Line data    Source code

       1             : /*
       2             :    This program is free software: you can redistribute it and/or modify
       3             :    it under the terms of the GNU General Public License as published by
       4             :    the Free Software Foundation, either version 3 of the License, or
       5             :    (at your option) any later version.
       6             : 
       7             :    This program is distributed in the hope that it will be useful,
       8             :    but WITHOUT ANY WARRANTY; without even the implied warranty of
       9             :    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      10             :    GNU General Public License for more details.
      11             : 
      12             :    You should have received a copy of the GNU General Public License
      13             :    along with this program.  If not, see <http://www.gnu.org/licenses/>.
      14             :  */
      15             : 
      16             : #pragma once
      17             : 
      18             : #include "AP_RangeFinder_config.h"
      19             : 
      20             : #if AP_RANGEFINDER_NMEA_ENABLED
      21             : 
      22             : #include "AP_RangeFinder.h"
      23             : #include "AP_RangeFinder_Backend_Serial.h"
      24             : 
      25             : class AP_RangeFinder_NMEA : public AP_RangeFinder_Backend_Serial
      26             : {
      27             : 
      28             : public:
      29             : 
      30           3 :     static AP_RangeFinder_Backend_Serial *create(
      31             :         RangeFinder::RangeFinder_State &_state,
      32             :         AP_RangeFinder_Params &_params) {
      33           3 :         return NEW_NOTHROW AP_RangeFinder_NMEA(_state, _params);
      34             :     }
      35             : 
      36             : protected:
      37             : 
      38        2698 :     MAV_DISTANCE_SENSOR _get_mav_distance_sensor_type() const override {
      39        2698 :         return MAV_DISTANCE_SENSOR_ULTRASOUND;
      40             :     }
      41             : 
      42             : private:
      43             : 
      44             :     using AP_RangeFinder_Backend_Serial::AP_RangeFinder_Backend_Serial;
      45             : 
      46             :     /// enum for handled messages
      47             :     enum sentence_types : uint8_t {
      48             :         SONAR_UNKNOWN = 0,
      49             :         SONAR_DBT,
      50             :         SONAR_DPT,
      51             :         SONAR_MTW,  // mean water temperature
      52             :         SONAR_HDED, // hondex custom sonar message
      53             :     };
      54             : 
      55             :     // get a distance reading
      56             :     bool get_reading(float &reading_m) override;
      57             : 
      58             :     // get temperature reading in C.  returns true on success and populates temp argument
      59             :     bool _get_temp(float &temp) const override;
      60             : 
      61       22782 :     uint16_t read_timeout_ms() const override { return 3000; }
      62             : 
      63             :     // add a single character to the buffer and attempt to decode
      64             :     // returns true if a distance was successfully decoded
      65             :     // distance should be pulled directly from _distance_m member
      66             :     bool decode(char c);
      67             : 
      68             :     // decode the just-completed term
      69             :     // returns true if new sentence has just passed checksum test and is validated
      70             :     bool decode_latest_term();
      71             : 
      72             :     // message decoding related members
      73             :     char _term[15];                         // buffer for the current term within the current sentence
      74             :     uint8_t _term_offset;                   // offset within the _term buffer where the next character should be placed
      75             :     uint8_t _term_number;                   // term index within the current sentence
      76             :     float _distance_m = -1.0f;              // distance in meters parsed from a term, -1 if no distance
      77             :     float _temp_unvalidated;                // unvalidated temperature in C (may have failed checksum)
      78             :     float _temp;                            // temperature in C (validated)
      79             :     uint32_t _temp_readtime_ms;             // system time we last read a validated temperature, 0 if never read
      80             :     uint8_t _checksum;                      // checksum accumulator
      81             :     bool _term_is_checksum;                 // current term is the checksum
      82             :     sentence_types _sentence_type;          // the sentence type currently being processed
      83             :     bool _sentence_done;                    // true if this sentence has already been decoded
      84             : };
      85             : 
      86             : #endif  // AP_RANGEFINDER_NMEA_ENABLED