Feature overview — Pixhawk 248 firmware Purpose Provide a concise feature list and description for firmware targeting the Pixhawk 248 flight controller (STM32F4-based autopilot) to guide development, testing, or selection. Core flight features

Stabilization controllers: Roll, pitch, yaw PID loops with configurable rate/attitude modes. Flight modes: Stabilize, AltHold, Loiter, RTL (Return-to-Launch), Acro/Manual, Auto (mission), Drift/Brake. Multi-vehicle support: Quad/X/Y6/Hex/Oct configurations and custom mixer mapping. Sensor fusion / EKF: IMU+mag+baro+GPS fusion with state-estimation (EKF2/UKF-capable). Failsafe behaviors: Low-battery, RC loss, GPS loss, sensor failure—configurable actions (RTL, Land, Hold, Shutdown). Battery monitoring: Voltage/current scaling, low/high alarms, SOC estimation. GPS navigation: Waypoint missions, geofencing, guided modes, speed/altitude constraints. Kalman/compass calibration: Onboard auto and manual calibration routines for accel/gyro/compass. Logging: High-rate onboard telemetry and blackbox logging to SD (configurable sample rates). Telemetry links: MAVLink v1/v2 support, configurable serial/mavros ports, telemetry failover.

Safety & robustness

Watchdog/reset handling: HW watchdog and safe boot on critical fault. Redundancy support: Dual IMU/mag and sensor voting/failover logic. Thermal and vibration filtering: Digital filters, notch filters, and vibration logging support. Preflight checks: Sensor, RC, GPS, battery, and parameters checks with configurable arming requirements.

Performance & tuning

Real-time scheduling: Deterministic task scheduling, fixed-rate control loops (e.g., 1 kHz inner loop). Low-latency I/O: DMA-driven sensors, async serial handling, optimized SPI/I2C drivers. Tuning tools: Onboard autotune for PID, logging-assisted tune analysis.

Peripherals & I/O

PWM/PPM output: Multiple PWM outputs, support for DShot, OneShot, and servo smoothing. SBUS/DSM support: Multiple RC input protocols (PWM, SBUS, DSM, PPM, Spektrum). CAN bus: UAVCAN support for external ESCs, GPS, odometry, and redundant peripherals. Camera/Gimbal control: PWM or serial gimbal commands, camera trigger, and ROI for FPV. Companion computer interface: High-bandwidth USB/serial bridge, MAVLink passthrough, USB mass storage for logs.

Configuration & tools

Parameter system: Persistent parameter storage with defaults and runtime updates. Ground station integration: MAVLink-compatible QGroundControl/Mission Planner support. Firmware update: DFU/bootloader support, secure firmware verification, OTA via companion. Modular drivers: Pluggable sensor drivers and easy BSP for new board variants.

Security & integrity

Bootloader verification: Signature/CRC checks on firmware image. Access control: MAVLink command authorization levels and configurable arming locks.