LEGO MINDSTORMS EV3

This tutorial is about how to follow a wall with an ultrasonic sensor. The example is with a border from a FIRST LEGO League (FLL) competition, but could also easily be applied to other competitions and problems.

Now we have to program the robot. The steps that we will cover are starting the software, writing a program and downloading it to the robot.

How should an instructor use this course when working with students and a group of students in school

The balance of the construction of the robot has a great influence on how it will move. This is especially true if you would like to move in a straight line. If the robot is slightly heavier on the right it will move to the right. Here we have two robots - a Five Minute robot and a Box Robot and we will discuss the differences in the constructions and why the box robot is much better than the Five Minute even though it is using the same parts. 

The gyro sensor indicates the angle of the turn the robot made. We certainly can use this to create a robot that could perfectly follow a direction, right? Now we'll show you the easiest way to do it.

The first task today shows students how motors generate power. If students are older, you can give them more information about electricity and current. In the general case, however, it is enough to say that the faster the motor rotates, the more power it generates. This can be seen from the current power option of the wait and switch blocks. You can show students this option or leave them search for it in lesson 1.

The next task is to download a block and insert it in a program. This block reads the power from port A and transmits it to port D. The aim of the exercise is to highlight the difference between wheels. As T-Rex has larger wheels, it moves faster.

The following two tasks show that even when the wheels of the robot are larger, a lot of power is lost when the two motors are connected directly. You can explain that this is the principle due to which an eternal engine cannot be built.