Colony » Colony Scout

/**

 * 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 libmotors.cpp

 * @brief Contains motor declarations and functions

 * 

 * Contains functions and definitions for the use of

 * motors

 *

 * @author Colony Project, CMU Robotics Club

 **/

#include "libmotors.h"

/* ROS node created in libscout.cpp */

extern ros::NodeHandle libscout_node;

/** ROS publisher and client declaration */

ros::Publisher set_motors_publisher;

ros::ServiceClient query_motors_client;

/*!

 * \brief Initialize the motors module of libscout.

 *

 * Initialize the libscout node as a publisher of set_motors and a client of

 * query_motors.

 */

void libmotors_init()

{

  set_motors_publisher = libscout_node.advertise<motors::set_motors>("libmotors", 10);

  query_motors_client = libscout_node.serviceClient<motors::query_motors>("libmotors");

}

/*!

 * \brief Set motor speeds

 * Sets the speeds of the motors as a percentage of top speed. Can selectively

 * select which motors to set, and which to remain at previous speed.

 * \param speed The speed the motors should be set to

 * \param which A bitmask of which motors should be set

 * \return Function status

 */

int motors_set(int speed, int which, char units=MOTOR_PERCENT)

{

  /** \todo Set fields of the message based on params */

        motors::set_motors msg;

  if(!ros::ok())

        {

    return LIB_ERROR;

  }

  /* Set the speed for each motor according to the which bitmask*/

  if(which & MOTOR_FL_REV)

        {

    msg.fl_speed = -1 * speed;

  }

  if(which & MOTOR_FR_REV)

        {

    msg.fr_speed = -1 * speed;

  }

  if(which & MOTOR_BL_REV)

        {

    msg.bl_speed = -1 * speed;

  }

  if(which & MOTOR_BR_REV)

        {

    msg.br_speed = -1 * speed;

  }if(which & MOTOR_FL)

        {

    msg.fl_speed = speed;

  }

  if(which & MOTOR_FR)

        {

    msg.fr_speed = speed;

  }

  if(which & MOTOR_BL)

        {

    msg.bl_speed = speed;

  }

  if(which & MOTOR_BR)

        {

    msg.br_speed = speed;

  }

  /* Specify which units the speeds are given in */

  msg.units = units;

  /* Publishes message to set_motors topic */

  set_motors_publisher.publish(msg);

  ros::spinOnce();

  return LIB_OK;

}

/*!

 * \brief Query the current speeds of the motors

 *

 * Sends a request to the query_motors service which will reply with the

 *  current speed of each motor.

 *

 * \param which A bitmask that will specify which motor speed should be

 *  returned

 * \return The speed of the selected motor, or LIB_ERR if no motor selected

 */

int motors_query(int which)

{

  motors::query_motors srv;

  if(query_motors_client.call(srv))

        {

    switch(which)

                {

      case MOTOR_FL:

        return srv.response.fl_speed;

      case MOTOR_FR:

        return srv.response.fr_speed;

      case MOTOR_BL:

        return srv.response.bl_speed;

      case MOTOR_BR:

        return srv.response.br_speed;

      default:

        ROS_WARN("Bad WHICH in motors_query.");

        return LIB_ERROR;

    }

  }

        else

        {

    ROS_ERROR("Failed to call service query_motors");

    return LIB_ERROR;

  }

  return 0;

}