Do you know how a robot makes decisions according to its sensor data? It has a processing unit, right? The processing unit can be either a computer or a microcontroller. We are using high-end computers to process data if the robot has sensors such as camera, laser scanners, and LIDARs. On the other hand, microcontrollers are commonly used in all kind of robots for interfacing low-bandwidth sensors and for performing real-time tasks. Both these units are commonly found in a standard robotic system.

In small robots such as line follower, we may do everything using a single controller. The sensors such as ultrasonic distance sensors, Imus can easily interface with a microcontroller. So in a robotic system, these two units can work independently, and there will be some kind of communication happening between them.

In this chapter, we will discuss how we can communicate with an embedded controller board from a computer running on ROS. It is very...