laptop_battery_node.cpp

Go to the documentation of this file.

/*********************************************************************
*
* Software License Agreement (BSD License)
*
*  Copyright (c) 2010, ISR University of Coimbra.
*  All rights reserved.
*
*  Redistribution and use in source and binary forms, with or without
*  modification, are permitted provided that the following conditions
*  are met:
*
*   * Redistributions of source code must retain the above copyright
*     notice, this list of conditions and the following disclaimer.
*   * Redistributions in binary form must reproduce the above
*     copyright notice, this list of conditions and the following
*     disclaimer in the documentation and/or other materials provided
*     with the distribution.
*   * Neither the name of the ISR University of Coimbra nor the names of its
*     contributors may be used to endorse or promote products derived
*     from this software without specific prior written permission.
*
*  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
*  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
*  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
*  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
*  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
*  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
*  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
*  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
*  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
*  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
*  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
*  POSSIBILITY OF SUCH DAMAGE.
*
* Author: Gonçalo Cabrita on 01/03/2011
*********************************************************************/
#include <stdlib.h>
#include <stdio.h>

#include <ros/ros.h>
#include <laptop_battery/Battery.h>


int main(int argc, char** argv)
{
        ros::init(argc, argv, "laptop_battery_node");
        ros::NodeHandle n;
        
        ROS_INFO("LaptopBattery for ROS v0.1");
        
        ros::Publisher pub = n.advertise<laptop_battery::Battery>("/laptop/battery", 10);
        
        char description[128];
        char value[128];
        
        int full_capacity;
        int remaining_capacity;
        int present_rate;
        
        laptop_battery::Battery bat_msg;
        
        ros::Rate r(1.0);
        while(n.ok())
        {       
                FILE * state = fopen("/proc/acpi/battery/BAT0/state", "r");
                FILE * info = fopen("/proc/acpi/battery/BAT0/info", "r");
        
                if(state && info)
                {
                        while(!feof(state))
                        {
                                fscanf(state, "%[^:]:%[^\n]\n", description, value);
                        
                                //ROS_INFO("%s %s", description, value);
                        
                                if(strcmp(description, "remaining capacity")==0)
                                {
                                        remaining_capacity = atoi(value);
                                }
                                else if(strcmp(description, "present rate")==0)
                                {
                                        present_rate = atoi(value);
                                }
                                else if(strcmp(description, "charging state")==0)
                                {
                                        std::string charge = value;
                                        size_t i = charge.find_last_of(' ');
                                        
                                        if(charge.compare(i+1, charge.length()-i+1, "discharging")==0) bat_msg.charging = false;
                                        else bat_msg.charging = true;
                                }
                        }
                        
                        while(!feof(info))
                        {
                                fscanf(info, "%[^:]:%[^\n]\n", description, value);
                                
                                //ROS_INFO("%s %s", description, value);
                        
                                if(strcmp(description, "last full capacity")==0)
                                {
                                        full_capacity = atoi(value);
                                }
                        }
                        
                        if(full_capacity > 0) bat_msg.level = (float)(remaining_capacity*100.0/full_capacity);
                        else ROS_ERROR("LaptopBattery -- Error calculating the battery level!");
                        
                        if(present_rate <= 0 || bat_msg.charging == true) bat_msg.time_remaining = 0;
                        else bat_msg.time_remaining = (int)(remaining_capacity/present_rate*60);
                        
                        bat_msg.header.stamp = ros::Time::now();
                        
                        pub.publish(bat_msg);
                }
                else
                {
                        ROS_FATAL("LaptopBattery -- Failed to read the battery info!");
                        ROS_BREAK();
                }
                
                fclose(state);
                fclose(info);
        
                ros::spinOnce();
                r.sleep();
                
                //rewind(state);
                //rewind(info);
        }

        return(0);
}

// EOF