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Teacher Toolbox icon Teacher Toolbox - Facilitating the Rethink Challenge

In this Rethink challenge, groups will add to their 'Lab 8- Sort Colors' VEXcode V5 project to sort one red, one green, and one blue disk into their drop off locations.

What the Teacher Will Do:

  • As a whole class, introduce the challenge to students. Explain that they will be adding to their projects to code the Workcell to pick up three disks and sort them by color based on the Optical Sensor. This is an extension of the project they created in Play.
  • Break students into their groups. Ensure they have their assigned Workcell, their device with VEXcode V5, and their engineering notebooks.
  • Instruct groups to follow the steps on this page to complete the challenge.
  • While groups are completing the challenge, circle the room.
    • Ask students about how the challenge is going. How are they determining the x, y, and z-coordinates for the green drop off location?
    • How are groups finding the z-coordinate with three disks in the pick up location?
    • For groups that are struggling, encourage them to look back at the Play section for specific steps on how to build the project and find locations.
  • After groups have completed the challenge, bring students back together for a whole-class discussion. Ask students some of these questions to wrap up the challenge.
    • How did your group determine the x, y, and z-coordinates for the green drop off location?
    • How did your group change the zHeight variable to account for the third disk? 
    • What did your group find difficult about this challenge?
    • Did your project work the first time you tried it? If not, what changes did you make to improve it?
    • How did your group work together to solve the challenge? What could you do to improve your collaboration in the next Lab?
  • Use the Collaboration and Programming Rubrics (Google / .docx / .pdf) to provide students with feedback and assess their projects throughout the Rethink challenge.

For more information on how to facilitate the Rethink challenge, go to the V5 Workcell Educator Certification.

In this challenge, you will create a VEXcode V5 project that instructs the arm on the Workcell to pick up three disks of different colors from the pick up location, and then drop off each disk in the matching drop off location. The color of each disk will be detected and reported by the Optical Sensor.

Rethink final

Follow these steps to complete the challenge:
  • Using the skills developed earlier in this Lab, edit your VEXcode V5 project from the Play section. The arm of the Workcell should perform the following behaviors for each of the three disks:
    • Move to the pick up location when the Brain's screen is pressed.
    • Pick up one of the three colored disks and move the disk over the Optical Sensor.
    • Based on the color reported by the Optical Sensor, move and drop off the disk in the matching color location.
  • Note that the pick up location will be filled with three disks at the beginning. Your project should account for the varying heights of the disks while in a stack.

Teacher Tips icon Teacher Tips

  • Ensure students have their mastering values readily available from the Seek section.
  • Before students begin, check that they have set the tool to ‘electromagnet.’

Set electromagnet block in vexcode

  • Remind students about using the zHeight variable to store and change the z-coordinate value of Point 2 while the project is being run.
  • In order to have the disks accurately fall into their drop off locations, the coordinates of the locations need to be precise. Have students check the (x, y, z) coordinates of the drop off locations and record the values in their engineering notebook.

Teacher Toolbox icon Teacher Toolbox

 The following is an example of one possible solution for the Rethink challenge. Because students are using the 'Lab 8- Sort Colors' project from the Play section, they should be adding an additional [If then] block for if the Optical Sensor detects 'green.' Note that these x, y, and z-coordinate values may differ, so observe each group's project to ensure it works as intended.

code snippet detecting green

Because this challenge also asks students to sort three disks, their starting value for the zheight variable should be set to the height of three disks in the pick up location.

zheight variable called out

Below is an image of the full project for reference.

full rethink sample solution code