v0.4.0 - Multi-Airframe Support and 3-Axis Control System

[BryanSouza91]

Multi-Airframe Support and 3-Axis Control System

Summary

This update transitions WingFC from a fixed elevon controller to a modular, multi-airframe flight control system. It introduces a dedicated mixing layer, expands hardware output support to 5 servos, and upgrades the stabilization engine to full 3-axis control (Pitch, Roll, and Yaw).

Major Changes

1. Modular Airframe Mixer

• Created mixer.go to decouple PID control outputs from physical servo movements.
• Added support for several airframe types including Elevons, T-Tail (Single/Dual Aileron), and V-Tail (Single/Dual Aileron).
• Aircraft type is now selectable via a single constant in config.go.

2. 3-Axis Stabilization

• Yaw Control: Added a third PID controller for Yaw/Rudder stabilization.
• Kalman Upgrade: Upgraded the Kalman Filter from 2x2 to 3x3 matrices in kalman.go to track Pitch, Roll, and Yaw states simultaneously.
• Matrix Math: Expanded the internal matrix library to support the higher-dimension calculations required for 3-axis fusion.

3. Hardware and PWM Improvements

• Expanded Outputs: Increased supported servo channels from 2 to 5.
• Frequency Separation: Configured the Seeed XIAO nRF52840 to use separate PWM instances. Servos can run at 50Hz (compatible with analog servos) while the ESC runs at 400Hz for faster throttle response.
• Servo Calibration: Added per-servo min/max limits, subtrim offsets, and signal reversal settings in config.go.

Modified Files

• config.go: Added aircraft types, servo reversals, and yaw PID constants.
• main.go: Integrated new 3-axis control and mixer logic.
• hardware.go: Updated pin mappings and PWM peripheral configurations.
• helpers.go: Implemented setAllServos() and applyReversal() functions.
• kalman.go: Refactored for 3-axis state estimation.
• mixer.go: (New) Core mixing logic for different aircraft configurations.
• matrix.go: Added support for 3x3 and 3x2 matrix operations.
• dshot.go: Added support for DShot ESCs.