VisibEL consists of a 2 meters long physical map of Sweden with 32 phono connectors (3.5 mm) spread across the country. The power plants and factories are represented by phicons covered with appropriate icons to represent what type they are. They are connected to the map as the picture below shows.
The factory in the picture above shines with a red light since it is consuming power while the nuclear plant shines with a green light since it is producing power. The cities also shines with a red light to indicate that they consume power.

We have implemented a Dallas one wire bus below the map and inside the plants we have placed a DS2408 8 bit io-device, each with a unique ID number. This allows us identify what is connected to the map as well as read and send information to each plant. This is used to control the LEDs and to read the status of the yellow "power grid cable".

On the map we also have three analog gauge meters, an alphanumeric LCD display and a soft button.
They are all controlled the same way as the plants, by means of several DS2408 chip that communicates via the bus with a USB adapter.
The LCD show turn number and amount of money left, the gauges show how much energy is produced and how much is consumed by factories and cities. The soft button is the "new turn" button.

Below the map three separate Dallas one wire buses reside and the three branches are programatically switched in and out by means of three reed relays that are also controlled with a DS2408 chip. This allows us to create three zones that we use to distinguish between how big the rivers beside the connectors are. This influences how much power the hydro plants generate.

The software that controls it all runs on an ordinary PC and uses the Java 1-wire API that is available from the maker of the one wire network. It is created with a model, view controller pattern to allow it to be tested even when not connected to the game board. Then a simplistic text interface to the game is displayed on screen.

For more information about how it works, see the project report in the download section.