STEM Coding Max

Model 5: Tabletholder

Secured valuables

Grade
5-7
Time required
2 Double lessons
Difficulty level
Model: medium, Programming: medium
Model type
Stationary device as a support for pictures, book or smart devices with optical alarm function when approached, and optical and acoustic alarm function when the placed object is removed.
Download didactic material

MODEL DESCRIPTION / TASK

The students plan and realize a holder for presenting flat objects (pictures, books, smart devices, etc.). The displayed items are secured. A proximity sensor for "pre-alarm" (LED blinking) indicates insufficient distance from the viewer. Removing the presented objects triggers an alarm through both optical and additional acoustic signals. For differentiation, a magnetic switch can be integrated as the main switch.

EVERYDAY RELEVANCE

The protection and securing of objects is familiar to students. Security systems like a Kensington lock, a mobile phone lock in a retail display, a bicycle or ski repair kit near bike paths/slopes, etc., can be shown either in their original form or as pictures. Securing mechanical items presents a particular challenge in this context.

Key questions

  • How can a flat object be positioned so that its surface is well-visible and presented without obstruction? (Communication)
  • Where and how are important items showcased, and what are the respective advantages and disadvantages? (Collaboration, critical thinking)
  • What types of alarm signals are suitable, and how can corresponding physical properties be created if necessary? (Critical thinking)
  • What aspects of the design need to be considered to ensure the system has a secure base and the items are not at risk of falling or being damaged?


Subject relevance
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Informatics
Basics of programming, switches, sensors, time loops
Economics
Sales strategies
Technology
stable building, construction technology
Physics
Capturing physical quantities (shape, movement)

Lesson progression
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Introduction phase

Classroom Discussion (without App)

  • Query scenarios and everyday applications regarding how objects that need to be secured are presented.
  • Collect security options and preventive warning methods, and discuss their advantages and disadvantages.
  • Gather and discuss possible alarm output methods.
  • Compile desirable features related to alarm triggers (time delays, safety shutdown, deactivation function after triggering the system, etc.).

Provide assistance as needed:

  • Show sensors, actuators, and components from the construction kit; use presentation media if necessary.
Planning phase

Classroom Discussion (without App)

  • Announce the topic.
  • Identify the sensors and actuators used in the project.
  • Discuss the operating principles of the sensors and actuators used.
  • The teacher outlines the procedure using the steps provided in the app.

Partner or Individual Work (with App)

  • Students familiarize themselves with the app and download the corresponding task.
  • Students sort important and less important features of an automatic security system.
  • Students create the requirement list for the system to be built.

Optional Partner or Group Work (without App)

  • Students sketch a possible system.
  • Students discuss the results and agree on a design.
Construction phase

Partner or Group Work (with App)

  • Students use the app to build the automatic security system. The app guides them step-by-step through the building instructions.
Programming phase

Partner or Group Work (with App)

  • Students write the program for the automatic security system. The app guides them step-by-step through the programming process, and assistance is available within the app.
  • The program is transferred to the RX controller.
Experimentation and test phase

Partner or Group Work (with App)

  • The security system is put into operation and tested.
  • Possible disruptions in functionality (proximity detection, sound output of the actuator, secure standing, etc.) must be identified and resolved.
  • Troubleshooting is conducted using suggestions in the app.
  • Any necessary optimizations are made in the programming.
Final phase

Optional: Presentation and Allocation of Differentiation (with App)

  • The option for differentiation for advanced students is provided in the app: A main switch can be added using a reed contact. This allows the system to be set to "active" or "stand-by."
  • The further procedure is carried out using the app.

Plenary Discussion

  • Review of the project within the class group.
  • Presentation of the differentiated solutions, if applicable.

Competition

  • A sound measurement of the various solutions can be conducted as a competition (the loudest wins).

 

Information and notes
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Methodical and didactic tips

 

Differentiation options

For differentiation, an additional sensor can be integrated into the system. This allows for "disarming" or "arming" the system by triggering a reed contact. This should be mounted on the side of the system. The reed contact could also be visually enhanced by using a flat magnet attached to an "access card."

Motivational aspects

Securing objects is familiar to students from their everyday lives and brings intrinsic motivation. Independently implementing an actuator can lead to very creative solutions.

Additional material

In the introductory phase, brought-in locks (bike locks, Kensington locks, etc.) can be used. There must be objects to secure (e.g., a tablet, a book, etc.). 

Building instructions

Circuit diagram

Functions of the model and their technical solutions
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Functions of the Actuators/Sensors
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Technical solutions


Capturing a Secured Object
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Triggering a Button (Continuous Contact)


Undershooting a Safety Distance
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Detection by the Gesture Sensor


Output of the Warning Function "Safety Distance"
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Blinking of the red LED


Output of the Alarm Function
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Rotational Movement of a Motor with Sound Transmission
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Differentiation: Safety Shutdown of the System
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Contact via Reedswitch

Material list
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Material list for the basic circuit of the Bookstand
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Sensors

 

Functions

 

1 RGB gesture sensor

 

 

Motion sensor on approach

 

1 Button

 

Switch contact upon removal of the system

 

Actuators

 

Functions

 

1 LED, red

 

 

optical warning function
​

 

1 Gear motor

 

acoustic warning function

 



Material list for the differentiation task
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Sensors

 

Function

 

1 Reedswitch

 

 

Disarming the system
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