// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
/*
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 .
*/
//
// u-blox UBX GPS driver for ArduPilot and ArduPilotMega.
// Code by Michael Smith, Jordi Munoz and Jose Julio, DIYDrones.com
//
// UBlox Lea6H protocol: http://www.u-blox.com/images/downloads/Product_Docs/u-blox6_ReceiverDescriptionProtocolSpec_%28GPS.G6-SW-10018%29.pdf
#ifndef __AP_GPS_UBLOX_H__
#define __AP_GPS_UBLOX_H__
#include
#include
#include "GPS.h"
/*
* try to put a UBlox into binary mode. This is in two parts.
*
* First we send a ubx binary message that enables the NAV_SOL message
* at rate 1. Then we send a NMEA message to set the baud rate to our
* desired rate. The reason for doing the NMEA message second is if we
* send it first the second message will be ignored for a baud rate
* change.
* The reason we need the NAV_SOL rate message at all is some uBlox
* modules are configured with all ubx binary messages off, which
* would mean we would never detect it.
*/
#define UBLOX_SET_BINARY "\265\142\006\001\003\000\001\006\001\022\117$PUBX,41,1,0003,0001,38400,0*26\r\n"
class AP_GPS_UBLOX : public GPS
{
public:
AP_GPS_UBLOX() :
GPS(),
_step(0),
_msg_id(0),
_payload_length(0),
_payload_counter(0),
_fix_count(0),
_disable_counter(0),
next_fix(GPS::FIX_NONE),
need_rate_update(false),
rate_update_step(0)
{}
// Methods
virtual void init(AP_HAL::UARTDriver *s, enum GPS_Engine_Setting nav_setting = GPS_ENGINE_NONE);
virtual bool read();
static bool _detect(uint8_t );
static const prog_char _ublox_set_binary[];
static const uint8_t _ublox_set_binary_size;
float get_lag() { return 0.5; } // ublox lag is lower than the default 1second
private:
// u-blox UBX protocol essentials
struct PACKED ubx_header {
uint8_t preamble1;
uint8_t preamble2;
uint8_t msg_class;
uint8_t msg_id;
uint16_t length;
};
struct PACKED ubx_cfg_nav_rate {
uint16_t measure_rate_ms;
uint16_t nav_rate;
uint16_t timeref;
};
struct PACKED ubx_cfg_msg_rate {
uint8_t msg_class;
uint8_t msg_id;
uint8_t rate;
};
struct PACKED ubx_cfg_nav_settings {
uint16_t mask;
uint8_t dynModel;
uint8_t fixMode;
int32_t fixedAlt;
uint32_t fixedAltVar;
int8_t minElev;
uint8_t drLimit;
uint16_t pDop;
uint16_t tDop;
uint16_t pAcc;
uint16_t tAcc;
uint8_t staticHoldThresh;
uint8_t res1;
uint32_t res2;
uint32_t res3;
uint32_t res4;
};
struct PACKED ubx_nav_posllh {
uint32_t time; // GPS msToW
int32_t longitude;
int32_t latitude;
int32_t altitude_ellipsoid;
int32_t altitude_msl;
uint32_t horizontal_accuracy;
uint32_t vertical_accuracy;
};
struct PACKED ubx_nav_status {
uint32_t time; // GPS msToW
uint8_t fix_type;
uint8_t fix_status;
uint8_t differential_status;
uint8_t res;
uint32_t time_to_first_fix;
uint32_t uptime; // milliseconds
};
struct PACKED ubx_nav_solution {
uint32_t time;
int32_t time_nsec;
int16_t week;
uint8_t fix_type;
uint8_t fix_status;
int32_t ecef_x;
int32_t ecef_y;
int32_t ecef_z;
uint32_t position_accuracy_3d;
int32_t ecef_x_velocity;
int32_t ecef_y_velocity;
int32_t ecef_z_velocity;
uint32_t speed_accuracy;
uint16_t position_DOP;
uint8_t res;
uint8_t satellites;
uint32_t res2;
};
struct PACKED ubx_nav_velned {
uint32_t time; // GPS msToW
int32_t ned_north;
int32_t ned_east;
int32_t ned_down;
uint32_t speed_3d;
uint32_t speed_2d;
int32_t heading_2d;
uint32_t speed_accuracy;
uint32_t heading_accuracy;
};
// Receive buffer
union PACKED {
ubx_nav_posllh posllh;
ubx_nav_status status;
ubx_nav_solution solution;
ubx_nav_velned velned;
ubx_cfg_nav_settings nav_settings;
uint8_t bytes[];
} _buffer;
enum ubs_protocol_bytes {
PREAMBLE1 = 0xb5,
PREAMBLE2 = 0x62,
CLASS_NAV = 0x01,
CLASS_ACK = 0x05,
CLASS_CFG = 0x06,
MSG_ACK_NACK = 0x00,
MSG_ACK_ACK = 0x01,
MSG_POSLLH = 0x2,
MSG_STATUS = 0x3,
MSG_SOL = 0x6,
MSG_VELNED = 0x12,
MSG_CFG_PRT = 0x00,
MSG_CFG_RATE = 0x08,
MSG_CFG_SET_RATE = 0x01,
MSG_CFG_NAV_SETTINGS = 0x24
};
enum ubs_nav_fix_type {
FIX_NONE = 0,
FIX_DEAD_RECKONING = 1,
FIX_2D = 2,
FIX_3D = 3,
FIX_GPS_DEAD_RECKONING = 4,
FIX_TIME = 5
};
enum ubx_nav_status_bits {
NAV_STATUS_FIX_VALID = 1
};
// 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;
uint8_t _class;
// do we have new position information?
bool _new_position;
// do we have new speed information?
bool _new_speed;
uint8_t _disable_counter;
// Buffer parse & GPS state update
bool _parse_gps();
// used to update fix between status and position packets
Fix_Status next_fix;
bool need_rate_update;
uint8_t rate_update_step;
uint32_t _last_fix_time;
void _configure_navigation_rate(uint16_t rate_ms);
void _configure_message_rate(uint8_t msg_class, uint8_t msg_id, uint8_t rate);
void _configure_gps(void);
void _update_checksum(uint8_t *data, uint8_t len, uint8_t &ck_a, uint8_t &ck_b);
void _send_message(uint8_t msg_class, uint8_t msg_id, void *msg, uint8_t size);
void send_next_rate_update(void);
};
#endif // __AP_GPS_UBLOX_H__