nmea.h

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/**
 * @file nmea.h
 *
 * NMEA protocol definitions
 *
 * @author WeiPeng Guo <guoweipeng1990@sina.com>
 * @author Stone White <stone@thone.io>
 * @author Jose Jimenez-Berni <berni@ias.csic.es>
 *
 */

#pragma once

#include "gps_helper.h"
#include "unicore.h"

class RTCMParsing;

#define NMEA_RECV_BUFFER_SIZE 1024
#define NMEA_DEFAULT_BAUDRATE 115200

class GPSDriverNMEA : public GPSHelper
{
public:
	/**
	 * @param heading_offset heading offset in radians [-pi, pi]. It is substracted from the measurement.
	 */
	GPSDriverNMEA(GPSCallbackPtr callback, void *callback_user,
		      sensor_gps_s *gps_position,
		      satellite_info_s *satellite_info,
		      float heading_offset = 0.f);

	virtual ~GPSDriverNMEA();

	int receive(unsigned timeout) override;
	int configure(unsigned &baudrate, const GPSConfig &config) override;

private:
	void handleHeading(float heading_deg, float heading_stddev_deg);
	void request_unicore_messages();

	UnicoreParser _unicore_parser;
	gps_abstime _unicore_heading_received_last;

	enum class NMEADecodeState {
		uninit,
		got_sync1,
		got_asteriks,
		got_first_cs_byte,
		decode_rtcm3
	};

	void decodeInit(void);
	int handleMessage(int len);
	int parseChar(uint8_t b);

	int32_t read_int();
	double read_float();
	char read_char();

	sensor_gps_s *_gps_position {nullptr};
	satellite_info_s *_satellite_info {nullptr};
	double _last_POS_timeUTC{0};
	double _last_VEL_timeUTC{0};
	uint64_t _last_timestamp_time{0};

	uint8_t _sat_num_gga{0};
	uint8_t _sat_num_gns{0};
	uint8_t _sat_num_gsv{0};
	uint8_t _sat_num_gpgsv{0};
	uint8_t _sat_num_glgsv{0};
	uint8_t _sat_num_gagsv{0};
	uint8_t _sat_num_gbgsv{0};
	uint8_t _sat_num_bdgsv{0};

	bool _clock_set {false};

//  check if we got all basic essential packages we need
	bool _TIME_received{false};
	bool _POS_received{false};
	bool _ALT_received{false};
	bool _SVNUM_received{false};
	bool _SVINFO_received{false};
	bool _FIX_received{false};
	bool _DOP_received{false};
	bool _VEL_received{false};
	bool _EPH_received{false};
	bool _HEAD_received{false};

	NMEADecodeState _decode_state{NMEADecodeState::uninit};
	uint8_t _rx_buffer[NMEA_RECV_BUFFER_SIZE] {};
	uint16_t _rx_buffer_bytes{0};

	OutputMode _output_mode{OutputMode::GPS};

	RTCMParsing *_rtcm_parsing{nullptr};

	float _heading_offset;
};