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             :  *   analog airspeed driver
      17             :  */
      18             : 
      19             : #include "AP_Airspeed_analog.h"
      20             : 
      21             : #if AP_AIRSPEED_ANALOG_ENABLED
      22             : 
      23             : #include <AP_HAL/AP_HAL.h>
      24             : #include <AP_Common/AP_Common.h>
      25             : 
      26             : #include "AP_Airspeed.h"
      27             : 
      28             : extern const AP_HAL::HAL &hal;
      29             : 
      30             : // scaling for 3DR analog airspeed sensor
      31             : #define VOLTS_TO_PASCAL 819
      32             : 
      33         690 : AP_Airspeed_Analog::AP_Airspeed_Analog(AP_Airspeed &_frontend, uint8_t _instance) :
      34         690 :     AP_Airspeed_Backend(_frontend, _instance)
      35             : {
      36         690 :     _source = hal.analogin->channel(get_pin());
      37         690 : }
      38             : 
      39         690 : bool AP_Airspeed_Analog::init()
      40             : {
      41         690 :     set_bus_id(AP_HAL::Device::make_bus_id(
      42             :         AP_HAL::Device::BUS_TYPE_UNKNOWN,
      43             :         0,
      44             :         0,
      45             :         uint8_t(DevType::ANALOG)
      46             :     ));
      47         690 :     return _source != nullptr;
      48             : }
      49             : 
      50             : // read the airspeed sensor
      51      552072 : bool AP_Airspeed_Analog::get_differential_pressure(float &pressure)
      52             : {
      53             :     // allow pin to change
      54      552072 :     if (_source == nullptr || !_source->set_pin(get_pin())) {
      55           0 :         return false;
      56             :     }
      57      552072 :     pressure = _source->voltage_average_ratiometric() * VOLTS_TO_PASCAL / get_psi_range();
      58      552072 :     return true;
      59             : }
      60             : 
      61             : #endif  // AP_AIRSPEED_ANALOG_ENABLED