// ============================================================
//  Ltm - encoder Lightweight Telemetry (LTM v2)
//  Layout fedele a iNavFlight/inav  src/main/telemetry/ltm.c
//
//  Frame: '$' 'T' <code> <payload...> <crc>
//    code = 'G' | 'A' | 'S' | ...
//    crc  = XOR dei soli byte di payload (dopo il code), little-endian.
//  Letto passivamente da mwp (mwptools) e altri GCS.
// ============================================================
#pragma once
#include <Arduino.h>

namespace Ltm {

// G-frame (GPS): lat/lon in deg*1e7, gs in m/s, alt in cm,
// sats = numero satelliti, fix = 1(no) 2(2D) 3(3D).
// out deve essere >= 18 byte. Ritorna i byte scritti.
size_t gframe(uint8_t* out, int32_t lat, int32_t lon,
              uint8_t gs_mps, int32_t alt_cm, uint8_t sats, uint8_t fix);

// A-frame (Attitude): pitch/roll/heading in gradi interi.
// out >= 10 byte.
size_t aframe(uint8_t* out, int16_t pitch, int16_t roll, int16_t heading);

// S-frame (Status): vbat in mV, current/mAh, rssi 0-255,
// airspeed m/s, flightmode 0-19, statemode bit0=armed bit1=failsafe.
// out >= 11 byte.
size_t sframe(uint8_t* out, uint16_t vbat_mv, uint16_t current,
              uint8_t rssi, uint8_t airspeed,
              uint8_t flightmode, uint8_t statemode);

} // namespace Ltm