What the Teacher Will Do:

• Instruct students that they will continue to work in their groups to follow the steps on this page.
• Circle the classroom as students work through the steps on this page and answer any questions that arise.
• Students will let you know when they are ready for their check in. Guidance for this check in is provided in a Teacher Toolbox at the bottom of this page.
• Once all groups have finished testing their projects, bring the groups together for a whole-class discussion. Guidance for this discussion is provided in a Teacher Toolbox at the bottom of this page.

If groups are finding that the arm does not pick up and move the green disk when they run their project, try the following troubleshooting techniques.

1. Check the VEXcode V5 project.
   1. Compare the code provided here to the group's project and ensure the order of the blocks match. Make sure students are re-downloading their project each time they make a change and before they run the project.
      
   2. Check the x, y, z-coordinate locations for the pick up and drop off locations of the green disk. They may need to be edited. Encourage students to use their knowledge of the x, y, and z-coordinate system on the Workcell to determine how to make small adjustments to the coordinate values in the project.
2. Check the mastering values.
   1. Instruct students to check that the mastering values they recorded in their engineering notebook during Seek match what is in the [Set mastering] block.
   2. If the problem still persists, have students follow the steps in Seek to rerecord their mastering values.
3. Check the build. 
   1. There may be a mechanical issue with your Workcell. Instruct students to look at the Lab 10 build instructions first and verify that the additions to their Workcell match.

Review the following with groups during their check in:

• Ensure groups have built their project correctly based on the images on this page. Note that the mastering values will vary depending on the group and the coordinate values may vary between groups.
• Ensure that the green disk moves onto the transport conveyor, the diverter spins to the 0 degree position, the disk moves along the transport conveyor and stops at the pickup sensor. Have students show you their project. If the project does not work as intended, see the Teacher Toolbox - Troubleshooting section above.

After groups have finished testing the project and moved the green disk from the entry conveyor to its designated drop off location, engage the class in a discussion about their experience and observations using conveyors and sensors together on the Workcell system.

• Begin by asking groups to share their projects with one another. If time allows, have groups run their project for the class.
• Then ask groups to share any observations they had while creating and testing the project. Ask students questions such as:
  • How did your project use the Optical Sensor? Students should explain that the Optical Sensor was used in the project to trigger certain behaviors depending on if a colored disk was present. Explain to students that even when the project is running, none of the conveyors or the diverter spins until a disk is detected by the Optical Sensor. Certain behaviors of the conveyors and the diverter are triggered depending on the color of the disk detected.
    • For the red disk, students should note that the diverter is engaged (set to the 90 degree position), the exit conveyor spins, and the exit sensor is used. 
    • For the green disk, students should note that the diverter is not engaged (set to the 0 degree position), the transport conveyor continues to spin, the exit conveyor does not spin, and the pickup sensor is used. 
  • What was the purpose of the Line Trackers in this project? Students should explain that the Line Trackers in this project were used to trigger different behaviors of the conveyors and the diverter.
    • The load sensor indicates that the disk was successfully loaded onto the transport conveyor and also spun the diverter to the appropriate position depending on the color of the disk.
    • The exit sensor indicates that the disk was diverted off successfully and was used to trigger the behavior of stopping the conveyors from spinning.
    • The pickup sensor indicates that the disk passed through the diverter successfully and was used to trigger the behavior of stopping the transport conveyor from spinning as well as engaging the arm's movement.
  • How did your group use My Blocks in this project? Students should explain that My Blocks were used in the project to better organize the code and the overall flow of the project. Explain to students that if the My Blocks were removed and all of the blocks in each of the red, green, and blue stacks were put into the [If then else] blocks, the project would have been a lot longer and not as organized. Using My Blocks also allows for the same behaviors to be repeated.