mirror of https://github.com/ArduPilot/ardupilot
124 lines
3.8 KiB
C++
124 lines
3.8 KiB
C++
// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
|
|
/*
|
|
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_PulsedLightLRF.cpp - Arduino Library for Pulsed Light's Laser Range Finder
|
|
* Code by Randy Mackay. DIYDrones.com
|
|
*
|
|
* Sensor should be connected to the I2C port
|
|
*
|
|
* Variables:
|
|
* bool healthy : indicates whether last communication with sensor was successful
|
|
*
|
|
* Methods:
|
|
* take_reading(): ask the sonar to take a new distance measurement
|
|
* read() : read last distance measured (in cm)
|
|
*
|
|
*/
|
|
|
|
#include "AP_RangeFinder_PulsedLightLRF.h"
|
|
#include <AP_HAL.h>
|
|
|
|
extern const AP_HAL::HAL& hal;
|
|
|
|
// Constructor //////////////////////////////////////////////////////////////
|
|
|
|
AP_RangeFinder_PulsedLightLRF::AP_RangeFinder_PulsedLightLRF(FilterInt16 *filter) :
|
|
RangeFinder(NULL, filter),
|
|
healthy(true),
|
|
_addr(AP_RANGEFINDER_PULSEDLIGHTLRF_ADDR)
|
|
{
|
|
min_distance = AP_RANGEFINDER_PULSEDLIGHTLRF_MIN_DISTANCE;
|
|
max_distance = AP_RANGEFINDER_PULSEDLIGHTLRF_MAX_DISTANCE;
|
|
}
|
|
|
|
// Public Methods //////////////////////////////////////////////////////////////
|
|
|
|
// init - simply sets the i2c address
|
|
void AP_RangeFinder_PulsedLightLRF::init(uint8_t address)
|
|
{
|
|
// set sensor i2c address
|
|
_addr = address;
|
|
}
|
|
|
|
// take_reading - ask sensor to make a range reading
|
|
bool AP_RangeFinder_PulsedLightLRF::take_reading()
|
|
{
|
|
// get pointer to i2c bus semaphore
|
|
AP_HAL::Semaphore* i2c_sem = hal.i2c->get_semaphore();
|
|
|
|
// exit immediately if we can't take the semaphore
|
|
if (i2c_sem == NULL || !i2c_sem->take(5)) {
|
|
healthy = false;
|
|
return healthy;
|
|
}
|
|
|
|
// send command to take reading
|
|
if (hal.i2c->writeRegister(_addr, AP_RANGEFINDER_PULSEDLIGHTLRF_COMMAND_REG, AP_RANGEFINDER_PULSEDLIGHTLRF_CMDREG_ACQUISITION) != 0) {
|
|
healthy = false;
|
|
}else{
|
|
healthy = true;
|
|
}
|
|
|
|
// return semaphore
|
|
i2c_sem->give();
|
|
|
|
return healthy;
|
|
}
|
|
|
|
// read - return last value measured by sensor
|
|
int16_t AP_RangeFinder_PulsedLightLRF::read()
|
|
{
|
|
uint8_t buff[2];
|
|
int16_t ret_value = 0;
|
|
|
|
// get pointer to i2c bus semaphore
|
|
AP_HAL::Semaphore* i2c_sem = hal.i2c->get_semaphore();
|
|
|
|
// exit immediately if we can't take the semaphore
|
|
if (i2c_sem == NULL || !i2c_sem->take(5)) {
|
|
healthy = false;
|
|
return healthy;
|
|
}
|
|
|
|
// assume the worst
|
|
healthy = false;
|
|
|
|
// read the high byte
|
|
if (hal.i2c->readRegisters(_addr, AP_RANGEFINDER_PULSEDLIGHTLRF_DISTHIGH_REG, 1, &buff[0]) == 0) {
|
|
// read the low byte
|
|
if (hal.i2c->readRegisters(_addr, AP_RANGEFINDER_PULSEDLIGHTLRF_DISTLOW_REG, 1, &buff[1]) == 0) {
|
|
healthy = true;
|
|
// combine results into distance
|
|
ret_value = buff[0] << 8 | buff[1];
|
|
}
|
|
}
|
|
|
|
// ensure distance is within min and max
|
|
ret_value = constrain_int16(ret_value, min_distance, max_distance);
|
|
ret_value = _mode_filter->apply(ret_value);
|
|
|
|
// return semaphore
|
|
i2c_sem->give();
|
|
|
|
// kick off another reading for next time
|
|
// To-Do: replace this with continuous mode
|
|
take_reading();
|
|
|
|
// to-do: do we really want to return 0 if reading the distance fails?
|
|
return ret_value;
|
|
}
|