Video tutorials -

• FIRST LEGO League

Every time we start the robot we want to start from the same place, not only in terms of where we are on the field but also in terms of how are the motors rotate. The motors have an internal sensor for detecting the rotation. Because of this they know how rotated they are. It is a very good practice to always reset the motors before we start a competition run especially at FIRST LEGO League or World Robot Olympiad competitions

In this video tutorial we take a next step in programming reliable and consistent robots and this is to learn how to stop at a second intersection. We need this because most of the time when we want to reach a mission model on a robotics competition field, the model will be located away from us and we must use all kind of technique to reach it. In this tutorial - we stop at a second intersection.

In this video tutorial we demonstrate a really important concept for FIRST LEGO League competitions - you position the robot on the field with depending on timers and rotations. The issue with moving the robot for 10 seconds and then stopping is that every time it is in a different location. Same for rotations. The wheels will slip, the battery will change, something will happen and the robot will not be in the same place every time. This is not consistent and reliable.

In this video tutorial we show how you can build robots that position on the field consistently and reliably by following and line and then aligning to a line. We also demonstrate the concept of "double align" which is quite powerful and even if there were some mistakes they will be handled.

Using everything that we've learned about LEGO Education SPIKE Prime competition programming we arrive at the final boss mission - how do we consistently reach a mission model at the other end of the field. Consistently. Every time. We use line following, motion sensor, counting of lines and border alignment. All the different concepts that we've looked at separately are now implemented together.

This is one of the last tutorials in the LEGO Education SPIKE Prime programming for Competitions course and it demonstrates what we've all been waiting for - how to reach a mission model from base in a reliable and consistent way when the mission model is on the other end of the field. Naturally what we use are all the different concepts that we've learned in the course and the tutorial is more advanced than the other so if anything is not clear take a look also at the different tutorials an concepts in the course.

Programming the LEGO MINDSTORMS Robot Inventor for FIRST LEGO League competitions involves learning how to turn left and right with the robot. There are not precise turns. The robot will make mistakes, because that's what robots do. But nevertheless it is important to learn how to program the robot to turn. We are releasing an additional course that is focused only on programming and how to make the robot consistent in its behavior, but in this tutorial we stop on turning

With this video tutorial we start the course for LEGO MINDSTORMS Robot Inventor and how to successfully program the robot for FIRST LEGO League robotics competition. It is good to have SPIKE Prime or EV3 for the competition. But if you happen to have Robot Inventor, don't be discourage. It is still possible to participate and accomplish a lot with the set.

Football with robots could be quite fun. Football with LEGO Mindstorms robots is one of the popular categories for competitions with LEGO Mindstorms Robots. 

We should multiply the error by a certain number and then add it to the steering of the LEGO Mindstorms Steering block. In this way, by changing the coefficient we change how much/fast should the proportional part influence the steering of the robot. 

Let's record the values of the Gyro Sensor while the robot is moving and is trying to keep its orientation straight. This is an interesting experiment and we will have to use file access to write the values to a file. 

This video tutorial contains the final 2 programs for moving straight with a LEGO Mindstorms EV3 robot. The first program is for proportional compensation that just keeps the robot orientation straight, while the second program is for Integral compensation that returns the robot to the straight line when the robot makes a mistake. 

In this video tutorial, we would do a few experiments with the coefficients for the Integral compensation. There are actually two coefficients - "c" and "b"

This video tutorial is about understanding the "magic". In this video tutorial, we would conduct an experiment and will look at how exactly does the integral part of the PID algorithm compensate for the error that the LEGO Mindstorms EV3 robot makes. 

The integral part "remembers" the errors that the robot has made in the past and we can compensate for those errors. This will make the robot return back to the line that we would like to keep it aligned. 

This is where the confusion really comes. We are keeping the robot orientation straight while the robot moves, but at the end the, robot is not at the fiinal location that we would like it to be. The robot is still about 2-3 centimeters away after moving for about a meter.

We keep the robot orientation straight while moving, but when we stop the robot could be in a different orientation. This applies for both using the Mindstorms Gyro Sensor when moving straight or the Mindstorms Color sensor when following a line. In this video tutorial, we will do a few examples of when an how this could happen.

The first part of making the robot move straight is to keep it oriented straight. While it moves it could make an error and turn slightly to the right and then the program should turn in back to the left to make its orientation straight. In this video tutorial, we would discuss how to implement a program to keep the robot orientation straight even when we are pushing or pulling it to either side and in the same time it has different wheels.

The LEGO Mindstorms EV3 set comes with two LARGE motors. But even though these motors look almost the same they are not quite the same. There are always some differences in their behaviour. If you have more than two motors, because you bought them or you won them somewhere at a competition, it is worth doing an experiment to find which pair of motors works best. 

The robot can move with different speed by applying different power to the motors. It will most of the time make smaller deviations when it moves slower. But you can't just move with a power of 10 all the time. This is a way too slow especially for competitions like FIRST LEGO League or World Robot Olympiad. In this video tutorial I would like to discuss the balance between motor power and robot movement error, how does the battery influence the power of the robot and to conduct an EV3-G experiment that will record the values of the Gyro Sensor along with the current power. 

Following the Advanced Sensor Calibration course section, it is time to extract the logic for getting a calibrated value into a new block. This block will have an input and on this input, we give the port number. The block will return the calibrated value for this port number. We've built all the other blocks only because of this almost final video here.

One of the smartest things you could do in any software program is to extract logic in small reusable, simple, understandable units. In EV3-G these are called Blocks and we are going to extract the logic for finding a minimum and maximum for each of the sensors in a new block.

In this tutorial, we show you how to display all the values from an EV3-G array on the EV3 brick display. We are using an array Read Operation along with a loop. We are also detecting the loop counter and using it as an index to an array. It's basically the only viable way to do it. The process is commonly referred to as - "Iteration over an array" (although we still do not have an iterator in the programming language, we promise that one day we would do the super advance videos on "iteration" using the LEGO MINDSTORMS robots")  

A common question is how to display arrays on the LEGO Mindstorms EV3 brick screen. Displaying values from an array is not different from any other display operation. In this tutorial, we would look at displaying two specific values. The minimum and the maximum for a specific sensor from the Advance Calibration Course Section

Following the Advance Light/Color sensors calibration for a minimum value for a single sensor tutorial, in this one, we continue with finding the maximum value detected by a sensor and storing this value in an array.

Implement a program for stopping at a black line with the blocks containing the implementation details for the InitArray, Calibration and Getting the calibrated result. 

Following the previous tutorials from the course, implement the calibration of the minimum and maximum values.