ardupilot/libraries/AP_WheelEncoder/WheelEncoder_Backend.cpp

60 lines
2.1 KiB
C++

/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <AP_Common/AP_Common.h>
#include <AP_HAL/AP_HAL.h>
#include "AP_WheelEncoder.h"
#include "WheelEncoder_Backend.h"
// base class constructor.
AP_WheelEncoder_Backend::AP_WheelEncoder_Backend(AP_WheelEncoder &frontend, uint8_t instance, AP_WheelEncoder::WheelEncoder_State &state) :
_frontend(frontend),
_state(state)
{
state.instance = instance;
}
// return pin. returns -1 if pin is not defined for this instance
int8_t AP_WheelEncoder_Backend::get_pin_a() const
{
if (_state.instance >= WHEELENCODER_MAX_INSTANCES) {
return -1;
}
return _frontend._pina[_state.instance].get();
}
// return pin. returns -1 if pin is not defined for this instance
int8_t AP_WheelEncoder_Backend::get_pin_b() const
{
if (_state.instance >= WHEELENCODER_MAX_INSTANCES) {
return -1;
}
return _frontend._pinb[_state.instance].get();
}
// copy state to front end helper function
void AP_WheelEncoder_Backend::copy_state_to_frontend(int32_t distance_count, uint32_t total_count, uint32_t error_count, uint32_t last_reading_ms)
{
// record distance and time change for calculating rate before previous state is overwritten
_state.dt_ms = last_reading_ms - _state.last_reading_ms;
_state.dist_count_change = distance_count - _state.distance_count;
// copy distance and error count so it is accessible to front end
_state.distance_count = distance_count;
_state.total_count = total_count;
_state.error_count = error_count;
_state.last_reading_ms = last_reading_ms;
}