning improvements for vehicles with slower response like VTOL
    • Don't fly mission land pattern when triggered RTL in hover on VTOL
    • Better airspeed selector messaging and warnings to user
    • front transition: fade out yaw control
    • Don't start Orbit, if radius not in allowed range + increase allowed range
    • Also use VTOL Safe Area feature after after geofence event
    • Prevent interrupting VTOL takeoff when failsafe happens at the same time
    • support alternative pitch setpoint offset in hover for landing
    • Trigger quadchute RTL on airspeed failure also in VTOL takeoff and loiter modes
    • Reset hover thrust when disarmed to prevent wrong estimate from landing affecting flight
  • System:
    • Overhaul of control allocation architecture to support dynamic control allocation (available as preview)
    • Prevent vehicle arm during calibration
    • Increase number of mavlink remote components
    • Check target field in mavlink shell
    • Too early reporting of pre-flight checks
  • Peripherals:
    • UAVCAN battery upgraded to use battery lib to enable taking into account internal resistance parameters
    • power monitor module is started now automatically
    • Point gimbal to neutral on RTL and failsafe
    • Do not trigger/warn user about a navigation failure during sensor calibration
    • Move capture and PPS pins to be Skynode compatible
    • preflight checks: to not require to have a transition switch
    • Stop capturing images on mission exit
    • Gimbal frames wrong when using vmount v1 on v2 input

Resolved Issues

The following bugs have been fixed:

General Flight UX

  • ROI location handled incorrectly
  • GPS loss messaging unclear
  • Immediate rearming after landing cant bypass all checks
  • Unexpected yaw on go-to with altitude change
  • Slow descent on stuck distance sensor
  • Yaw nudging conflicting with weather vane → only allow yaw nudging when weather vane is disabled
  • COMMAND_CANCEL not being handled properly by custom action waypoints
  • position main-state achievable over RC before GPS lock
  • Not switching to hold mode when mission finished
  • False in-ground-effect landing signal on long range distance sensor
  • Thrust step at takeoff
  • Pitch & Roll Oscillations During Go-To Descent
  • Vehicle does not stop properly when paused during a mission but instead it turns around and goes back to where it was paused.
  • Wrong gimbal user input scale
  • Rejected mission can be executed
  • Vehicle not switching to goto immediately when commanded to do so
  • Direction change in Orbit not accepted
  • Vehicle does yaw step on takeoff
  • ROI as part of mission not working
  • Consider vehicle still landed in all cases before motor spool-up is complete
  • Take pictures on takeoff on mission resume
  • Incorrect handling of zero remaining flight time state


  • Tight curve during back-transition on landing
  • automatic approach selection: wrong direction selected
  • wind estimate incorrect after VTOL landing
  • takeoff: loiter sector choice changes after transition to fixed-wing mode
  • tiltrotor vehicles: wrong throttle setpoint during stabilized transition
  • incorrect descend tracking in back-transition
  • wrong manual cimb rate
  • altitude setpoint issues on descend
  • Flight Time Estimator RTL action interferes with active landing
  • safe areas from previous flight used
  • mag bias estimator not operational after landing and re-takeoff
  • Commanded orbit altitude not followed
  • undefined flight path flight path when changing altitude during position flight mode in fixed wing mode


  • Error message when reading old storage formats
  • Corner case that could make vehicle uncontrollable by user until automatic RTL starts
  • Battery failsafe can interfere with time based RTL
  • SD-card file storage failures
  • When using two Power Modules on skynode, only one battery was displayed in AMC
  • Fix sensors not starting up in some cases
  • IMU coning warnings
  • Camera capture message do not arrive in low bandwidth link
  • Glitch in startup sound


  • Iridium modem can't be connected after boot
  • Map Camera Viewpoint Cone / Sensor Point of Interest Incorrect
  • Dshot Voltage reading jumps to 0 / UAVCAN ESC reported even if there are no UAVCAN ESCs
  • INA226 Power monitor reports wrong current
  • sdp3x: fix situation when wire/contact gets disconnected SDP3X sensor was not able to reconfigure.
+ several other bug-fixes

Fixed by community

  • Incorrect rejection of messages during MAVLink forwarding
  • All bug-fixes made available in the upstream PX4 v1.12 release
Last modified 8mo ago