mirror of https://github.com/ArduPilot/ardupilot
51 lines
1.4 KiB
C++
51 lines
1.4 KiB
C++
/*
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This program is free software: you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation, either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/*
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* analog airspeed driver
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*/
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#include <AP_HAL/AP_HAL.h>
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#include <AP_Common/AP_Common.h>
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#include "AP_Airspeed.h"
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#include "AP_Airspeed_analog.h"
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extern const AP_HAL::HAL &hal;
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// scaling for 3DR analog airspeed sensor
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#define VOLTS_TO_PASCAL 819
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AP_Airspeed_Analog::AP_Airspeed_Analog(AP_Airspeed &_frontend, uint8_t _instance) :
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AP_Airspeed_Backend(_frontend, _instance)
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{
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_source = hal.analogin->channel(get_pin());
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}
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bool AP_Airspeed_Analog::init()
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{
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return _source != nullptr;
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}
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// read the airspeed sensor
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bool AP_Airspeed_Analog::get_differential_pressure(float &pressure)
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{
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// allow pin to change
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if (_source == nullptr || !_source->set_pin(get_pin())) {
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return false;
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}
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pressure = _source->voltage_average_ratiometric() * VOLTS_TO_PASCAL / get_psi_range();
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return true;
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}
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