This tutorial covers how to use Simulink to program a Zumo Robot powered by an Arduino Uno to follow a line using the reflectance sensors present at the bottom of the Zumo Robot. This guide will explain how the data from the reflectance sensors can be used to control the Zumo Robot motors using a control logic known as PID control.

The specific steps to get there are

1. Install Simulink Support package for Arduino
2. Download the Zumo Robot Library in Simulink
   
3. Create a Simulink Model of a PID Controller for the Zumo Robot
   
4. Build and download the model to see the robot in action
   

This guide is the third tutorial in a series on using Arduino with Simulink. For a quick introduction to Simulink and Arduino, refer to the Set up and Blink - Simulink and Arduino Tutorial. This tutorial builds on the concepts discussed in the previous tutorial titled How to program a Zumo Robot with Simulink and adds to the model described in that section. It is highly recommended that you check the previous tutorials before trying this one, if you are new to Simulink.

Even though this tutorial uses the Zumo robot, you can use the concepts discussed here to program any line following robot using Simulink.