GDL90_Message_Structs.h

/*
     Copyright (C) 2021    Kraus Hamdani Aerospace Inc. All rights reserved.

     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation, either version 3 of the License, or
     (at your option) any later version.

     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.    See the
     GNU General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with this program.    If not, see <http://www.gnu.org/licenses/>.


    Author: GDL90/UCP protocol by uAvionix, 2021.
    Implemented by: Tom Pittenger
 */

#include <stddef.h>
#include <stdbool.h>
#include <stdint.h>

typedef enum __attribute__((__packed__))
{
    GDL90_ID_HEARTBEAT                  = 0,
    GDL90_ID_OWNSHIP_REPORT             = 10,         // 0x0A
    GDL90_ID_OWNSHIP_GEOMETRIC_ALTITUDE = 11,         // 0x0B
    GDL90_ID_IDENTIFICATION             = 37,         // 0x25
    GDL90_ID_SENSOR_MESSAGE             = 40,         // 0x28
    GDL90_ID_TRANSPONDER_CONFIG         = 43,         // 0x2B
    GDL90_ID_MESSAGE_REQUEST            = 44,         // 0x2C
    GDL90_ID_TRANSPONDER_CONTROL        = 45,         // 0x2D
    GDL90_ID_GPS_DATA                   = 46,         // 0x2E
    GDL90_ID_TRANSPONDER_STATUS         = 47,         // 0x2F
} GDL90_MESSAGE_ID;

typedef enum    __attribute__((__packed__))
{
    ADSB_NIC_BARO_UNVERIFIED = 0, // Baro is Gilman bases, and not cross checked
    ADSB_NIC_BARO_VERIFIED = 1, // Baro is cross-checked, or not Gilman based
} ADSB_NIC_BARO; // Barometric Altitude Integrity Code

typedef enum __attribute__((__packed__))
{
    ADSB_AIRBORNE_SUBSONIC     = 0,
    ADSB_AIRBORNE_SUPERSONIC = 1,
    ADSB_ON_GROUND                     = 2,
    // 3 Reserved
} ADSB_AIR_GROUND_STATE; // Determines how horizontal velocity fields are processed in UAT

typedef enum    __attribute__((__packed__))
{
    ADSB_EMERGENCY_NONE             = 0,
    ADSB_EMERGENCY_GENERAL          = 1,
    ADSB_EMERGENCY_MEDICAL          = 2,
    ADSB_EMERGENCY_MINIMUM_FUEL     = 3,
    ADSB_EMERGENCY_NO_COMMUNICATION = 4,
    ADSB_EMERGNECY_INTERFERENCE     = 5,
    ADSB_EMERGENCY_DOWNED_AIRCRAFT  = 6,
    ADSB_EMERGENCY_UAS_LOST_LINK    = 7,
    // 7 Reserved
} ADSB_EMERGENCY_STATUS;

#define GDL90_TRANSPONDER_CONTROL_VERSION (2)
#if GDL90_TRANSPONDER_CONTROL_VERSION == 1
typedef struct __attribute__((__packed__))
{
    GDL90_MESSAGE_ID       messageId;
    uint8_t                version;
    ADSB_NIC_BARO          baroCrossChecked         : 1;
    ADSB_AIR_GROUND_STATE  airGroundState           : 2;
    uint8_t                identActive              : 1;
    uint8_t                modeAEnabled             : 1;
    uint8_t                modeCEnabled             : 1;
    uint8_t                modeSEnabled             : 1;
    uint8_t                es1090TxEnabled          : 1;
    int32_t                externalBaroAltitude_mm;
    uint16_t               squawkCode;
    ADSB_EMERGENCY_STATUS  emergencyState;
    uint8_t                callsign[8];
} GDL90_TRANSPONDER_CONTROL_MSG;
#elif GDL90_TRANSPONDER_CONTROL_VERSION == 2
typedef struct __attribute__((__packed__))
{
    GDL90_MESSAGE_ID       messageId;
    uint8_t                version;
    ADSB_NIC_BARO          baroCrossChecked  : 1;
    ADSB_AIR_GROUND_STATE  airGroundState    : 2;
    uint8_t                identActive       : 1;
    uint8_t                modeAEnabled      : 1;
    uint8_t                modeCEnabled      : 1;
    uint8_t                modeSEnabled      : 1;
    uint8_t                es1090TxEnabled   : 1;
    int32_t                externalBaroAltitude_mm;
    uint16_t               squawkCode;
    ADSB_EMERGENCY_STATUS  emergencyState;
    uint8_t                callsign[8];
    uint8_t                rfu               : 7;
    uint8_t                x_bit             : 1;
} GDL90_TRANSPONDER_CONTROL_MSG;
#endif

#define GDL90_STATUS_MAX_ALTITUDE_FT (101338)
#define GDL90_STATUS_MIN_ALTITUDE_FT (-1000)
typedef struct __attribute__((__packed__))
{
    GDL90_MESSAGE_ID       messageId;
    uint8_t                version;
    uint8_t                rfu                      : 2;
    uint8_t                x_bit                    : 1;
    uint8_t                identActive              : 1;
    uint8_t                modeAEnabled             : 1;
    uint8_t                modeCEnabled             : 1;
    uint8_t                modeSEnabled             : 1;
    uint8_t                es1090TxEnabled          : 1;
    uint16_t               modeARepliesPerSecond;
    uint16_t               modecRepliesPerSecond;
    uint16_t               modeSRepliesPerSecond;
    uint16_t               squawkCode;
    uint16_t               crc;
} GDL90_TRANSPONDER_STATUS_MSG;

typedef struct __attribute__((__packed__))
{
    GDL90_MESSAGE_ID  messageId;
    uint8_t           version;
    uint8_t           indicatingOnGround     : 1;
    uint8_t           interrogatedSinceLast  : 1;
    uint8_t           fault                  : 1;
    uint8_t           identActive            : 1;
    uint8_t           modeAEnabled           : 1;
    uint8_t           modeCEnabled           : 1;
    uint8_t           modeSEnabled           : 1;
    uint8_t           es1090TxEnabled        : 1;
    uint8_t           latitude[3];
    uint8_t           longitude[3];
    uint32_t          track_Heading          : 8;
    uint32_t          horizontalVelocity     :12;
    uint32_t          altitude               :12;
    uint16_t          squawkCode;
    uint8_t           NIC                    : 4;
    uint8_t           NACp                   : 4;
    uint8_t           temperature;
    uint16_t          crc;
} GDL90_TRANSPONDER_STATUS_MSG_V3;


typedef struct __attribute__((__packed__))
{
    uint8_t HPLfdeActive  : 1;
    uint8_t fault         : 1;
    uint8_t HrdMagNorth   : 1;
    uint8_t reserved      : 5;
} GDL90_GPS_NAV_STATE;

typedef enum __attribute__((__packed__))
{
    GPS_FIX_NONE = 0,
    GPS_FIX_NO_FIX = 1,
    GPS_FIX_2D = 2,
    GPS_FIX_3D = 3,
    GPS_FIX_DIFFERENTIAL = 4,
    GPS_FIX_RTK = 5,
} GPS_FIX;

typedef struct __attribute__((__packed__))
{
    GDL90_MESSAGE_ID    messageId;
    uint8_t             version;
    uint32_t            utcTime_s;    // Time since GPS epoch
    int32_t             latitude_ddE7;
    int32_t             longitude_ddE7;
    int32_t             altitudeGnss_mm; // Height about WGS84 ellipsoid
    // Protection Limits. FD or SBAS-based depending on state bits
    uint32_t            HPL_mm;
    uint32_t            VPL_cm;
    // FOMS
    uint32_t            horizontalFOM_mm;
    uint16_t            verticalFOM_cm;
    uint16_t            horizontalVelocityFOM_mmps;
    uint16_t            verticalVelocityFOM_mmps;
    // Velocities
    int16_t             verticalVelocity_cmps;
    int32_t             northVelocity_mmps; // millimeter/s
    int32_t             eastVelocity_mmps;
    // State
    GPS_FIX             fixType;
    GDL90_GPS_NAV_STATE navState;
    uint8_t             satsUsed;
} GDL90_GPS_DATA_V2;
#define GDL90_GPS_DATA_VERSION    (2)

typedef struct __attribute__((__packed__))
{
    GDL90_MESSAGE_ID    messageId;
    uint8_t             version;
    GDL90_MESSAGE_ID    reqMsgId;
} GDL90_TRANSPONDER_MESSAGE_REQUEST_V2;

typedef enum __attribute__((__packed__))
{
    GDL90_BARO_DATA_SOURCE_INTERNAL = 0,
    GDL90_BARO_DATA_SOURCE_EXTERNAL,
}GDL90_BARO_DATA_SOURCE;

typedef enum    __attribute__((__packed__))
{
    ADSB_SDA_UNKNOWN    = 0,
    ADSB_SDA_10_NEG3    = 1,
    ADSB_SDA_10_NEG5    = 2,
    ADSB_SDA_10_NEG7    = 3,
} ADSB_SDA; // System Design Assurance

typedef enum __attribute__((__packed__))
{
    ADSB_SIL_UNKNOWN    = 0,
    ADSB_SIL_10_NEG3    = 1,
    ADSB_SIL_10_NEG5    = 2,
    ADSB_SIL_10_NEG7    = 3,
} ADSB_SIL; // Source Integrity Level

typedef enum __attribute__((__packed__))
{
    ADSB_AV_LW_NO_DATA     = 0,
    ADSB_AV_LW_15M_23M     = 1,
    ADSB_AV_LW_25M_28P5M   = 2,
    ADSB_AV_LW_25M_34M     = 3,
    ADSB_AV_LW_35M_33M     = 4,
    ADSB_AV_LW_35M_38M     = 5,
    ADSB_AV_LW_45M_39P5M   = 6,
    ADSB_AV_LW_45M_45M     = 7,
    ADSB_AV_LW_55M_45M     = 8,
    ADSB_AV_LW_55M_52M     = 9,
    ADSB_AV_LW_65M_59P5M   = 10,
    ADSB_AV_LW_65M_67M     = 11,
    ADSB_AV_LW_75M_72P5M   = 12,
    ADSB_AV_LW_75M_80M     = 13,
    ADSB_AV_LW_85M_80M     = 14,
    ADSB_AV_LW_85M_90M     = 15,
} ADSB_AIRCRAFT_LENGTH_WIDTH;

typedef enum __attribute__((__packed__))
{
    ADSB_NOT_UAT_IN_CAPABLE   = 0,
    ADSB_UAT_IN_CAPABLE       = 1
} ADSB_UAT_IN_CAPABILITY;

typedef enum __attribute__((__packed__))
{
    ADSB_NOT_1090ES_IN_CAPABLE = 0,
    ADSB_1090ES_IN_CAPABLE     = 1
} ADSB_1090ES_IN_CAPABILITY;

typedef enum __attribute__((__packed__))
{
    ADSB_GPS_LON_NO_DATA = 0,
    ADSB_GPS_LON_FROM_SENSOR = 1,
    // 2 - 31 valid values in 2 meter increments
} ADSB_GPS_LONGITUDINAL_OFFSET;

typedef enum __attribute__((__packed__))
{
    ADSB_GPS_LAT_NO_DATA = 0,
    ADSB_GPS_LAT_LEFT_2M = 1,
    ADSB_GPS_LAT_LEFT_4M = 2,
    ADSB_GPS_LAT_LEFT_6M = 3,
    ADSB_GPS_LAT_0M = 4,
    ADSB_GPS_LAT_RIGHT_2M = 5,
    ADSB_GPS_LAT_RIGHT_4M = 6,
    ADSB_GPS_LAT_RIGHT_6M = 7,
} ADSB_GPS_LATERAL_OFFSET;

typedef enum __attribute__((__packed__))
{
    ADSB_EMITTER_NO_INFO           = 0,
    ADSB_EMITTER_LIGHT             = 1,
    ADSB_EMITTER_SMALL             = 2,
    ADSB_EMITTER_LARGE             = 3,
    ADSB_EMITTER_HIGH_VORTEX_LARGE = 4,
    ADSB_EMITTER_HEAVY             = 5,
    ADSB_EMITTER_HIGHLY_MANUV      = 6,
    ADSB_EMITTER_ROTOCRAFT         = 7,
    // 8 Unassigned
    ADSB_EMITTER_GLIDER            = 9,
    ADSB_EMITTER_LIGHTER_AIR       = 10,
    ADSB_EMITTER_PARACHUTE         = 11,
    ADSB_EMITTER_ULTRA_LIGHT       = 12,
    // 13 Unassigned
    ADSB_EMITTER_UAV               = 14,
    ADSB_EMITTER_SPACE             = 15,
    // 16 Unassigned

    // Surface types
    ADSB_EMITTER_EMERGENCY_SURFACE = 17,
    ADSB_EMITTER_SERVICE_SURFACE   = 18,

    // Obstacle types
    ADSB_EMITTER_POINT_OBSTACLE    = 19,
    ADSB_EMITTER_CLUSTER_OBSTACLE  = 20,
    ADSB_EMITTER_LINE_OBSTACLE     = 21,
    // 22 - 39 Reserved
} ADSB_EMITTER; // ADSB Emitter Category

typedef enum __attribute__((__packed__))
{
    PING_COM_1200_BAUD      = 0,
    PING_COM_2400_BAUD      = 1,
    PING_COM_4800_BAUD      = 2,
    PING_COM_9600_BAUD      = 3,
    PING_COM_19200_BAUD     = 4,
    PING_COM_38400_BAUD     = 5,
    PING_COM_57600_BAUD     = 6,
    PING_COM_115200_BAUD    = 7,
    PING_COM_921600_BAUD    = 8,
} PING_COM_RATE;

typedef enum __attribute__((__packed__))
{
    CONFIG_VALIDITY_ICAO                  = 1 << 0,
    CONFIG_VALIDITY_SIL                   = 1 << 1,
    CONFIG_VALIDITY_SDA                   = 1 << 2,
    CONFIG_VALIDITY_BARO_ALT_SOURCE       = 1 << 3,
    CONFIG_VALIDITY_AIRCRAFT_MAX_SPEED    = 1 << 4,
    CONFIG_VALIDITY_TEST_MODE             = 1 << 5,
    CONFIG_VALIDITY_ADSB_IN_CAP           = 1 << 6,
    CONFIG_VALIDITY_AIRCRAFT_LEN_WIDTH    = 1 << 7,
    CONFIG_VALIDITY_ANT_LAT_OFFSET        = 1 << 8,
    CONFIG_VALIDITY_ANT_LONG_OFFSET       = 1 << 9,
    CONFIG_VALIDITY_AIRCRAFT_REG          = 1 << 10,
    CONFIG_VALIDITY_AIRCRAFT_STALL_SPEED  = 1 << 11,
    CONFIG_VALIDITY_AIRCRAFT_EMITTER_TYPE = 1 << 12,
    CONFIG_VALIDITY_DEF_1090ES_TX_MODE    = 1 << 13,
    CONFIG_VALIDITY_DEF_MODES_REPLY_MODE  = 1 << 14,
    CONFIG_VALIDITY_DEF_MODEC_REPLY_MODE  = 1 << 15,
    CONFIG_VALIDITY_DEF_MODEA_REPLY_MODE  = 1 << 16,
    CONFIG_VALIDITY_SERIAL_BAUD_RATE      = 1 << 17,
    CONFIG_VALIDITY_DEF_MODEA_SQUAWK      = 1 << 18,
    CONFIG_VALIDITY_BARO_100              = 1 << 19,
    CONFIG_VALIDITY_IN_PROTOCOL           = 1 << 20,
    CONFIG_VALIDITY_OUT_PROTOCOL          = 1 << 21,
} CONFIG_VALIDITY;

typedef union __attribute__((__packed__))
{
    struct __attribute__((__packed__))
    {
        uint32_t icaoValid : 1;
        uint32_t silValid : 1;
        uint32_t sdaValid : 1;
        uint32_t baroAltSourceValid : 1;
        uint32_t aircraftMaxSpeedValid : 1;
        uint32_t testModeValid : 1;
        uint32_t adsbInCapValid : 1;
        uint32_t aircraftLenWidthValid : 1;
        uint32_t aircraftLatOffsetValid : 1;
        uint32_t aircraftLongOffsetValid : 1;
        uint32_t aircraftRegValid : 1;
        uint32_t aircraftStallSpeedValid : 1;
        uint32_t aircraftEmitterCatValid : 1;
        uint32_t default1090ExTxModeValid : 1;
        uint32_t defaultModeSReplyModeValid : 1;
        uint32_t defaultModeCReplyModeValid : 1;
        uint32_t defaultModeAReplyModeValid : 1;
        uint32_t serialBaudRateValid : 1;
        uint32_t defaultModeASquawkValid : 1;
        uint32_t baro100Valid : 1;
        uint32_t inProtocolValid : 1;
        uint32_t outProtocolValid : 1;
        uint32_t reserved : 10;
    };
    CONFIG_VALIDITY raw;
} CONFIG_VALIDITY_BITMASK;

typedef enum __attribute__((__packed__))
{
    PING_PROTOCOL_NONE     = 0,
    PING_PROTOCOL_MAVLINK  = 1 << 0,
    PING_PROTOCOL_UCP      = 1 << 1,
    PING_PROTOCOL_APOLLO   = 1 << 9,
    PING_PROTOCOL_UCP_HD   = 1 << 10,
} PING_PROTOCOL;

typedef union
{
    struct __attribute__((__packed__))
    {
        uint16_t mavlink : 1;
        uint16_t ucp : 1;
        uint16_t reserved1 : 7;
        uint16_t apollo : 1;
        uint16_t ucphd : 1;
        uint16_t reserved2 : 5;
    };
    PING_PROTOCOL raw;
} PING_PROTOCOL_MASK;

typedef struct __attribute__((__packed__))
{
    GDL90_MESSAGE_ID             messageId;
    uint8_t                      version;
    uint8_t                      icaoAddress[3];
    uint8_t                      maxSpeed            : 3;
    GDL90_BARO_DATA_SOURCE       baroAltSource       : 1;
    ADSB_SDA                     SDA                 : 2;
    ADSB_SIL                     SIL                 : 2;
    ADSB_AIRCRAFT_LENGTH_WIDTH   lengthWidth         : 4;
    ADSB_1090ES_IN_CAPABILITY    es1090InCapable     : 1;
    ADSB_UAT_IN_CAPABILITY       uatInCapable        : 1;
    uint8_t                      testMode            : 2;
    ADSB_GPS_LONGITUDINAL_OFFSET longitudinalOffset  : 5;
    ADSB_GPS_LATERAL_OFFSET      lateralOffset       : 3;
    uint8_t                      registration[8];
    uint16_t                     stallSpeed_cmps;
    ADSB_EMITTER                 emitterType;
    PING_COM_RATE                baudRate            : 4;
    uint8_t                      modeAEnabled        : 1;
    uint8_t                      modeCEnabled        : 1;
    uint8_t                      modeSEnabled        : 1;
    uint8_t                      es1090TxEnabled     : 1;
    uint16_t                     defaultSquawk;
    CONFIG_VALIDITY_BITMASK      valdityBitmask;
    uint8_t                      rfu                 : 7;
    uint8_t                      baro100             : 1;
    PING_PROTOCOL_MASK           inProtocol;
    PING_PROTOCOL_MASK           outProtocol;
    uint16_t                     crc;
} GDL90_TRANSPONDER_CONFIG_MSG_V4_V5;


typedef struct __attribute__((__packed__))
{
    uint8_t                     fwMajorVersion;
    uint8_t                     fwMinorVersion;
    uint8_t                     fwBuildVersion;
    uint8_t                     hwId; // TODO Ugh should be 16 bits
    uint64_t                    serialNumber;
} GDL90_DEVICE_ID;

typedef struct __attribute__((__packed__))
{
    GDL90_MESSAGE_ID messageId;
    uint8_t          protocolVersion;
    GDL90_DEVICE_ID  primary;
    GDL90_DEVICE_ID  secondary;
    uint8_t          primaryFWID;
    uint32_t         primaryCRC;
    uint8_t          secondaryFWID;
    uint32_t         secondaryCRC;
    uint8_t          primaryFwPartNumber[15];
    uint8_t          secondaryFwPartNumber[15];
    uint16_t         crc;
} GDL90_IDENTIFICATION_V3;
#define GDL90_IDENT_PROTOCOL_VERSION (3)


typedef struct __attribute__((__packed__))
{
    struct
    {
        uint8_t uatInitialized : 1;

        // GDL90 public spec defines next bit as reserved
        // uAvionix maps extra failure condition
        uint8_t functionFailureGnssDataFrequency : 1;

        uint8_t ratcs : 1;
        uint8_t gpsBatteryLow : 1;
        uint8_t addressType : 1;
        uint8_t ident : 1;
        uint8_t maintenanceRequired : 1;
        uint8_t gpsPositionValid : 1;
    } one;
    struct __attribute__((__packed__))
    {

        uint8_t utcOk : 1;

        // GDL90 public spec defines next four bits as reserved
        // uAvionix maps extra failure conditions
        uint8_t functionFailureGnssUnavailable : 1;
        uint8_t functionFailureGnssNo3dFix : 1;
        uint8_t functionFailureBroadcastMonitor : 1;
        uint8_t functionFailureTransmitSystem : 1;

        uint8_t csaNotAvailable : 1;
        uint8_t csaRequested : 1;
        uint8_t timestampMsb : 1;
    } two;
} GDL90_HEARTBEAT_STATUS;

typedef struct __attribute__((__packed__))
{
    GDL90_MESSAGE_ID             messageId;
    GDL90_HEARTBEAT_STATUS status;
    uint16_t                             timestamp;

    // Need to flip before TX
    union
    {
        struct __attribute__((__packed__))
        {
            uint16_t uatMessages : 10;
            uint16_t rfu : 1;
            uint16_t uplinkMessages : 5;
        };
        uint16_t messageCount;
    };
    uint16_t crc;
} GDL90_HEARTBEAT;

typedef enum __attribute__((__packed__))
{
    GDL90_ADDRESS_ADSB_ICAO,
    GDL90_ADDRESS_ADSB_SELF_ASSIGNED,
    GDL90_ADDRESS_TISB_ICAO,
    GDL90_ADDRESS_TISB_TRACK_ID,
    GDL90_ADDRESS_SURFACE,
    GDL90_ADDRESS_GROUND_BEACON,
} GDL90_ADDRESS_TYPE;

typedef enum __attribute__((__packed__))
{
    GDL90_NO_ALERT,
    GDL90_ALERT,
} GDL90_TRAFFIC_ALERT;

typedef enum __attribute__((__packed__))
{
    GDL90_MISC_INVALID,
    GDL90_MISC_TRUE_TRACK,
    GDL90_MISC_HEADING_MAGNETIC,
    GDL90_MISC_HEADING_TRUE,
} GDL90_MISC_TRACK_TYPE;

typedef enum __attribute__((__packed__))
{
    GDL90_MISC_REPORT_UPDATED,
    GDL90_MISC_REPORT_EXTRAPOLATED,
} GDL90_MISC_REPORT_TYPE;

typedef enum __attribute__((__packed__))
{
    GDL90_MISC_ON_GROUND,
    GDL90_MISC_AIRBORNE,
} GDL90_MISC_AG_STATE;

typedef union
{
    struct __attribute__((__packed__))
    {
        GDL90_MISC_TRACK_TYPE  track : 2;
        GDL90_MISC_REPORT_TYPE reportType : 1;
        GDL90_MISC_AG_STATE    agState : 1;
    };
    uint8_t data;
} GDL90_MISCELLANEOUS;

typedef struct __attribute__((__packed__))
{
    GDL90_ADDRESS_TYPE addressType: 4;
    GDL90_TRAFFIC_ALERT trafficAlert : 4;

    uint8_t address[3];

    uint8_t latitude[3]; // 180 deg / 2^23
    uint8_t longitude[3]; // 180 deg / 2^23

    // Byte order must be flipped before TX
    union
    {
        struct __attribute__((__packed__))
        {
            uint16_t misc : 4;
            uint16_t altitude : 12;
        };
        uint16_t altitudeMisc;
    };

    uint8_t NACp : 4;
    uint8_t NIC : 4;

    // Byte order must be flipped before TX
    union
    {
        struct __attribute__((__packed__))
        {
            uint32_t heading : 8;
            uint32_t verticalVelocity : 12;
            uint32_t horizontalVelocity : 12;
        };
        uint32_t velocities;
    };

    uint8_t emitterCategory;
    uint8_t callsign[8];

    uint8_t rfu : 4;
    uint8_t emergencyCode : 4;
} GDL90_REPORT;

typedef struct __attribute__((__packed__))
{
    GDL90_MESSAGE_ID messageId;
    GDL90_REPORT     report;
    uint16_t         crc;
} GDL90_OWNSHIP_REPORT;
typedef GDL90_OWNSHIP_REPORT GDL90_TRAFFIC_REPORT;

typedef enum __attribute__((__packed__))
{
    GDL90_NO_WARNING,
    GDL90_WARNING,
} GDL90_VERTICAL_WARNING;

typedef struct __attribute__((__packed__))
{
    GDL90_MESSAGE_ID messageId;
    uint16_t geometricAltitude; // 5 ft resolution

    // Must be endian swapped before TX
    union
    {
        struct __attribute__((__packed__))
        {
            uint16_t verticalFOM : 15;
            GDL90_VERTICAL_WARNING verticalWarning : 1;
        };
        uint16_t veritcalMetrics;
    };
    uint16_t crc;
} GDL90_OWNSHIP_GEO_ALTITUDE;

typedef enum __attribute__((__packed__))
{
    GDL90_SENSOR_AHRS = 0,
    GDL90_SENSOR_BARO = 1,
    GDL90_SENSOR_CO = 2,
    GDL90_SENSOR_DEVICE = 3
} GDL90_SENSOR_TYPE;

typedef struct __attribute__((__packed__))
{
    GDL90_MESSAGE_ID  messageId;
    GDL90_SENSOR_TYPE sensorType;
    uint32_t          pressure_mbarE2;
    int32_t           pressureAlt_mm;
    int16_t           temperature_cE2;
    uint16_t          crc;
} GDL90_SENSOR_BARO_MESSAGE;