/// -*- 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 .
*/
/*
* AP_OpticalFlow_PX4.cpp - ardupilot library for PX4Flow sensor
*
*/
#include
#include "OpticalFlow.h"
#if CONFIG_HAL_BOARD == HAL_BOARD_PX4 || CONFIG_HAL_BOARD == HAL_BOARD_VRBRAIN
#include
#include
#include
#include
#include
#include
extern const AP_HAL::HAL& hal;
AP_OpticalFlow_PX4::AP_OpticalFlow_PX4(OpticalFlow &_frontend) :
OpticalFlow_backend(_frontend)
{}
void AP_OpticalFlow_PX4::init(void)
{
_fd = open(PX4FLOW0_DEVICE_PATH, O_RDONLY);
// check for failure to open device
if (_fd == -1) {
return;
}
// change to 10Hz update
if (ioctl(_fd, SENSORIOCSPOLLRATE, 10) != 0) {
hal.console->printf("Unable to set flow rate to 10Hz\n");
}
}
// update - read latest values from sensor and fill in x,y and totals.
void AP_OpticalFlow_PX4::update(void)
{
// return immediately if not initialised
if (_fd == -1) {
return;
}
struct optical_flow_s report;
while (::read(_fd, &report, sizeof(optical_flow_s)) == sizeof(optical_flow_s) &&
report.timestamp != _last_timestamp) {
struct OpticalFlow::OpticalFlow_state state;
state.device_id = report.sensor_id;
state.surface_quality = report.quality;
if (report.integration_timespan > 0) {
float yawAngleRad = _yawAngleRad();
float cosYaw = cosf(yawAngleRad);
float sinYaw = sinf(yawAngleRad);
const Vector2f flowScaler = _flowScaler();
float flowScaleFactorX = 1.0f + 0.001f * flowScaler.x;
float flowScaleFactorY = 1.0f + 0.001f * flowScaler.y;
float integralToRate = 1e6f / float(report.integration_timespan);
// rotate sensor measurements from sensor to body frame through sensor yaw angle
state.flowRate.x = flowScaleFactorX * integralToRate * (cosYaw * float(report.pixel_flow_x_integral) - sinYaw * float(report.pixel_flow_y_integral)); // rad/sec measured optically about the X body axis
state.flowRate.y = flowScaleFactorY * integralToRate * (sinYaw * float(report.pixel_flow_x_integral) + cosYaw * float(report.pixel_flow_y_integral)); // rad/sec measured optically about the Y body axis
state.bodyRate.x = integralToRate * (cosYaw * float(report.gyro_x_rate_integral) - sinYaw * float(report.gyro_y_rate_integral)); // rad/sec measured inertially about the X body axis
state.bodyRate.y = integralToRate * (sinYaw * float(report.gyro_x_rate_integral) + cosYaw * float(report.gyro_y_rate_integral)); // rad/sec measured inertially about the Y body axis
} else {
state.flowRate.zero();
state.bodyRate.zero();
}
_last_timestamp = report.timestamp;
_update_frontend(state);
}
}
#endif // CONFIG_HAL_BOARD == HAL_BOARD_PX4