mirror of https://github.com/ArduPilot/ardupilot
74 lines
2.3 KiB
C++
74 lines
2.3 KiB
C++
#pragma once
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#include "AP_Airspeed_config.h"
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#if AP_AIRSPEED_NMEA_ENABLED
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#include "AP_Airspeed_Backend.h"
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#include <AP_HAL/AP_HAL.h>
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class AP_Airspeed_NMEA : public AP_Airspeed_Backend
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{
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public:
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using AP_Airspeed_Backend::AP_Airspeed_Backend;
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// probe and initialise the sensor
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bool init(void) override;
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// this reads airspeed directly
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bool has_airspeed() override {return true;}
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// read the from the sensor
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bool get_airspeed(float &airspeed) override;
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// return the current temperature in degrees C
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bool get_temperature(float &temperature) override;
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private:
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// pointer to serial uart
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AP_HAL::UARTDriver *_uart = nullptr;
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// add a single character to the buffer and attempt to decode
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// returns true if a complete sentence was successfully decoded
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// distance should be pulled directly from _distance_m member
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bool decode(char c);
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// decode the just-completed term
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// returns true if new sentence has just passed checksum test and is validated
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bool decode_latest_term();
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// enum for handled messages
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enum sentence_types : uint8_t {
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TPYE_MTW = 0,
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TYPE_VHW,
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};
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// message decoding related members
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char _term[15]; // buffer for the current term within the current sentence
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uint8_t _term_offset; // offset within the _term buffer where the next character should be placed
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uint8_t _term_number; // term index within the current sentence
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float _speed; // speed in m/s
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float _temp; // temp in deg c
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uint8_t _checksum; // checksum accumulator
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bool _term_is_checksum; // current term is the checksum
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bool _sentence_done; // has the current term already been decoded
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bool _sentence_valid; // is the decodeing valid so far
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sentence_types _sentence_type; // the sentence type currently being processed
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// Store the temp ready for a temp request
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float _temp_sum;
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uint16_t _temp_count;
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// store last sent speed and temp as update rate is slow
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float _last_temp;
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float _last_speed;
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// time last message was received
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uint32_t _last_update_ms;
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};
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#endif // AP_AIRSPEED_NMEA_ENABLED
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