mirror of https://github.com/ArduPilot/ardupilot
122 lines
3.4 KiB
C++
122 lines
3.4 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/>.
|
|
*/
|
|
|
|
/*
|
|
* AP_RangeFinder_analog.cpp - rangefinder for analog source
|
|
*
|
|
*/
|
|
|
|
#include <AP_HAL/AP_HAL.h>
|
|
#include <AP_Common/AP_Common.h>
|
|
#include <AP_Math/AP_Math.h>
|
|
#include "RangeFinder.h"
|
|
#include "AP_RangeFinder_Params.h"
|
|
#include "AP_RangeFinder_analog.h"
|
|
|
|
extern const AP_HAL::HAL& hal;
|
|
|
|
/*
|
|
The constructor also initialises the rangefinder. Note that this
|
|
constructor is not called until detect() returns true, so we
|
|
already know that we should setup the rangefinder
|
|
*/
|
|
AP_RangeFinder_analog::AP_RangeFinder_analog(RangeFinder::RangeFinder_State &_state, AP_RangeFinder_Params &_params) :
|
|
AP_RangeFinder_Backend(_state, _params)
|
|
{
|
|
source = hal.analogin->channel(_params.pin);
|
|
if (source == nullptr) {
|
|
// failed to allocate a ADC channel? This shouldn't happen
|
|
set_status(RangeFinder::RangeFinder_NotConnected);
|
|
return;
|
|
}
|
|
set_status(RangeFinder::RangeFinder_NoData);
|
|
}
|
|
|
|
/*
|
|
detect if an analog rangefinder is connected. The only thing we
|
|
can do is check if the pin number is valid. If it is, then assume
|
|
that the device is connected
|
|
*/
|
|
bool AP_RangeFinder_analog::detect(AP_RangeFinder_Params &_params)
|
|
{
|
|
if (_params.pin != -1) {
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
|
|
/*
|
|
update raw voltage state
|
|
*/
|
|
void AP_RangeFinder_analog::update_voltage(void)
|
|
{
|
|
if (source == nullptr) {
|
|
state.voltage_mv = 0;
|
|
return;
|
|
}
|
|
// cope with changed settings
|
|
source->set_pin(params.pin);
|
|
if (params.ratiometric) {
|
|
state.voltage_mv = source->voltage_average_ratiometric() * 1000U;
|
|
} else {
|
|
state.voltage_mv = source->voltage_average() * 1000U;
|
|
}
|
|
}
|
|
|
|
/*
|
|
update distance_cm
|
|
*/
|
|
void AP_RangeFinder_analog::update(void)
|
|
{
|
|
update_voltage();
|
|
float v = state.voltage_mv * 0.001f;
|
|
float dist_m = 0;
|
|
float scaling = params.scaling;
|
|
float offset = params.offset;
|
|
RangeFinder::RangeFinder_Function function = (RangeFinder::RangeFinder_Function)params.function.get();
|
|
int16_t _max_distance_cm = params.max_distance_cm;
|
|
|
|
switch (function) {
|
|
case RangeFinder::FUNCTION_LINEAR:
|
|
dist_m = (v - offset) * scaling;
|
|
break;
|
|
|
|
case RangeFinder::FUNCTION_INVERTED:
|
|
dist_m = (offset - v) * scaling;
|
|
break;
|
|
|
|
case RangeFinder::FUNCTION_HYPERBOLA:
|
|
if (v <= offset) {
|
|
dist_m = 0;
|
|
} else {
|
|
dist_m = scaling / (v - offset);
|
|
}
|
|
if (dist_m > _max_distance_cm * 0.01f) {
|
|
dist_m = _max_distance_cm * 0.01f;
|
|
}
|
|
break;
|
|
}
|
|
if (dist_m < 0) {
|
|
dist_m = 0;
|
|
}
|
|
state.distance_cm = dist_m * 100.0f;
|
|
state.last_reading_ms = AP_HAL::millis();
|
|
|
|
// update range_valid state based on distance measured
|
|
update_status();
|
|
}
|
|
|