Ardupilot2/libraries/AP_IRLock/IRLock.h

/*
   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/>.
 */

/*
 * IRLock.h - IRLock Base Class for Ardupilot
 *
 *  Created on: Nov 10, 2014
 *      Author: MLandes
 */

#ifndef __IRLOCK_H__
#define __IRLOCK_H__

#include <AP_AHRS/AP_AHRS.h>

#define IRLOCK_MAX_BLOCKS_PER_FRAME 5      // max number of blobs that can be detected by IR-LOCK sensor (should match PX4Firmware's irlock driver's IRLOCK_OBJECTS_MAX)
#define IRLOCK_CENTER_X  159               // the center x pixel value
#define IRLOCK_CENTER_Y  99                // the center y pixel value
#define IRLOCK_NOBLOB_FRAME 10             // the number of consecutive similar frames that will cause the sensor validity variable to turn false
#define IRLOCK_X_PIXEL_PER_DEGREE 5.374f   // the x pixel to angle calibration variable
#define IRLOCK_Y_PIXEL_PER_DEGREE 5.698f   // the y pixel to angle calibration variable
#define IRLOCK_TIMEOUT_MS   100             // remove all blocks if no data received within 0.1 seconds

typedef struct {
	uint16_t signature;
	uint16_t center_x;
	uint16_t center_y;
	uint16_t width;
	uint16_t height;
} irlock_block;

class IRLock
{
public:
	IRLock();
	virtual ~IRLock();

	// init - initialize sensor library
	// library won't be useable unless this is first called
	virtual void init() = 0;

	// true if irlock sensor is online and healthy
	bool healthy() const { return _flags.healthy; }

	// timestamp of most recent data read from the sensor
	uint32_t last_update() const { return _last_update; }

	// returns the number of blocks in the current frame
	size_t num_blocks() const { return _num_blocks; }

	// retrieve latest sensor data - returns true if new data is available
	virtual bool update() = 0;

	// get_angle_to_target - retrieve body frame x and y angles (in radians) to target
	//  returns true if angles are available, false if not (i.e. no target)
	bool get_angle_to_target(float &x_angle_rad, float &y_angle_rad) const;

protected:
	struct AP_IRLock_Flags {
		uint8_t healthy : 1; // true if sensor is healthy
	} _flags;

	// internals
	uint32_t _last_update;
	uint16_t _num_blocks;
	irlock_block _current_frame[IRLOCK_MAX_BLOCKS_PER_FRAME];
};


#endif /* __IRLOCK_H__ */