mirror of https://github.com/ArduPilot/ardupilot
130 lines
3.5 KiB
C++
130 lines
3.5 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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#include "AP_RangeFinder_PWM.h"
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#include <AP_HAL/AP_HAL.h>
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#include <GCS_MAVLink/GCS.h>
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extern const AP_HAL::HAL& hal;
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/*
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The constructor also initialises the rangefinder.
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*/
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AP_RangeFinder_PWM::AP_RangeFinder_PWM(RangeFinder::RangeFinder_State &_state,
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AP_RangeFinder_Params &_params,
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float &_estimated_terrain_height) :
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AP_RangeFinder_Backend(_state, _params),
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estimated_terrain_height(_estimated_terrain_height)
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{
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}
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/*
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There's no sensible way of detecting a PWM rangefinder as the pins are configurable
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*/
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bool AP_RangeFinder_PWM::detect()
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{
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return true;
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}
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// read - return last value measured by sensor
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bool AP_RangeFinder_PWM::get_reading(uint16_t &reading_cm)
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{
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const uint32_t value_us = pwm_source.get_pwm_avg_us();
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if (value_us == 0) {
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return false;
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}
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reading_cm = value_us/10; // correct for LidarLite. Parameter needed? Converts from decimetres -> cm here
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return true;
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}
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bool AP_RangeFinder_PWM::check_pin()
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{
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if (!pwm_source.set_pin(params.pin, "RangeFinder_PWM")) {
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return false;
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}
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return true;
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}
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void AP_RangeFinder_PWM::check_stop_pin()
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{
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if (params.stop_pin == last_stop_pin) {
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return;
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}
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hal.gpio->pinMode(params.stop_pin, HAL_GPIO_OUTPUT);
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last_stop_pin = params.stop_pin;
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}
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bool AP_RangeFinder_PWM::check_pins()
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{
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check_stop_pin();
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return check_pin();
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}
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/*
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update the state of the sensor
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*/
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void AP_RangeFinder_PWM::update(void)
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{
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// check if pin has changed and configure interrupt handlers if required:
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if (!check_pins()) {
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return;
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}
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if (params.stop_pin != -1) {
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const bool oor = out_of_range();
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if (oor) {
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if (!was_out_of_range) {
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// we are above the power saving range. Disable the sensor
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hal.gpio->write(params.stop_pin, false);
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set_status(RangeFinder::Status::NoData);
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state.distance_cm = 0;
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state.voltage_mv = 0;
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was_out_of_range = oor;
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}
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return;
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}
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// re-enable the sensor:
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if (!oor && was_out_of_range) {
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hal.gpio->write(params.stop_pin, true);
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was_out_of_range = oor;
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}
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}
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if (!get_reading(state.distance_cm)) {
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// failure; consider changing our state
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if (AP_HAL::millis() - state.last_reading_ms > 200) {
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set_status(RangeFinder::Status::NoData);
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}
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return;
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}
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// add offset
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state.distance_cm += params.offset;
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// update range_valid state based on distance measured
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state.last_reading_ms = AP_HAL::millis();
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update_status();
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}
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// return true if we are beyond the power saving range
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bool AP_RangeFinder_PWM::out_of_range(void) const {
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return params.powersave_range > 0 && estimated_terrain_height > params.powersave_range;
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}
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