ROS Programming: Building Powerful Robots

Understanding ROS node APIs in Arduino

Following is a basic structure ROS Arduino node. We can see the function of each line of code:

#include <ros.h> 
 
ros::NodeHandle nh; 
 
void setup() 
{ 
  nh.initNode(); 
} 
 
void loop() 
{ 
  nh.spinOnce(); 
} 

Creating of NodeHandle in Arduino is done using the following line of code:

ros::NodeHandle nh; 

Note that Nodehandle should be declared before the setup() function, which will give a global scope to the NodeHandle instance called nh. The initialization of this node is done inside the setup() function.

  nh.initNode(); 

The Arduino setup() function will execute only once when the device starts, and note that we can only create one node from a serial device.

Inside the loop() function, we have to use the following ...