In this course, which has Course "Build A Motion Controlled Wheeled Robot" as its prerequisite, students will learn how to equip the wheeled robot created in course "Build A Motion Controlled Wheeled Robot" with ultrasonic sensors in order to avoid obstacles along its path, much like the Mars Rovers navigate on the surface of the Red Planet. Firstly, students review the 4-wheeled Mars Rover's basic parts and are given an introduction about its sensors, followed by a more general explanation about how different sensors work, and a more detailed presentation of ultrasonic sensors. Then, they are taught how to attach the ultrasonic sensors on the 4-wheeled robot, and how to connect them to the processing board. Afterwards, the robot is connected to the programming environment and students program the basic sensing functionalities of the robot using predefined functions given in libraries in the Python programming language. Finally, the students combine the motion and sensing functions they learned to complete the navigation of the robot within a specific environment to reach a goal location while avoiding some obstacles in the way and overcoming others.