A1. Basic Movements: Simple Figure

Objetive

Computer skills worked on

Additional information

The robot must describe a trajectory that draws a simple geometric figure assigned to the group.

Abstraction, algorithmic thinking, and debugging.

Figures to be created by each work group:

·         Group 1: Square with a side length of 40 cm.

·         Group 2: Equilateral triangle with a side length of 40 cm.

·         Group 3: Rectangle with a long side of 40 cm and a short side of 20 cm.

·         Group 4: Pentagon with a side length of 30 cm.

·         Group 5: Hexagon with a side length of 25 cm.

Solution

In Figure 2, an example of a solution is shown, which works for any of the requested regular figures (square, triangle, pentagon, and hexagon), as well as for any regular figure that is to be created. One only needs to specify the number of sides (4 in the example) and the length of each side (40 in the example). In Figure 3, an example of a solution for drawing the rectangle is shown. These solutions are general, allowing for easy modification of the result, but students typically use the simpler method of indicating repetitions and values directly in the instructions.

Figure 2. Basic Movements: Simple Figure. Solution for regular figures.

Figure 3. Basic Movements: Simple Figure. Solution for the rectangle activity.

A2. Advanced Movements: Complex Figure

Objetive

Computer skills worked on

Additional information

The robot must describe a trajectory that draws a single-stroke figure assigned to the group.

Abstraction, algorithmic thinking, and debugging.

Figures to be created by each work group. Figure 4 presents the assignment of more complex geometric figures to each work group with the goal of working on more advanced movements.

Solution

For this exercise, it is ideal for students to plan the movements on paper first and then transfer them to the program. They should first think about the solution to the problem and then figure out how to implement it in the program.

Figure 4. Geometric Figures for Working on Advanced Movements with the Robot.

A3. Ultrasonic Sensor: Avoiding Obstacles

Objetive

Computer skills worked on

Additional information

The robot must avoid any obstacles it encounters in its path.

Abstraction, algorithmic thinking, decomposition, and debugging.

§  Detect at a certain distance.

§  Use the “Forever” block.

§  Choose what to do when an obstacle is detected.

Solution

Figure 5 shows an example of a solution for this activity. Typically, students make the robot turn in the same direction whenever an obstacle is encountered. Once this is achieved, they can be asked to make the robot turn randomly to either side, with a different turning angle each time.

Figure 5 – Solution to Activity 3: Avoiding Obstacles.

A4. LEDs: “Kit” Light (Knight Rider Car)

Objetive

Computer skills worked on

Additional information

It must display the back-and-forth movement of lights like the Knight Rider car, similar to the one shown in Figure 6.

Figure 6. Image of the Knight Rider car lights.
Fuente: qkbestet.pics

Abstraction, algorithmic thinking, automation, and decomposition.  

Figures to be created by each work group:

·         Use the “LED” instruction block.

·         Start with the movement of a single LED, aiming for a smooth motion.

Solution

Figure 7 shows a simple solution, for example, moving 2 LEDs without leaving a trail. Typically, students begin by initializing the light to display each time (the first one that appears in the figure after pressing button B) in a different position. This solution is not very effective, so the next step is to ask them to create a code that can be easily modified to be valid for any length of the LED strip, not just the 5-LED strip shown. An additional improvement for more advanced students would be to try doing it while viewing the trail.

Figure 7 – Solution to Activity 4: Kit Light.

A5. RGB Sensor: Line Following

Objetive

Computer skills worked on

Additional information

The robot must find the black line and continuously follow it along the entire path.

Abstraction, algorithmic thinking, decomposition, debugging, automation, and generalization.

There are 4 sensors in the mBot2, as shown in Figure 8. The L1 and R1 sensors must be used.

Figure 8. RGB Sensors of the mBot2.

Use the “Forever” block. 

Use “detect line” in the instructions instead of detecting a specific color. 

Pay attention to the motor rotation direction if that instruction is used. See the direction of rotation for each wheel in Figure 9.

Figure 9. Direction of Motor Rotation in the mBot2.

Use logical operations according to the 4 detection states of the 2 sensors with the line, as indicated in Figure 10.

Figure 10. Logical Operations of the 4 States. Source: Author’s own creation.

Solution

Figure 11 shows a simple solution for this activity. Typically, students start by making small 1° turns for the curves and then check again. This causes the robot to spin in place, giving no sense of forward motion in the curves. Once this is achieved, they can be asked to make the curves smoother, allowing the robot to maintain its sense of forward progress. Finally, they could do it at a higher speed and perform some action upon detecting a color on the line.

Figure 11 – Solution to Activity 5: Line Following.