Legos, Java, Programming Assignments and CS1 An assignment scenario

David J. Barnes The University of Kent at Canterbury [email protected]

http://www.cs.ukc.ac.uk/~djb/ ACM SIGCSE 2003

Context

 I use LEGO ® Mindstorms™ computer controlled models as a motivational tool.

– As additional material in my teaching.

– As part of a promotional talk to prospective students.

– With school children.

 Paper in SIGCSE 2002 on pedagogical issues with their use for teaching Java.

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Criteria for scenario selection

 The scenario should be interesting.

 Possibly grounded in the ‘real-world’.

 Rich in possibilities for discussion.

– Collateral learning is very important to me.

 It should present design alternatives.

– Software.

– Legoware.

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The Time-Team scenario



Caveat

: this is possibly not an original idea.

– OO = = reuse   A scenario for using arrays.

 The task is to ‘map’ an area in some way.

– Geophysical mapping by archaeologists.

– Ground-surface mapping for navigation.

– Mobile temperature mapping.

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Constraints of the scenario

 The data is to be visualised on a PC.

 The amount of data to be gathered is too much to fit fully in the model’s limited memory.

 Communication with the PC must be ‘face to-face’.

– The IR transmitter of the RCX must be directed to the IR tower of the PC.

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Host PC Tower Area to be Mapped

Discussion

 RCX to PC communication is not a problem: – rcxcomm package from DTU.

 Could the model read and transmit values one at a time?

 How can the model store a collection of values to be sent as a group?

 What sort of path should the model follow?

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Discussion

 How do we take ‘regular’ readings?

 What characteristics does the model need to provide values that are meaningful?

 Others?

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Implementation

 Once the issues have been addressed, a particular model could be provided.

– Plus software to drive the model at an appropriate level of abstraction.

– This keeps the focus on array manipulation.

 The host visualisation could also be provided – a simple JFrame with a JPanel .

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Extension ideas

 Use a temperature sensor for temperature mapping.

– Physical accuracy in the model is probably less of an issue.

– Readings may take longer.

 Since maps are often for the purpose of navigation, have the host instruct the model to go somewhere based on the map data.

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Summary

 Mindstorms models provide a valuable tool for creating credible real-world scenarios.

 Appropriate scenarios can provide a rich source for discussion as well as a vehicle for use of particular language features.

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