ardupilot/libraries/AP_GPS/AP_GPS_ERB.h

156 lines
5.1 KiB
C++

/*
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/>.
*/
//
// Emlid Reach Binary (ERB) GPS driver for ArduPilot.
// ERB protocol: http://files.emlid.com/ERB.pdf
#pragma once
#include <AP_HAL/AP_HAL.h>
#include "AP_GPS.h"
#include "GPS_Backend.h"
class AP_GPS_ERB : public AP_GPS_Backend
{
public:
using AP_GPS_Backend::AP_GPS_Backend;
// Methods
bool read() override;
AP_GPS::GPS_Status highest_supported_status(void) override { return AP_GPS::GPS_OK_FIX_3D_RTK_FIXED; }
bool supports_mavlink_gps_rtk_message() const override { return true; }
static bool _detect(struct ERB_detect_state &state, uint8_t data);
const char *name() const override { return "ERB"; }
private:
struct PACKED erb_header {
uint8_t preamble1;
uint8_t preamble2;
uint8_t msg_id;
uint16_t length;
};
struct PACKED erb_ver {
uint32_t time; ///< GPS time of week of the navigation epoch [ms]
uint8_t ver_high;
uint8_t ver_medium;
uint8_t ver_low;
};
struct PACKED erb_pos {
uint32_t time; ///< GPS time of week of the navigation epoch [ms]
double longitude;
double latitude;
double altitude_ellipsoid; ///< Height above ellipsoid [m]
double altitude_msl; ///< Height above mean sea level [m]
uint32_t horizontal_accuracy; ///< Horizontal accuracy estimate [mm]
uint32_t vertical_accuracy; ///< Vertical accuracy estimate [mm]
};
struct PACKED erb_stat {
uint32_t time; ///< GPS time of week of the navigation epoch [ms]
uint16_t week;
uint8_t fix_type; ///< see erb_fix_type enum
uint8_t fix_status;
uint8_t satellites;
};
struct PACKED erb_dops {
uint32_t time; ///< GPS time of week of the navigation epoch [ms]
uint16_t gDOP; ///< Geometric DOP
uint16_t pDOP; ///< Position DOP
uint16_t vDOP; ///< Vertical DOP
uint16_t hDOP; ///< Horizontal DOP
};
struct PACKED erb_vel {
uint32_t time; ///< GPS time of week of the navigation epoch [ms]
int32_t vel_north; ///< North velocity component [cm/s]
int32_t vel_east; ///< East velocity component [cm/s]
int32_t vel_down; ///< Down velocity component [cm/s]
uint32_t speed_2d; ///< Ground speed (2-D) [cm/s]
int32_t heading_2d; ///< Heading of motion 2-D [1e5 deg]
uint32_t speed_accuracy; ///< Speed accuracy Estimate [cm/s]
};
struct PACKED erb_rtk {
uint8_t base_num_sats; ///< Current number of satellites used for RTK calculation
uint16_t age_cs; ///< Age of the corrections in centiseconds (0 when no corrections, 0xFFFF indicates overflow)
int32_t baseline_N_mm; ///< distance between base and rover along the north axis in millimeters
int32_t baseline_E_mm; ///< distance between base and rover along the east axis in millimeters
int32_t baseline_D_mm; ///< distance between base and rover along the down axis in millimeters
uint16_t ar_ratio; ///< AR ratio multiplied by 10
uint16_t base_week_number; ///< GPS Week Number of last baseline
uint32_t base_time_week_ms; ///< GPS Time of Week of last baseline in milliseconds
};
// Receive buffer
union PACKED {
DEFINE_BYTE_ARRAY_METHODS
erb_ver ver;
erb_pos pos;
erb_stat stat;
erb_dops dops;
erb_vel vel;
erb_rtk rtk;
} _buffer;
enum erb_protocol_bytes {
PREAMBLE1 = 0x45,
PREAMBLE2 = 0x52,
MSG_VER = 0x01,
MSG_POS = 0x02,
MSG_STAT = 0x03,
MSG_DOPS = 0x04,
MSG_VEL = 0x05,
MSG_RTK = 0x07,
};
enum erb_fix_type {
FIX_NONE = 0x00,
FIX_SINGLE = 0x01,
FIX_FLOAT = 0x02,
FIX_FIX = 0x03,
};
// Packet checksum accumulators
uint8_t _ck_a;
uint8_t _ck_b;
// State machine state
uint8_t _step;
uint8_t _msg_id;
uint16_t _payload_length;
uint16_t _payload_counter;
// 8 bit count of fix messages processed, used for periodic processing
uint8_t _fix_count;
uint32_t _last_pos_time;
uint32_t _last_vel_time;
// do we have new position information?
bool _new_position:1;
// do we have new speed information?
bool _new_speed:1;
// Buffer parse & GPS state update
bool _parse_gps();
// used to update fix between status and position packets
AP_GPS::GPS_Status next_fix = AP_GPS::NO_FIX;
};