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             : #pragma once
      16             : 
      17             : #include "AP_Airspeed_config.h"
      18             : 
      19             : #if AP_AIRSPEED_AUAV_ENABLED
      20             : 
      21             : /*
      22             :   backend driver for airspeed from I2C
      23             :  */
      24             : 
      25             : #include <AP_HAL/AP_HAL.h>
      26             : #include <AP_HAL/I2CDevice.h>
      27             : #include <utility>
      28             : 
      29             : #include "AP_Airspeed_Backend.h"
      30             : 
      31             : class AUAV_Pressure_sensor
      32             : {
      33             : public:
      34             :     enum class Type {
      35             :         Differential,
      36             :         Absolute,
      37             :     };
      38             : 
      39             :     AUAV_Pressure_sensor(AP_HAL::Device *&_dev, Type _type);
      40             : 
      41             :     // start a measurement
      42             :     // Return true if successful
      43             :     bool measure() WARN_IF_UNUSED;
      44             : 
      45             :     enum class Status {
      46             :         Normal, // Happy, valid reading
      47             :         Busy, // Busy, try reading again later
      48             :         Fault, // Something bad has happened
      49             :     };
      50             : 
      51             :     // read the values from the sensor
      52             :     // Return status
      53             :     // pressure corrected but not scaled to the correct units
      54             :     // temperature in degrees centigrade
      55             :     Status collect(float &PComp, float &temperature) WARN_IF_UNUSED;
      56             : 
      57             :     // Read coefficients in stages
      58             :     enum class CoefficientStage {
      59             :         A_high,
      60             :         A_low,
      61             :         B_high,
      62             :         B_low,
      63             :         C_high,
      64             :         C_low,
      65             :         D_high,
      66             :         D_low,
      67             :         E_high,
      68             :         E_low,
      69             :         Done,
      70             :     } stage;
      71             : 
      72             :     // Read extended compensation coefficients from sensor
      73             :     void read_coefficients();
      74             : 
      75             :     // Read 4 bytes compensation coefficient
      76             :     bool read_register(uint8_t cmd, uint16_t &result);
      77             : 
      78             : private:
      79             :     AP_HAL::Device *&dev;
      80             : 
      81             :     Type type;
      82             : 
      83             :     // Extended compensation coefficients
      84             :     // Theses are read from the sensor in read_coefficients
      85             :     float LIN_A;
      86             :     float LIN_B;
      87             :     float LIN_C;
      88             :     float LIN_D;
      89             :     float Es;
      90             :     float TC50H;
      91             :     float TC50L;
      92             : 
      93             :     // Step of reading coefficients, request must be made before read.
      94             :     enum class CoefficientStep {
      95             :         request,
      96             :         read,
      97             :     } coefficient_step;
      98             : 
      99             : };
     100             : 
     101             : class AP_Airspeed_AUAV : public AP_Airspeed_Backend
     102             : {
     103             : public:
     104             :     AP_Airspeed_AUAV(AP_Airspeed &frontend, uint8_t _instance, const float _range_inH2O);
     105           0 :     ~AP_Airspeed_AUAV(void) {
     106           0 :         delete _dev;
     107           0 :     }
     108             : 
     109             :     // probe and initialise the sensor
     110             :     bool init() override;
     111             : 
     112             :     // return the current differential_pressure in Pascal
     113             :     bool get_differential_pressure(float &pressure) override;
     114             : 
     115             :     // return the current temperature in degrees C, if available
     116             :     bool get_temperature(float &temperature) override;
     117             : 
     118             : private:
     119             :     bool probe(uint8_t bus, uint8_t address);
     120             :     void _timer();
     121             : 
     122             :     uint32_t last_sample_time_ms;
     123             :     bool measurement_requested;
     124             :     AP_HAL::Device *_dev;
     125             : 
     126             :     AUAV_Pressure_sensor sensor { _dev, AUAV_Pressure_sensor::Type::Differential };
     127             : 
     128             :     float pressure;
     129             :     float temp_C;
     130             :     const float range_inH2O;
     131             : };
     132             : 
     133             : #endif  // AP_AIRSPEED_AUAV_ENABLED