Hands-on Activity Mars Rover App Creation

Learning Objectives

After this activity, students should be able to:

• Design and create a mobile app for an Android device using MIT's App Inventor.
• Apply the steps of the software/system (engineering) design process.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

International Technology and Engineering Educators Association - Technology

State Standards

Materials List

Each group needs:

• LEGO MINDSTORMS EV3 robot, such as EV3 Core Set (5003400) at https://education.lego.com/en-us/products/lego-mindstorms-education-ev3-core-set/5003400#lego-mindstorms-education-ev3
• Android device, such as a smartphone or tablet (Look at the http://appinventor.mit.edu/explore/ website for a list of all devices known to work with App Inventor; see the right column under the "Phones & Tablets Database" title.) Note: It is best if each group has an Android mobile device. If not enough are available, adjust the group sizes to match the number of devices. Or, if the class is small enough, work together as one group, sharing a teacher-provided Android mobile device. Realize that these options may limit the learning experience of each student.
• Google Gmail account
• App Inventor online registration at http://appinventor.mit.edu/explore/learn.html
• computer with internet access
• App Inventor General Information
• Mars Rover App Rubric
• Technological Design Process Worksheet

Alternative: LEGO MINDSTORMS NXT Set:

Note: This activity can also be conducted with the older (and no longer sold) LEGO MINDSTORMS NXT set instead of EV3; see below for those supplies:

• LEGO MINDSTORMS NXT 2.0 

Worksheets and Attachments

Pre-Req Knowledge

This activity is recommended for use in a computer programming class or environment. Students should have a basic understanding of computer programming design and control structure. Students also need a basic knowledge of how MIT's App Inventor works. Prior to this activity, students should have worked through the MIT App Inventor tutorials, available online at http://appinventor.mit.edu/explore/learn.html, to gain an understanding of how App Inventor works. The Program Analysis Using App Inventor lesson and its associated Flow Charting App Inventor Tutorials activity provide students with experience with both the engineering design process and App Inventor, and should be completed prior to this activity. In addition, App Inventor General Information provides general App Inventor concepts and may be useful as a reference for the teacher and students during the activity.

Introduction/Motivation

In today's activity, you will develop an app for an Android device. However, the activity is about more than the single app you will develop. It is about the skills that you gain while you interact with a piece of software that helps you develop your app.

As a reminder from the associated lesson: Algorithmic Remote Rover Programming: Curiosity Killed the App, the software design process closely resembles the engineering design process.

At the end of the activity, you should have the skills in place to write other apps for Android devices. If you desire, you could even apply the skills that you learn in this activity to your Android device so that you can write other Android apps that could be published for public use.

Procedure

Background

Students develop apps for Android devices that can control some aspect of a LEGO MINDSTORMS EV3 robot simulating the Mars Curiosity rover. This might be driving the robot, moving an arm, detecting objects, applying a game or using a sensor such as the color sensor.

Refer to the Lander Student, Mars Project Student and Shooter Student as example apps created by students that can be loaded on Android devices for teacher and students' reference.

This activity provides students with experience in the software/systems design process and gives students experience with the software application App Inventor. Using App Inventor, people can write software applications that execute on Android devices.

Before the Activity

• Install and set up the App Inventor software. For instructions on how to do this, see the tutorial on the MIT website: https://appinventor.mit.edu/explore/ai2/windows.html.
• The teacher and students should have a basic working knowledge of programming and how App Inventor works. As necessary, use App Inventor tutorials at http://appinventor.mit.edu/explore/.
• Divide the class into groups of three students each (assuming enough robots and Android devices).
• Make copies of the App Inventor General Information, Mars Rover App Rubric, and Technological Design Process Worksheet, one per group.

With the Students

1. Explain the activity goal to the class. Student groups are responsible for creating a mobile app, using App Inventor, which completes a (simulated) Mars remote sensing task. These tasks might include driving and moving the robot, moving an arm, detecting objects, applying a game, or using a sensor, such as the color sensor.
2. Hand out the general information sheets, rubrics and worksheets.

   

3. Introduce the criteria for a successful app design. The app must:

• Have a Mars (or other planet) scientific connection. Example: The app may be designed to help the rover steer around or climb obstacles found in rough surface conditions. The app may have the robot measure humidity or temperature in the planet's atmosphere.
• Use at least five App Inventor tools/objects. Examples: Canvas, alignment, button, text box, sprite, label, list picker. See Figure 1 for a full list. Note: These are examples of major objects in App Inventor that app commands are built around. The canvas serves at the background; colors, gradients or landscapes can be placed here. Alignments are a quick way to implement spacers with the app code. Buttons are action buttons; each button must be coded to the specific action assigned to the button. Text boxes are where text appears. Sprites are animated objects and are holders for the eventual code that specifies their actions and use. Labels are simply names for objects. List picker is a shortcut to building pull-down menus into the app. Clarify to the students that each object must be renamed, such that the name fits the purpose. In addition, each object must have a purpose. The object cannot just exist, but must have a stated purpose or action attached to it. Finally, each object must be edited in some way. The object cannot be set at the default setting.
• Have a background image. This could be a stand-alone image or part of the canvas, button or other object. This counts as one of the five required objects.
• Have a button with some function. This counts as one of the five required objects.
• Have an animated object. This could either be an image or a ball that moves in the program. This counts as one of the five required objects.
• Have a reset option that can be used over again without restarting the app.

4. Let students know the expected deliverables for the activity. The final app design must be debugged and work correctly. Their finished worksheets must be handed in.
5. Have each student group brainstorm a list of problems to be solved with Mars exploration.
6. After specific problems have been selected, direct student teams to follow the software/systems design process steps as they develop Android apps using App Inventor that solve their Mars exploration problems. The design process consists of five steps: problem analysis, creating a design, implementation of the design, testing the design and evolution of the design. Groups must complete at least one full cycle of the design process.
7. During the design process, have students use and complete the worksheet to organize the process (and to be handed in). Remind them to use the rubric as a guide throughout the design process.
8. Conduct the testing using a LEGO MINDSTORMS EV3 robot. To run a test, each group loads the app on an Android device using App inventor and then attempts to control the robot using the app.
9. To conclude the activity, have each group present their app to the class to show how it controls the robot. Depending on the time available, this can serve as the testing phase of the design process or can be done after each group has already had time to test and revise their applications.

Vocabulary/Definitions

Android device: A mobile device with the Android operating system installed on it.

App Inventor: Software program developed by MIT that enables Android apps to be created using building blocks without having to actually know a programming language.

design: A step in the software design process involving brainstorming to create possible solutions to the problem.

evolution: A step in the software design process in which the design is further explored to see if it can be made more efficient, improved on, or applied in other situations.

implementation: A step in the software design process in which a design is put into practice.

requirement analysis: A step in the software design process in which the problem is defined and parameters that frame the problem are established.

testing: A step in the software design process in which a design is tested to see if it solves the identified problem as intended.

Assessment

Pre-Activity Assessment

Design Process: Review the steps of the software/system design process with students. Ask them to list the steps and how they can be applied to this type of activity. (Teacher notes: The design process consists of five steps: problem analysis, creating a design, implementation of the design, testing the design and evolution of the design. Students should explain how to complete at least one cycle of the design process. Remind students that the design process is circular and is never fully completed, as designs can always be improved.)

Activity Embedded Assessment

Observations: As students are engaged in their application design, observe them and take notes that address the following questions:

• Are students consciously following the design process steps?
• Have they chosen one problem to solve?
• Do they understand the problem they chose to solve?
• Were they able to devise a plan to solve the problem?
• Did they carry out their planned design?
• Were students able to use App Inventor to solve the problem?

Post-Activity Assessment

App Evaluation: Assess and grade each group's app design and completed Technological Design Process Worksheet by using the Mars Rover App Rubric. The rubric provides guidance on how to grade the app design based on its science content, elements, process, function and creativity.

Activity Extensions

Have students create a second app that addresses another problem that the Curiosity rover might encounter. This app should have the same requirements and can be assessed and graded with the same rubric.

Copyright

Contributors

Supporting Program

Acknowledgements

The contents of this digital library curriculum were developed as a part of the RET in Engineering and Computer Science Site on Infusing Mobile Platform Applied Research into Teaching (IMPART) Program at the University of Nebraska-Omaha under National Science Foundation RET grant number CNS 1201136. However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government.