In the previous article (Plans for Lego World 2015), I sketched the ideas we will (try to) implement for Lego World 2015. But there will be more…
The Physical User Interface (PUI) for 2015 will be a card reader. All visitors can receive a unique ticket, containing a unique number and corresponding color pattern that can be read by the card reader. Something like this:
The card reader will have three color sensors on a row, reading the rows one by one. The first two rows (starting at the top with the black arrow) correspond to the number: 0 = yellow, 1 = green, 2 = red, 3 = blue. The third row is a CRC (normally the abbreviation for Cyclic Redundancy Check, but in our case it will be a Color Redundancy Check :-)) to check if the first two readings contain errors. It is not completely fail safe; if two colors are misread, the CRC can coincidentally still return OK. But the chance is not that big, and it is better than no check at all.
Once the card has been read, the computer display will shown the number and status of the candy delivery. The UI will be similar to the train or flight monitors, so the term Candy Arrival Monitor will probably show up somewhere in the code.
The first version we have planned, will not check if a ticket has already been used. Of course, you can keep track in a database if the card has been used. But we are thinking about a way to make it also physical visible for the visitor. For example that the ticket is punched like they used to do in the real train world.