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/**

 * Copyright (c) 2011 Colony Project

 * 

 * Permission is hereby granted, free of charge, to any person

 * obtaining a copy of this software and associated documentation

 * files (the "Software"), to deal in the Software without

 * restriction, including without limitation the rights to use,

 * copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following

 * conditions:

 * 

 * The above copyright notice and this permission notice shall be

 * included in all copies or substantial portions of the Software.

 * 

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES

 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,

 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

 * OTHER DEALINGS IN THE SOFTWARE.

 **/

/**

 * @file motors.cpp

 * @brief Contains code to control the motors.

 *

 * Implementation of functions for motor use.

 *

 * @author Colony Project, CMU Robotics Club

 * @author Benjamin Wasserman

 **/

#include "ros/ros.h"

#include "motors.h"

//#include "libscout/src/constants.h"

#include <cstdlib>

/**

 * @defgroup motors Motors

 * @brief Functions for using the motors

 *

 * @{

 **/

/* Motor state variables

 * Speeds expressed as absolute speed out of max speed (0 - +-MAXSPEED)

 * Absolute speed is the speed written to the hardware to move the motors

 */

/** @todo Fix types: static */

int motor_fl_speed; /**< The current speed of the front left motor. */

int motor_fr_speed; /**< The current speed of the front right motor. */

int motor_bl_speed; /**< The current speed of the back left motor. */

int motor_br_speed; /**< The current speed of the back right motor. */

/**

 * @brief Sets motor speed

 *

 * Sets the motor speeds based on subscription to the set_motors topic.

 *

 * @param msg The message from the set_motors topic, containing speeds and

 *  motor configuration settings.

 */

void motors_set(const motors::set_motors::ConstPtr& msg)

{

    /** @todo Edit to only set requested motors, not all */

    int which = msg->which;

    if(which & MOTOR_FL_REV)

    {

      motor_fl_speed = -1 * motors_rel_to_abs(msg->fl_speed, msg->units);

    }

    if(which & MOTOR_FR_REV)

    {

      motor_fr_speed = -1 * motors_rel_to_abs(msg->fr_speed, msg->units);

    }

    if(which & MOTOR_BL_REV)

    {

      motor_bl_speed = -1 * motors_rel_to_abs(msg->bl_speed, msg->units);

    }

    if(which & MOTOR_BR_REV)

    {

      motor_br_speed = -1 * motors_rel_to_abs(msg->br_speed, msg->units);

    }

    if(which & MOTOR_FL)

    {

      motor_fl_speed = motors_rel_to_abs(msg->fl_speed, msg->units);

    }

    if(which & MOTOR_FR)

    {

      motor_fr_speed = motors_rel_to_abs(msg->fr_speed, msg->units);

    }

    if(which & MOTOR_BL)

    {

      motor_bl_speed = motors_rel_to_abs(msg->bl_speed, msg->units);

    }

    if(which & MOTOR_BR)

    {

      motor_br_speed = motors_rel_to_abs(msg->br_speed, msg->units);

    }

    /* Write speeds to hardware */

    /** @todo Add code to write speeds to hardware */

}

/**

 * @brief Outputs current motor speeds

 *

 * Serves the service query_motors by responding to service requests with the

 * speeds of the motors.

 * @param req The request. The only field is the units requested.

 * @param res The response. The fields will be filled with values.

 */

bool motors_query(motors::query_motors::Request &req,

                  motors::query_motors::Response &res)

{

    int units = req.units;

    res.fl_speed = motors_abs_to_rel(motor_fl_speed, units);

    res.fr_speed = motors_abs_to_rel(motor_fr_speed, units);

    res.bl_speed = motors_abs_to_rel(motor_bl_speed, units);

    res.br_speed = motors_abs_to_rel(motor_br_speed, units);

    ROS_DEBUG("Motor speeds queried");

    return true;

}

/**

 * @brief Converts set speeds (of various units) to absolute speeds.

 *

 * @param speed The speed expressed in the desired units

 * @param units The units the desired speed is measured in

 * @return The absolute speed of the motor

 **/

int motors_rel_to_abs(int rel_speed, int units)

{

    switch(units)

    {

      case MOTOR_ABSOLUTE:/* Speed given as absolute */

        return rel_speed;

      case MOTOR_PERCENT:/* Convert from percentage */

        return rel_speed * MAXSPEED / 100;

      case MOTOR_MMS:/* Convert from mm/s */

        /** @todo Make math to do this conversion **/

        return rel_speed;

      case MOTOR_CMS:/* Convert from cm/s */

        /** @todo Make math to do this conversion **/

        return rel_speed;

      default: /* The units aren't recognized */

        /** @todo Decide on default case. Either percent or absolute. **/

        return rel_speed;

    }

}

/**

 * @brief Convert absolute speeds to speeds of various units.

 *

 * @param speed The speed expressed in absolute units.

 * @param units The units the desired speed is measured in.

 * @return The relative speed of the motor in desired units.

 **/

int motors_abs_to_rel(int abs_speed, int units)

{

    switch(units)

    {

      case MOTOR_ABSOLUTE:/* Speed given as absolute */

        return abs_speed;

      case MOTOR_PERCENT:/* Convert from percentage */

        return abs_speed * 100 / MAXSPEED;

      case MOTOR_MMS:/* Convert from mm/s */

        /** @todo Make math to do this conversion **/

        return abs_speed;

      case MOTOR_CMS:/* Convert from cm/s */

        /** @todo Make math to do this conversion **/

        return abs_speed;

      default: /* The units aren't recognized */

        /** @todo Decide on default case. Either percent or absolute. **/

        return abs_speed;

    }

}

/**

 * @brief Motors driver. This is a ROS node that controls motor speeds.

 *

 * This is the main function for the motors node. It is run when the node

 * starts and initializes the motors. It then subscribes to the

 * set_motors, and set_motor_speeds topics, and advertises the

 * query_motors service.

 * 

 * @param argc The number of command line arguments (should be 1)

 * @param argv The array of command line arguments

 **/

int main(int argc, char **argv)

{

    /* Initialize in ROS the motors driver node */

    ros::init(argc, argv, "motors_driver");

    /* Advertise that this serves the query_motors service */

    ros::NodeHandle n;

    ros::ServiceServer service = n.advertiseService("query_motors",

                                                    motors_query);

    /* Subscribe to the set_motors topic */

    ros::Subscriber sub0 = n.subscribe("set_motors", QUEUE_SIZE, motors_set);

    /* Initialize hardware for motors */

    // Hardware init functions here

    ROS_INFO("Ready to set motors.");

    ros::spin();

    return 0;

}

/** @} **/