The increased application of software-controlled digital electronics hinders the understanding of how things work. The information train is a scientific experiment exhibit that physically demonstrates how computers communicate. It comprises a network in which a model Lego train acts as a physical carrier transferring a picture’s pixels from one computer to the other. The sending end computer scans a simple picture, and directs a model train to send that pixel to the receiving end computer. This is done by sensing the approaching train and switching a rail junction depending on whether a pixel is on or off. The train carries on its top a piece that rotates depending on the train’s route, thus carrying the data between the two computers. At the receiving end, two sensors detect the shape’s orientation allowing the receiving-end computer to reassemble the picture bit-by-bit, pixel-by-pixel. The receiving-end computer is a One Laptop per Child (OLPC) XO-1 machine, programmed using Etoys. This provides further opportunities for motivated adventurous children to interact with the experiment’s implementation.
KeywordsDevice Driver Digital Converter Analog Draw Function Sender Side State Machine Diagram
- B. J. Allen-Conn and Kim Rose. Powerful Ideas in the Classroom Using Squeak to Enhance Math and Science Learning. Viewpoints Research Institute, 2003.Google Scholar
- Claude E. Shannon. A Mathematical Theory of Communication. Bell System Technical Journal, 27, pages 379–423 and 623–656, July and October, 1948.Google Scholar
- Dave Thomas and Andy Hunt. State Machines. IEEE Software 19(6): 10–12. November/December 2002.Google Scholar
- Diomidis Spinellis. The Antikythera mechanism: A computer science perspective. IEEE Computer, 41(5):22–27, May 2008. (doi:10.1109/MC.2008.166)Google Scholar
- Fairchild Semiconductor. LM339/LM339A, LM239A, LM2901: Quad Comparator. Revision 1.0.5, 2012. Available online www.fairchildsemi.com/ds/LM/LM2901.pdf.
- B. Freudenberg, Y. Ohshima, and S. Wallace. Etoys for One Laptop Per Child. In C5 ’09: The Seventh International Conference on Creating, Connecting and Collaborating through Computing, pages 57–64, 2009. (doi:10.1109/C5.2009.9)Google Scholar
- M. Gaelli, O. Nierstrasz, and S. Stinckwich. Idioms for composing games with EToys. In C5 ’06: The Fourth International Conference on Creating, Connecting and Collaborating through Computing, pages 222–231, 2006. (doi:10.1109/C5.2006.20)Google Scholar
- Dan Ingalls, Ted Kaehler, John Maloney, Scott Wallace, and Alan Kay. Back to the future: the story of Squeak, a practical Smalltalk written in itself. In OOPSLA ’97: Proceedings of the 12th ACM SIGPLAN Conference on Object-Oriented Programming, Systems, Languages, and Applications, pages 318–326, New York, NY, USA, 1997. ACM Press. (doi:10.1145/263698.263754)Google Scholar
- Alan Kay. Our Human Condition “From Space”. In (Allen-Conn and Rose, 2003) pp. 73–79.Google Scholar
- Newton Lee. Interview with Nicholas Negroponte. Computers in Entertainment, 4(1):3, 2006. (doi:10.1145/1111293.1111298)Google Scholar
- Casey Read and Ben Fry. Processing: A Programming Handbook for Visual Designers and Artists. MIT Press, Cambridge, MA, 2007.Google Scholar
- Texas Instruments. ULN2002A, ULN2003A, ULN2003AI, ULN2004A, ULQ2003A, ULQ2004A: High-voltage high-current Darlington transistor arrays. December 1976, revised March 2012. Available online www.ti.com/lit/ds/symlink/uln2003a.pdf.
- Vishay Intertechnology. CNY70: Reflective Optical Sensor with Transistor Output. Document number 83751. Revision 1.8, July 2012. Available online www.vishay.com/docs/83751/cny70.pdf.