Programming Turning Right and Left - Blocks-based

• This exploration will introduce students to basic turning right, left, and waiting programming behaviors.

• Using the drivetrain robot configuration enables the students to program the Speedbot to turn by just selecting the [Turn for] block.

If this is the student’s first time using VEXcode V5, they can reference the Tutorials at any time during this exploration. The Tutorials are located in the toolbar.

• Model each of the steps for checking that the Speedbot is ready so that students will get into the habit of doing so.

Point out that when they first opened VEXcode V5, the window was labeled VEXcode Project and it was not saved (indicated on the toolbar). VEXcode Project is the default project name when VEXcode V5 is first opened. Once the project is renamed Turn and saved, the display updates to Saved. Using this window in the toolbar, it is easy to check that the students are using the correct project and it is saved. Once a project is initially saved, VEXcode V5 autosaves any subsequent changes, as indicated by the message next to the project name.

Tell the students that they are now ready to begin their first project. Explain to the students that by following a few simple steps, they will be able to create and run a project that will turn the Speedbot.

• Since this is a beginning activity with programming, the teacher should model the steps, and then ask the students to complete the same actions. The teacher should then monitor the students to ensure that they are following the steps correctly.

• Make sure that the students have selected Open Examples from the File menu.

• Make sure that the students have selected the Speedbot (Drivetrain 2-motors, No Gyro) template project.

  You can point out to the students that there are several selections to pick from on the Examples page. As they build and use other robots, they will have a chance to use different templates.

• You can ask students to add their initials or the name of their group to the project name. This will help differentiate the projects if you ask the students to submit them.

• Point out that in the programming area, there is already a {When started} block located there by default. Every project will begin with this block. When the project is started the connected blocks will be followed in the sequence in which they are placed.

  Demonstrate clicking on the [Turn for] block and dragging it to the programming area, connecting it to the {When started} block. You will hear a click when as it attaches.

• If you are using a computer, the student should have VEX V5 Robot Brain connected to the computer using a USB cable. If you are using a tablet, the VEX V5 Robot Brain should be connected to the tablet using the Smart Radio.

• If the students are using a computer, ask them now to disconnect the USB cable from the Robot Brain. Having the robot connected to a computer while running a project could cause the robot to pull on the connection cable.

This is a good point to pause and have the student reflect on running their first project. As students:

• What did Speedbot do when you ran the project?

• Did it behave as you would expect it to, based on the project?

Take a moment to make sure all students have completed this step without any issues before moving on.

Model running the project in front of the class before having all the students try at once. Gather the students in one area and leave enough room for the Speedbot to move if it is placed on the floor. Since the Speedbot will continue running the project until the back button on the Robot Brain is pressed, the teacher may want to choose someone to assist in stopping the Speedbot's project when it finishes.

Tell the students it is now their turn to run their project. Make sure that they have a clear path and that no Speedbots will run into each other.

• To change the [Turn for] block from right to left, simply click on the dropdown menu and select left.

• If the students are using a computer, remind them to disconnect the USB cable from Robot Brain before running the project.

  Because we are not selecting a new slot, the new project will download to slot 1 and replace the previous project.

• Since VEXcode V5 has autosave, there is no need to save the project again.

• A [Wait] block can be placed anywhere in the project. For more information on the [Wait] block, open the Help.

• Using a [Wait] block will not end the project.

• If the students are using a computer, remind them to disconnect the USB cable from Robot Brain before running the project.

• Since VEXcode V5 has autosave, there is no need to save the project again.

Q: Viewing the robot's current position at zero degrees, If the robot turned left 90 degrees, then turned right 120 degrees, and finished by turning left 40 degrees, how many degrees would the robot currently be at after it finished turning?
A: The robot will be at 10 degrees. After turning left 90 degrees, the robot turned right 120 degrees. Viewing turning left as moving in a positive direction and turning right as subtracting or moving in a negative direction - similar to an x-y coordinate plane, this now puts the robot at -30 degrees. Since 90-120 = -30. From -30 degrees, the robot turns left 40 degrees. Thus, -30 + 40 = 10. The robot ends at 10 degrees.

Q: Viewing the robot's current position at zero degrees, turning the robot 30 degrees to the right will have the robot finish in the same spot as starting from zero degrees and turning the robot 330 degrees to the left. If the robot turned right 56 degrees and, how many degrees to the left will the robot have to turn to end in the same place assuming it starts from zero degrees?
A: Since turning the robot around fully is 360 degrees, you can add and subtract from 360 degrees to calculate how the robot will need to turn. 360 - 56 = 304. Thus, the robot will have to turn 304 degrees to the left to end in the same place as turning 56 degrees to the right.

- View the sample solution below.

- A programming rubric to evaluate students can be found here (Google / .docx / .pdf ).

For a more advanced solution, a student can also be introduced to loops by using the [Repeat] block. For more information about the [Repeat] block, view the Help.

Validate that the robot successfully completed the challenge by watching the robot's starting position, and count to ensure that the robot has performed the correct actions. The robot should turn right for 90 degrees, then repeat three times: a turn left for 180 degrees and a turn right for 180 degrees.