joy_node.cpp

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/*
 * teleop_pr2
 * Copyright (c) 2009, Willow Garage, Inc.
 * 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 <ORGANIZATION> 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: Blaise Gassend

#include <unistd.h>
#include <math.h>
#include <linux/joystick.h>
#include <fcntl.h>
#include <diagnostic_updater/diagnostic_updater.h>
#include "ros/ros.h"
#include <sensor_msgs/Joy.h>


class Joystick
{
private:
  ros::NodeHandle nh_;
  bool open_;               
  std::string joy_dev_;
  double deadzone_;
  double autorepeat_rate_;  // in Hz.  0 for no repeat.
  double coalesce_interval_; // Defaults to 100 Hz rate limit.
  int event_count_;
  int pub_count_;
  ros::Publisher pub_;
  double lastDiagTime_;
  
  diagnostic_updater::Updater diagnostic_;
  
  void diagnostics(diagnostic_updater::DiagnosticStatusWrapper& stat)
  {
    double now = ros::Time::now().toSec();
    double interval = now - lastDiagTime_;
    if (open_)
      stat.summary(0, "OK");
    else
      stat.summary(2, "Joystick not open.");
    
    stat.add("topic", pub_.getTopic());
    stat.add("device", joy_dev_);
    stat.add("dead zone", deadzone_);
    stat.add("autorepeat rate (Hz)", autorepeat_rate_);
    stat.add("coalesce interval (s)", coalesce_interval_);
    stat.add("recent joystick event rate (Hz)", event_count_ / interval);
    stat.add("recent publication rate (Hz)", pub_count_ / interval);
    stat.add("subscribers", pub_.getNumSubscribers());
    event_count_ = 0;
    pub_count_ = 0;
    lastDiagTime_ = now;
  }
  
public:
  Joystick() : nh_(), diagnostic_()
  {}
  
  int main(int argc, char **argv)
  {
    diagnostic_.add("Joystick Driver Status", this, &Joystick::diagnostics);
    diagnostic_.setHardwareID("none");

    // Parameters
    ros::NodeHandle nh_param("~");
    pub_ = nh_.advertise<sensor_msgs::Joy>("joy", 1);
    nh_param.param<std::string>("dev", joy_dev_, "/dev/input/js0");
    nh_param.param<double>("deadzone", deadzone_, 0.05);
    nh_param.param<double>("autorepeat_rate", autorepeat_rate_, 0);
    nh_param.param<double>("coalesce_interval", coalesce_interval_, 0.001);
    
    // Checks on parameters
    if (autorepeat_rate_ > 1 / coalesce_interval_)
      ROS_WARN("joy_node: autorepeat_rate (%f Hz) > 1/coalesce_interval (%f Hz) does not make sense. Timing behavior is not well defined.", autorepeat_rate_, 1/coalesce_interval_);
    
    if (deadzone_ >= 1)
    {
      ROS_WARN("joy_node: deadzone greater than 1 was requested. The semantics of deadzone have changed. It is now related to the range [-1:1] instead of [-32767:32767]. For now I am dividing your deadzone by 32767, but this behavior is deprecated so you need to update your launch file.");
      deadzone_ /= 32767;
    }
    
    if (deadzone_ > 0.9)
    {
      ROS_WARN("joy_node: deadzone (%f) greater than 0.9, setting it to 0.9", deadzone_);
      deadzone_ = 0.9;
    }
    
    if (deadzone_ < 0)
    {
      ROS_WARN("joy_node: deadzone_ (%f) less than 0, setting to 0.", deadzone_);
      deadzone_ = 0;
    }

    if (autorepeat_rate_ < 0)
    {
      ROS_WARN("joy_node: autorepeat_rate (%f) less than 0, setting to 0.", autorepeat_rate_);
      autorepeat_rate_ = 0;
    }
    
    if (coalesce_interval_ < 0)
    {
      ROS_WARN("joy_node: coalesce_interval (%f) less than 0, setting to 0.", coalesce_interval_);
      coalesce_interval_ = 0;
    }
    
    // Parameter conversions
    double autorepeat_interval = 1 / autorepeat_rate_;
    double scale = -1. / (1. - deadzone_) / 32767.;
    double unscaled_deadzone = 32767. * deadzone_;

    js_event event;
    struct timeval tv;
    fd_set set;
    int joy_fd;
    event_count_ = 0;
    pub_count_ = 0;
    lastDiagTime_ = ros::Time::now().toSec();
    
    // Big while loop opens, publishes
    while (nh_.ok())
    {                                      
      open_ = false;
      diagnostic_.force_update();
      bool first_fault = true;
      while (true)
      {
        ros::spinOnce();
        if (!nh_.ok())
          goto cleanup;
        joy_fd = open(joy_dev_.c_str(), O_RDONLY);
        if (joy_fd != -1)
        {
          // There seems to be a bug in the driver or something where the
          // initial events that are to define the initial state of the
          // joystick are not the values of the joystick when it was opened
          // but rather the values of the joystick when it was last closed.
          // Opening then closing and opening again is a hack to get more
          // accurate initial state data.
          close(joy_fd);
          joy_fd = open(joy_dev_.c_str(), O_RDONLY);
        }
        if (joy_fd != -1)
          break;
        if (first_fault)
        {
          ROS_ERROR("Couldn't open joystick %s. Will retry every second.", joy_dev_.c_str());
          first_fault = false;
        }
        sleep(1.0);
        diagnostic_.update();
      }
      
      ROS_INFO("Opened joystick: %s. deadzone_: %f.", joy_dev_.c_str(), deadzone_);
      open_ = true;
      diagnostic_.force_update();
      
      bool tv_set = false;
      bool publication_pending = false;
      tv.tv_sec = 1;
      tv.tv_usec = 0;
      sensor_msgs::Joy joy_msg; // Here because we want to reset it on device close.
      while (nh_.ok()) 
      {
        ros::spinOnce();
        
        bool publish_now = false;
        bool publish_soon = false;
        FD_ZERO(&set);
        FD_SET(joy_fd, &set);
        
        //ROS_INFO("Select...");
        int select_out = select(joy_fd+1, &set, NULL, NULL, &tv);
        //ROS_INFO("Tick...");
        if (select_out == -1)
        {
          tv.tv_sec = 0;
          tv.tv_usec = 0;
          //ROS_INFO("Select returned negative. %i", ros::isShuttingDown());
          continue;
          //                            break; // Joystick is probably closed. Not sure if this case is useful.
        }
        
        if (FD_ISSET(joy_fd, &set))
        {
          if (read(joy_fd, &event, sizeof(js_event)) == -1 && errno != EAGAIN)
            break; // Joystick is probably closed. Definitely occurs.
          
          //ROS_INFO("Read data...");
          joy_msg.header.stamp = ros::Time().now();
          event_count_++;
          switch(event.type)
          {
          case JS_EVENT_BUTTON:
          case JS_EVENT_BUTTON | JS_EVENT_INIT:
            if(event.number >= joy_msg.buttons.size())
            {
              int old_size = joy_msg.buttons.size();
              joy_msg.buttons.resize(event.number+1);
              for(unsigned int i=old_size;i<joy_msg.buttons.size();i++)
                joy_msg.buttons[i] = 0.0;
            }
            joy_msg.buttons[event.number] = (event.value ? 1 : 0);
            // For initial events, wait a bit before sending to try to catch
            // all the initial events.
            if (!(event.type & JS_EVENT_INIT))
              publish_now = true;
            else
              publish_soon = true;
            break;
          case JS_EVENT_AXIS:
          case JS_EVENT_AXIS | JS_EVENT_INIT:
            if(event.number >= joy_msg.axes.size())
            {
              int old_size = joy_msg.axes.size();
              joy_msg.axes.resize(event.number+1);
              for(unsigned int i=old_size;i<joy_msg.axes.size();i++)
                joy_msg.axes[i] = 0.0;
            }
            if (!(event.type & JS_EVENT_INIT)) // Init event.value is wrong.
            {
              double val = event.value;
              // Allows deadzone to be "smooth"
              if (val > unscaled_deadzone)
                val -= unscaled_deadzone;
              else if (val < -unscaled_deadzone)
                val += unscaled_deadzone;
              else
                val = 0;
              joy_msg.axes[event.number] = val * scale;
            }
            // Will wait a bit before sending to try to combine events.                                 
            publish_soon = true;
            break;
          default:
            ROS_WARN("joy_node: Unknown event type. Please file a ticket. time=%u, value=%d, type=%Xh, number=%d", event.time, event.value, event.type, event.number);
            break;
          }
        }
        else if (tv_set) // Assume that the timer has expired.
          publish_now = true;
        
        if (publish_now)
        {
          // Assume that all the JS_EVENT_INIT messages have arrived already.
          // This should be the case as the kernel sends them along as soon as
          // the device opens.
          //ROS_INFO("Publish...");
          pub_.publish(joy_msg);
          publish_now = false;
          tv_set = false;
          publication_pending = false;
          publish_soon = false;
          pub_count_++;
        }
        
        // If an axis event occurred, start a timer to combine with other
        // events.
        if (!publication_pending && publish_soon)
        {
          tv.tv_sec = trunc(coalesce_interval_);
          tv.tv_usec = (coalesce_interval_ - tv.tv_sec) * 1e6;
          publication_pending = true;
          tv_set = true;
          //ROS_INFO("Pub pending...");
        }
        
        // If nothing is going on, start a timer to do autorepeat.
        if (!tv_set && autorepeat_rate_ > 0)
        {
          tv.tv_sec = trunc(autorepeat_interval);
          tv.tv_usec = (autorepeat_interval - tv.tv_sec) * 1e6; 
          tv_set = true;
          //ROS_INFO("Autorepeat pending... %i %i", tv.tv_sec, tv.tv_usec);
        }
        
        if (!tv_set)
        {
          tv.tv_sec = 1;
          tv.tv_usec = 0;
        }
        
        diagnostic_.update();
      } // End of joystick open loop.
      
      close(joy_fd);
      ros::spinOnce();
      if (nh_.ok())
        ROS_ERROR("Connection to joystick device lost unexpectedly. Will reopen.");
    }
    
  cleanup:
    ROS_INFO("joy_node shut down.");
    
    return 0;
  }
};

int main(int argc, char **argv)
{
  ros::init(argc, argv, "joy_node");
  Joystick j;
  return j.main(argc, argv);
}