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Mars Rover-Exploring Mars Geology
Lab 2 - Study your Martian Rock Sample

Teacher Portal

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 what the Eye Sensor could be used for.
  2. Show students a Code Base - Eye + Electromagnet, or refer to the image in the Lab 2 Image Slideshow (Google Doc / .pptx / .pdf) to highlight the position of the Eye Sensor in relation to the Electromagnet. Guide students to the idea of how the Eye Sensor can detect the color of the object, such as a Disk picked up by the Electromagnet. Put a Disk on the Electromagnet and ask if the sensor can see the color.
  3. Have students share their ideas about whether or not the robot can be used to sort by color. If needed, remind them how they moved a Disk in Lab 1, and guide them to see that this is building on that action.
  4. Have students offer if/then scenarios that they encounter in their daily life at home or at school. Encourage them to phrase them as if/then statements, to reinforce this cause and effect relationship.
  5. Get students ready to build this project together with you.
  1. In the last Lab, we used the Electromagnet on our Code Base. Our robot also has an Eye Sensor on it, too! How do you think we could use the Eye Sensor with the Electromagnet to make our Code Base do more things?
  2. Look at where the Eye Sensor is on the Code Base. Why do you think it is behind the Electromagnet? Why do you think it is pointing down? What do you think the Eye Sensor can detect about the Disk that the Electromagnet has picked up?
  3. If the Eye Sensor can detect the color of something picked up by the Electromagnet, like a Disk, what could we do with that information? Could we make our Code Base sort Disks by color, like you can do with things in our classroom? Why or why not?
  4. We can use a special kind of block to have our Code Base check to see if the Eye Sensor is detecting a color, like red, then do something. What is something you do that works the same way? For example, if you saw a book on the floor, then you would do what?
  5. We can use the Eye Sensor information to have our robot make a decision - like if you see a book, then you decide to put it away. How can we code the Code Base to make a decision based on the color detected by the Eye Sensor?

Getting the Students Ready to Build

Let’s see what blocks we can use with the Eye Sensor in our VEXcode GO project, to make it sort a Disk by color. (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 show them how the Eye Sensor reports data in VEXcode GO, and how that data can be used, before they begin their projects.
    • 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.

    Code Base Eye and Electromagnet
    Code Base - Eye + Electromagnet

  3. FacilitateFacilitate a demonstration of the Eye Sensor, and using Eye Sensor data in a VEXcode GO project, for students.

    NOTE: select the 'X' icon to remove sensor data from the Monitor Console. 

    Select the 'X' icon to remove sensor data from the Monitor Console
    Select the 'X' icon to remove sensor data from the Monitor Console

    • Place a Red Disk beneath the Eye Sensor, and show students how the Monitor Console says “true,” as shown in the image above. Remove the Red Disk, and show students how the value changes to “false.” You may want to remind students that the <Detects color> will only report a value of “true” or “false,” it will not report a number, color, or other value.
    • Next, drag an [If then] block into the Workspace and attach it to the {When started} block. Show students the open space in the block, and ask them what they notice about the shape of the space, and the shape of the <Detects color> block?
      Image of the [If then] block in VEXcode GO
      [If then] block
    • Drag the <Detects color> block into the [If then] block. Have students describe what they think this block will now make the robot do. Explain that the [If then] block will check for a condition - if that condition is true, the blocks inside it will run. If the condition is false, they will not.
      Image of the [If then] block with the <Detects color> block in it
      Add <Detects color> block
    • Drag a [Drive for] block into the [If then] block. Ask students to predict what will happen if the Eye Sensor detects red. Start the project, and place the Red Disk beneath the Eye Sensor. The Code Base should move forward 100 millimeters, because the condition of detecting the color red reported true.
      Image of the [Drive for] block added to the [If then] block
      Add [Drive for] block
    • If time allows, ask students to predict what will happen if the Eye Sensor does not detect red. Start the project, placing a Blue Disk beneath the Eye Sensor. The Code Base should not move, because the condition of detecting the color red reported false.
  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. 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 Disk 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 Red Disk is shown in place for Play Part 1, with the sorting area marked. You may want to mark the starting locations of the Disk and the Code Base, as well as the sorting area location with a dry erase marker to help students when they are setting up to test their projects.
    Field Setup Image
    Field Setup
  • Use the grid lines 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. 
  • To help students see the Eye Sensor data while their project is running, they can open the Monitor Console at any time, to see when the Eye Sensor changes from true to false. What is changing on the Field when that happens?
  • If students finish early, have them test their project with a Blue or Green Disk. Does their project still work? Why or why not? What would they need to change to make the Code Base move the new Disk to the sorting area?