helloworld.cpp

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/*
 * rosserial Publisher Example for VEX Cortex
 * Prints "hello world!"
 *
 *
 *
 * Note: defining rosserial objects on the global scope will cause segmentation faults.
 * put variables in functons.
 */
 
#include <ros.h>
#include <std_msgs/String.h>
 
// this loop is run in setup function, which publishes  at 50hz.
inline void loop(ros::NodeHandle & nh, ros::Publisher & p, std_msgs::String & str_msg, char* msgdata)
{
  str_msg.data = msgdata;
  p.publish( &str_msg );
  nh.spinOnce();
  delay(20);
}
 
// The setup function will start a publisher on the topic "chatter" and begin publishing there.
inline void setup()
{
  // debug logging
  vexroslog("\n\n\n\n\r\t\tROSserial for VEX Cortex V2 - June 2018 - START\n\n\n\n\n\r");
 
  // make a node handle object, string message, and publisher for that message.
  ros::NodeHandle  nh;
  std_msgs::String str_msg;
  ros::Publisher chatter("chatter\0", &str_msg);
 
  // set up rosserial, and prepare to publish the chatter message 
  nh.initNode();
  nh.advertise(chatter);
 
  // message data variable.
  char* msg = (char*) malloc(20 * sizeof(char));
  while (1) {
 
    // send a message about the time!
    sprintf(msg, "[%d] Hello there!!", (int) millis());
    loop(nh, chatter, str_msg, msg);
  }
}