2 Commits

Author SHA1 Message Date
844504e92e refactor: ESC abstraction layer with pluggable backends (Issue #388)
BREAKING CHANGE: Hoverboard implementation moved to pluggable vtable architecture.

## Implementation

### New Files
- include/esc_backend.h: Abstract interface (vtable) with:
  - esc_telemetry_t struct (voltage, current, temp, speed, steer, fault)
  - esc_backend_t vtable (init, send, estop, resume, get_telemetry)
  - Runtime registration (esc_backend_register/get)
  - Convenience wrappers (esc_init, esc_send, esc_estop, etc)

- src/esc_backend.c: Backend registry and wrapper implementations

- src/esc_hoverboard.c: Hoverboard backend implementing vtable
  - USART2 @ 115200 baud configuration
  - EFeru FOC packet encoding (0xABCD start, XOR checksum)
  - Backward-compatible hoverboard_init/send wrappers
  - Telemetry stub (future: add RX feedback parsing)

- src/esc_vesc.c: VESC backend stub (filled by Issue #383)
  - Placeholder functions for FSESC 4.20 Plus integration
  - Public vesc_backend_register_impl() for runtime registration
  - Ready for pyvesc protocol implementation

### Modified Files
- src/motor_driver.c: Changed from direct hoverboard_send() calls to esc_send()
  - No logic changes, ESC-agnostic via vtable

- include/config.h: Added ESC_BACKEND define
  - Compile-time selection (default: HOVERBOARD)
  - Comments document architecture for future VESC support

### Removed Files
- src/hoverboard.c: Original implementation merged into esc_hoverboard.c

## Architecture Benefits
1. **Backend Pluggability**: Support multiple ESC types without code duplication
2. **Zero Direct Dependencies**: motor_driver.c never calls hoverboard functions directly
3. **Clean Testing**: Each backend can be tested/stubbed independently
4. **Future-Ready**: VESC integration (Issue #383) just implements the vtable
5. **Backward Compatible**: Existing code calling hoverboard_init/send still works

## Testing
- pio run:  PASS (55.4KB Flash, 16.9KB RAM)
- Hoverboard backend tested via existing balance tests (unchanged logic)
- VESC backend stub compiles and links (no-op until #383 fills implementation)

## Blocks
- Issue #383 (VESC integration) — ready to implement vtable functions
- Issue #384 (pan/tilt servo) — may use independent PWM (not blocked)

## Dependencies
- None — this is pure refactoring, no API changes for callers

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>
2026-03-04 10:36:35 -05:00
80a41e5008 feat: motor driver layer — differential drive, steer ramp, estop
Adds motor_driver.c/h between the balance PID and the raw
hoverboard UART driver:

- Differential drive: balance_cmd → speed, steer_cmd → steer
- Steer-only ramping at MOTOR_STEER_RAMP_RATE (balance PID keeps
  full immediate authority — no ramp on speed channel)
- Headroom clamp: reduces steer so |speed|+|steer|<=MOTOR_CMD_MAX
  ensuring ESC never clips the balance command
- Emergency stop: latches on TILT_FAULT, clears on BALANCE_DISARMED;
  send path stays in 50Hz ESC tick to avoid flooding UART

main.c: replace bare hoverboard_send() with motor_driver_update();
config.h: MOTOR_CMD_MAX=1000, MOTOR_STEER_RAMP_RATE=20 counts/ms

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-02-28 17:15:40 -05:00