ros_ultrasonic_1

#include <ros.h>
#include <std_msgs/String.h>
#include <std_msgs/Int32.h>
ros:: NodeHandle nh;
std_msgs::Int32 str_msg;
//std_msgs::String str_msg;
ros::Publisher chatter("chatter",&str_msg);
char hello[13]="hello world!";
#include <NewPing.h>
#define PIN_TRIG 12
#define PIN_ECHO 11
#define MAX_DISTANCE 200
NewPing sonar(PIN_TRIG, PIN_ECHO, MAX_DISTANCE);
void setup() {
  nh.initNode();
  nh.advertise(chatter);
 // Serial.begin(9600);

}

void loop() {
  //str_msg.data=hello;
  //str_msg.data = 15;
  chatter.publish(&str_msg);

  nh.spinOnce();
delay(50);

unsigned int distance = sonar.ping_cm();
char distanceString[16];
itoa(distance,distanceString,10);
str_msg.data = distance;

//Serial.print(distance);
//Serial.println("  cm");
}