Here is How To Build A Line Follower Arduino Robot - Tutorial45

Arduino Line Follower Robot

Arduino Line Follower With PID and 90 Degree Turns

How do I start and stop a loop with the press of a button. (Arduino IDE for Arduino Uno)

Arduino Timer Interrupts

6 Methods to Stop an Arduino Program - NerdyTechy

19 Awesome Robots You Can Build With an Arduino | Random Nerd Tutorials

Build an Arduino Robot | Science Project