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Mars Rover-Exploring Mars Geology
Lab 3 - Sort your Samples

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Launch the Engage Section

ACTS is what the teacher will do and ASKS is how the teacher will facilitate.

  1. Have students share their ideas about how this could be used by the real Mars rover. Remind them of the things the real rovers, like Perseverance, are looking for. You can use the Background information as a reference.
  2. Encourage students to think about the surface of Mars, and the samples that could be collected - this can be general, like “rock” or “soil.” The idea is to show that there is a need for sorting different items using sensor data.
  3. Guide students to the idea that since there are no humans on Mars to do this work, so the Mars rovers, like Perseverance, have to keep things organized for future study.
  4. Have students share their answers, and draw on their experiences with the Code Base in the previous Lab to guide them to the idea of using a condition, or an [If then] block, like they did in Lab 2.
  5. Get students ready to explore this with you.
  1. In Lab 2, we used our Code Base to sort a Disk based on its color. Why do you think this kind of behavior could be useful on the Mars rover?
  2. We used Disks to represent rock samples – do you think there is more than one kind of rock sample to sort on Mars? What kinds of samples do you think the Mars rovers, like Perseverance, are collecting?
  3. Why do you think it’s important for the rover to be able to sort the samples after they’re collected?
  4. How do you think scientists code the rover to collect and sort different types of samples to different places? How can they use the sensor data from the rover to help it make decisions about how to sort the samples?
  5. Let’s think about what we did in Lab 2 - we used a Red Disk to represent a rock sample. What if we added a Blue Disk or a Green Disk to represent other types of samples? How can we code our Code Base to collect and sort multiple Disks based on their color?

Getting the Students Ready to Build

Before we build our projects, let’s look a little more closely at how they are working, when the Code Base is making a decision. (If students do not have a pre-built Code Base - Eye + Electromagnet from the previous Lab, allow 10 - 15 minutes for students to build it prior to the Lab activities.)

Facilitate the Build

  1. InstructInstruct students that you are first going to look at their project from Lab 2 using the Stepping feature in VEXcode GO, to see the project flow more clearly.
    • When students join their groups, have them complete the Robotics Roles & Routines sheet. Use the Suggested Role Responsibilities slide in the Lab 1 Image Slideshow as a guide for students to complete this sheet.
  2. DistributeDistribute one pre-built Code Base - Eye + Electromagnet, a Red Disk, and a tablet or computer with VEXcode GO open for demonstration purposes. Students should be able to see the screen and the robot. Students will collect their materials after the demonstration.

    Image of the Code Base - Eye + Electromagnet build
    Code Base - Eye + Electromagnet

  3. FacilitateFacilitate a demonstration of stepping through a project for students, to show the project flow with the [If then] block.
    • Continue to step through the project, to show students how the highlighting moves through the blocks in the [If then] block as the Code Base sorts the Red Disk. 
    • Once you have stepped through the project completely, remind students that the Mars rover will collect different kinds of samples. Show students the Blue Disk, to represent a different rock sample. Reset your Code Base on the Field and replace the Red Disk with a Blue Disk. 
    • Step through the project again, and after collecting the Blue Disk, ask students to predict whether the blocks inside of the [If then] block will be highlighted: 
      • If we use a Blue Disk instead of a Red Disk, will the blocks inside of the [If then] block be highlighted? Why or why not? 
        • Since the Disk is blue, and <Detects color> block is set to 'red', the condition of the [If then] block is false. So the blocks inside of the [If then] 'C' block will NOT run. 
    • Ask students what they could do to code their Code Base to make it sort both Red and Blue disks. Tell students that they will be exploring this during Play, when they build on their projects to add more [If then] blocks, to make their Code Base collect and sort different colored Disks to their sorting areas, based on color. 
  4. OfferOffer positive reinforcement for students who are actively engaging in the demonstration, asking and answering questions, and listening to their classmates.
A VEX GO character

Teacher Troubleshooting

Facilitation Strategies

  • Think about how your students will access VEXcode GO. Ensure that the computers or tablets that students will use have access to VEXcode GO. For more information about setting up VEXcode GO, see this VEX Library article.
  • Gather the materials each group needs before class. For this Lab, each group of two students will need a GO Kit, Build instructions, a computer or tablet to access VEXcode GO, and the Red, Blue, and Green Disks from the Kit. Students will also need access to a Field for testing. 
  • Set up your Fields ahead of time, as shown in the image below, to serve as a testing area for the Code Base. Have these spread out around the classroom to allow students ample space to test their projects. In this image, the Blue Disk is shown in place for Play Part 1. You may want to mark the starting locations of the Disk and the Code Base, as well as the sorting area locations with a dry erase marker to help students when they are setting up to test their projects.
    Image of the Field setup with sorting areas marked
    Field setup
  • Use the gridlines on the Field to help with alignment. The Disk and the Electromagnet can both be lined up on intersecting grid lines of the Field, to make it easier for students to be set up for success when they test their projects.
  • Students can use the Step button at any time while testing. The Step button can be used during student tests, to help them slow down their project’s execution, and more easily identify mistakes while troubleshooting. Students can look at each block’s behavior individually, to better identify where the robot is not performing as intended. 
  • If students finish early, have them test their project with the Red Disk. Does it collect and sort the Red Disk to the correct sorting area? Why?