ardupilot/libraries/AP_RangeFinder/AP_RangeFinder_NMEA.h

87 lines
3.2 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/>.
*/
#pragma once
#include "AP_RangeFinder_config.h"
#if AP_RANGEFINDER_NMEA_ENABLED
#include "AP_RangeFinder.h"
#include "AP_RangeFinder_Backend_Serial.h"
class AP_RangeFinder_NMEA : public AP_RangeFinder_Backend_Serial
{
public:
static AP_RangeFinder_Backend_Serial *create(
RangeFinder::RangeFinder_State &_state,
AP_RangeFinder_Params &_params) {
return NEW_NOTHROW AP_RangeFinder_NMEA(_state, _params);
}
protected:
MAV_DISTANCE_SENSOR _get_mav_distance_sensor_type() const override {
return MAV_DISTANCE_SENSOR_ULTRASOUND;
}
private:
using AP_RangeFinder_Backend_Serial::AP_RangeFinder_Backend_Serial;
/// enum for handled messages
enum sentence_types : uint8_t {
SONAR_UNKNOWN = 0,
SONAR_DBT,
SONAR_DPT,
SONAR_MTW, // mean water temperature
SONAR_HDED, // hondex custom sonar message
};
// get a distance reading
bool get_reading(float &reading_m) override;
// get temperature reading in C. returns true on success and populates temp argument
bool get_temp(float &temp) const override;
uint16_t read_timeout_ms() const override { return 3000; }
// add a single character to the buffer and attempt to decode
// returns true if a distance was successfully decoded
// distance should be pulled directly from _distance_m member
bool decode(char c);
// decode the just-completed term
// returns true if new sentence has just passed checksum test and is validated
bool decode_latest_term();
// message decoding related members
char _term[15]; // buffer for the current term within the current sentence
uint8_t _term_offset; // offset within the _term buffer where the next character should be placed
uint8_t _term_number; // term index within the current sentence
float _distance_m = -1.0f; // distance in meters parsed from a term, -1 if no distance
float _temp_unvalidated; // unvalidated temperature in C (may have failed checksum)
float _temp; // temperature in C (validated)
uint32_t _temp_readtime_ms; // system time we last read a validated temperature, 0 if never read
uint8_t _checksum; // checksum accumulator
bool _term_is_checksum; // current term is the checksum
sentence_types _sentence_type; // the sentence type currently being processed
bool _sentence_done; // true if this sentence has already been decoded
};
#endif // AP_RANGEFINDER_NMEA_ENABLED