PX4-Autopilot/docs/en/releases/main.md

PX4-Autopilot Main Release Notes

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This page is on a release branch, and hence probably out of date. See the latest version.

This contains changes to PX4 main branch since the last major release (PX v1.16).

::: warning PX4 v1.17 is in alpha/beta testing. Update these notes with features that are going to be in main (PX4 v1.18 or later) but not the PX4 v1.17 release. :::

Read Before Upgrading

• Log rotation is now enabled by default. Previously, a single log file grew for the entire flight and old logs were only deleted at boot once free space fell below a fixed 300 MB floor. The logger now caps each log file at SDLOG_MAX_SIZE (new parameter, default 1024 MB) and keeps a configurable percentage of the disk free via SDLOG_ROTATE (new parameter, default 90, so at least 10% free). Cleanup runs at log start rather than boot, so logs can still be downloaded via FTP before they are deleted. See Log Cleanup for details.
• SDLOG_DIRS_MAX behaviour changed: it is now an orthogonal directory-count cap that runs on top of the new space-based cleanup, and the default is 0 (disabled). Previously it enforced a fixed ~300 MB free-space floor even when set to 0. If you relied on that implicit floor, set SDLOG_ROTATE instead.

Please continue reading for upgrade instructions.

Major Changes

• TBD

Upgrade Guide

Other changes

Hardware Support

• TBD

Common

• Remote ID (Open Drone ID) in-flight failsafe: extended COM_ARM_ODID to also trigger a configurable failsafe action (Return, Land, or Terminate) if the Remote ID heartbeat is lost while airborne. Users previously on COM_ARM_ODID=2 retain the same arming behaviour; set to 3 or higher to enable the in-flight action. (PX4-Autopilot#27029)
• QGroundControl Bootloader Update via the SYS_BL_UPDATE parameter has been re-enabled after being broken for a number of releases. (PX4-Autopilot#25032: build: romf: fix generation of rc.board_bootloader_upgrade).
• Feature: Allow prioritization of manual control inputs based on their instance number in ascending or descending order. (PX4-Autopilot#25602: Ascending and descending manual control input priorities).

Control

• Added new flight mode(s): Altitude Cruise (MC), Altitude Cruise (FW). For fixed-wing the mode behaves the same as Altitude mode but you can disable the manual control loss failsafe. (PX4-Autopilot#25435: Add new flight mode: Altitude Cruise).

Safety

• Rotary-wing vehicles now support uncommanded altitude loss detection: if the vehicle descends more than FD_ALT_LOSS meters below its setpoint in altitude-controlled flight, flight termination (and parachute deployment) is triggered. See Altitude Loss Trigger. (PX4-Autopilot#26837)
• GNSS check failsafe: new failsafe that monitors the number of usable GNSS receivers with a 3D fix and their position consistency. The required number of receivers is set via SYS_HAS_NUM_GNSS and the failsafe action via COM_GNSSLOSS_ACT. (PX4-Autopilot#26863)

Estimation

• Added EKF2_POS_LOCK to force constant position fusion while landed, useful for vehicles relying on dead-reckoning sensors (airspeed, optical flow) that provide no aiding on the ground.

Sensors

• Add sbgECom INS driver (PX4-Autopilot#24137)
• Quick magnetometer calibration now supports specifying an arbitrary initial heading (PX4-Autopilot#24637)

Simulation

• SIH: Add option to set wind velocity (PX4-Autopilot#26467)

Debug & Logging

• Asset Tracking: Automatic tracking and logging of external device information including vendor name, firmware and hardware version, serial numbers. Currently supports DroneCAN devices. (PX4-Autopilot#25617)
• Logger: support for small flash storage (e.g. 128 MB W25N NAND on kakuteh7mini, kakuteh7v2, airbrainh743). Logs can now be written directly to an internal littlefs volume instead of requiring an SD card.
• Logger: reworked log rotation and cleanup. Log rotation is now on by default, and cleanup runs at log start rather than boot so logs can be downloaded via FTP before being deleted.
  • New SDLOG_MAX_SIZE (default 1024 MB) caps the size of a single log file; once reached, the logger closes the current file and starts a new one.
  • New SDLOG_ROTATE (default 90) sets the maximum disk usage percentage. Cleanup guarantees (100 - SDLOG_ROTATE)% of the disk stays free at all times, even while writing a new log file. Set 0 to disable space-based cleanup, 100 to allow filling the disk completely.
  • SDLOG_DIRS_MAX is now an orthogonal cap on the number of log directories (default 0 = disabled), on top of the space-based cleanup driven by SDLOG_ROTATE and SDLOG_MAX_SIZE. SITL defaults to 7.
• New mklittlefs systemcmd for reformatting a littlefs volume from the NSH console, analogous to mkfatfs for FAT filesystems.

Ethernet

• TBD

uXRCE-DDS / Zenoh / ROS2

• TBD

MAVLink

• Removed support for deprecated request commands MAV_CMD_REQUEST_AUTOPILOT_CAPABILITIES, MAV_CMD_REQUEST_PROTOCOL_VERSION, MAV_CMD_GET_HOME_POSITION, MAV_CMD_REQUEST_FLIGHT_INFORMATION, MAV_CMD_REQUEST_STORAGE_INFORMATION (Replaced by MAV_CMD_REQUEST_MESSAGE). (PX4-Autopilot#27251: fix(mavlink): Remove deprecated MAV_CMD_REQUEST_AUTOPILOT_CAPABILITIES, PX4-Autopilot#27252: fix(mavlink): Remove legacy mavlink message requestors#27252)

RC

• Parse ELRS Status and Link Statistics TX messages in the CRSF parser.

Multi-Rotor

• Removed parameters MPC_{XY/Z/YAW}_MAN_EXPO and use default value instead, as they were not deemed necessary anymore. (PX4-Autopilot#25435: Add new flight mode: Altitude Cruise).
• Renamed MPC_HOLD_DZ to MAN_DEADZONE to have it globally available in modes that allow for a dead zone. (PX4-Autopilot#25435: Add new flight mode: Altitude Cruise).

VTOL

• TBD

Fixed-wing

• TBD

Rover

• TBD

ROS 2

• TBD