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ROS Serial Arduino "Hello World" Error

asked 2021-08-24 13:06:31 -0600

matthewfwork gravatar image

Just getting rosserial setup after a few days of issues. When trying to run the Hello World example (code below) I error out (also below). Any help would be great!

 * rosserial Publisher Example
 * Prints "hello world!"

// Use the following line if you have a Leonardo or MKR1000
//#define USE_USBCON

#include <ros.h>
#include <std_msgs/String.h>

ros::NodeHandle nh;

std_msgs::String str_msg;
ros::Publisher chatter("chatter", &str_msg);

char hello[13] = "hello world!";

void setup()

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

Error code

Arduino: 1.8.15 (Linux), Board: "Arduino Uno"

Hello_world:2:14: error: expected constructor, destructor, or type conversion before 'Publisher'
  * rosserial Publisher Example
exit status 1
expected constructor, destructor, or type conversion before 'Publisher'

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.
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When trying to run the Hello World example

please, always link to whatever you are referring to.

We cannot see what you are seeing, so without a link, we have to spend time finding it ourselves, which means less time to help you solve your problem.

gvdhoorn gravatar image gvdhoorn  ( 2021-08-24 14:08:27 -0600 )edit

1 Answer

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answered 2021-08-24 14:07:38 -0600

gvdhoorn gravatar image

If this is a verbatim copy-paste, you have this:

 * rosserial Publisher Example
 * Prints "hello world!"

Note how the first line starts with a *.

It's very likely you made a mistake copying the example, and it should actually be /*, which would be the start of a multi-line comment.

A single star (*) on its own is not a legal character there, hence the compiler error.

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Asked: 2021-08-24 13:06:31 -0600

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Last updated: Aug 24 '21