ardupilot/libraries/AP_Compass/AP_Compass_AK09916.cpp

180 lines
4.8 KiB
C++

/*
* This file 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 file 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/>.
*/
/*
Driver by Andrew Tridgell, Nov 2016
*/
#include "AP_Compass_AK09916.h"
#include <AP_HAL/AP_HAL.h>
#include <utility>
#include <AP_Math/AP_Math.h>
#include <stdio.h>
#define REG_COMPANY_ID 0x00
#define REG_DEVICE_ID 0x01
#define REG_ST1 0x10
#define REG_HXL 0x11
#define REG_HXH 0x12
#define REG_HYL 0x13
#define REG_HYH 0x14
#define REG_HZL 0x15
#define REG_HZH 0x16
#define REG_TMPS 0x17
#define REG_ST2 0x18
#define REG_CNTL1 0x30
#define REG_CNTL2 0x31
#define REG_CNTL3 0x32
extern const AP_HAL::HAL &hal;
AP_Compass_Backend *AP_Compass_AK09916::probe(Compass &compass,
AP_HAL::OwnPtr<AP_HAL::I2CDevice> dev,
bool force_external,
enum Rotation rotation)
{
if (!dev) {
return nullptr;
}
AP_Compass_AK09916 *sensor = new AP_Compass_AK09916(compass, std::move(dev), force_external, rotation);
if (!sensor || !sensor->init()) {
delete sensor;
return nullptr;
}
return sensor;
}
AP_Compass_AK09916::AP_Compass_AK09916(Compass &compass,
AP_HAL::OwnPtr<AP_HAL::Device> _dev,
bool _force_external,
enum Rotation _rotation)
: AP_Compass_Backend(compass)
, dev(std::move(_dev))
, force_external(_force_external)
, rotation(_rotation)
{
}
bool AP_Compass_AK09916::init()
{
if (!dev->get_semaphore()->take(0)) {
return false;
}
uint16_t whoami;
if (!dev->read_registers(REG_COMPANY_ID, (uint8_t *)&whoami, 2) ||
whoami != 0x0948) {
// not a AK09916
goto fail;
}
dev->setup_checked_registers(2);
dev->write_register(REG_CNTL2, 0x08, true); // continuous 100Hz
dev->write_register(REG_CNTL3, 0x00, true);
dev->get_semaphore()->give();
/* register the compass instance in the frontend */
compass_instance = register_compass();
printf("Found a AK09916 on 0x%x as compass %u\n", dev->get_bus_id(), compass_instance);
set_rotation(compass_instance, rotation);
if (force_external) {
set_external(compass_instance, true);
}
dev->set_device_type(DEVTYPE_AK09916);
set_dev_id(compass_instance, dev->get_bus_id());
// call timer() at 100Hz
dev->register_periodic_callback(10000,
FUNCTOR_BIND_MEMBER(&AP_Compass_AK09916::timer, bool));
return true;
fail:
dev->get_semaphore()->give();
return false;
}
bool AP_Compass_AK09916::timer()
{
struct PACKED {
int16_t magx;
int16_t magy;
int16_t magz;
uint8_t tmps;
uint8_t status2;
} data;
const float to_utesla = 4912.0f / 32752.0f;
const float utesla_to_milliGauss = 10;
const float range_scale = to_utesla * utesla_to_milliGauss;
Vector3f field;
// check data ready
uint8_t st1;
if (!dev->read_registers(REG_ST1, &st1, 1) || !(st1 & 1)) {
goto check_registers;
}
if (!dev->read_registers(REG_HXL, (uint8_t *)&data, sizeof(data))) {
goto check_registers;
}
field(data.magx * range_scale, data.magy * range_scale, data.magz * range_scale);
/* rotate raw_field from sensor frame to body frame */
rotate_field(field, compass_instance);
/* publish raw_field (uncorrected point sample) for calibration use */
publish_raw_field(field, AP_HAL::micros(), compass_instance);
/* correct raw_field for known errors */
correct_field(field, compass_instance);
if (_sem->take(0)) {
accum += field;
accum_count++;
_sem->give();
}
check_registers:
dev->check_next_register();
return true;
}
void AP_Compass_AK09916::read()
{
if (!_sem->take_nonblocking()) {
return;
}
if (accum_count == 0) {
_sem->give();
return;
}
accum /= accum_count;
publish_filtered_field(accum, compass_instance);
accum.zero();
accum_count = 0;
_sem->give();
}