VisibEL is a tangible map of Sweden modelling the electricity production. There are cities, placeable power plants and factories that can be connected to the power grid. It is an educational game which is based on scenarios. The main users are children between the ages of nine and twelve. By playing this game, children can learn about different types of power plants, how much energy they produce and how much they cost to build and run...
Please visit our website and visit us at the exibition IDXPO at Lindholmen Science Park.

Thursday, 29 April 2010

Super Busy

It's getting close to exhibition time and we are working hard to get everything ready. Right now we are doing "assembly line production" of all the power plant / factory phicons.

Also we need to get the map ready - attach the circuits for the three gauge meters, lcd display, bus relays and turn button. Also we need decide which attachment points belong to which bus and wire them up. On the top side of the map we need to visualize rivers, add the cities and do some more "beautification".

The software can now handle all the output and input (with the exception of the power grid connection cord that isn't detectable yet). There is still some programming required for the game logic but hopefully it'll be finished in time.

Monday, 19 April 2010

Were getting there

Today we built the power regulator circuit and attached it to a heat sink. We also got the LCD working and finished a program to display text on it.
Now we need to build the bus switching relay circuit and figure out why the demo program for the DS2408 is acting wierd when we try to use with the R/2R DAC connected to the gauge.
And do the main program...

Saturday, 10 April 2010

Gauge meter circuit

In my point of view, pull-up resistors for DS2408 are always needed. I did test on Friday, before I connected them(9 10k resistors), P0~P7 never become high. As long as I connected them as this picture show, I can controll P0~P7 for high or low.
The second photo shows the number of voltage after R/2R DAC and the after Opa.

1111 1111 4.80V -->1.93V
1111 0111 2.98V -->1.21V

Map circuit

Here is a link to a almost finished circuit for the map. The circuit pdf will be updated to reflect the current status of the project.

Notes for the schematic:
  • The OP-AMP has the wrong part nr, we use OPA337 but I couldn't find that one in Eagle.
  • The relays also has a wrong part number.
  • The circuit does not show that the site connectors also should have +5 and GND connected to the (only the 1-wire data cable, OW)
  • The LCD display has the wrong part nr, but it follows the Hitachi HD44780 standard

Thursday, 8 April 2010

Plant / City circuit

This is an updated version of the plant circuit.
The DS2408 data sheet recommend 470 Ohm instead of 220 Ohm in series with the LED Does it matter? Also the plug isn't exactly the one we use. The order on the 3.5 mm plug should be GND - OW - VCC counting from the plastic on the male plug to the tip of it.

And here is an idea of how to do the physical layout:

Tuesday, 6 April 2010

Software control

Today we have running lights controlled from a Java program and it works to connect and disconnect both the DS2408 I/O device and the USB-adapter.

I found some documentation about storing device IDs in a XML-file along with classification and we'll probably use this since it's nice to keep that data out of the code. That way it's easy to keep track of what DS2408 is supposed to represent a factory, what is supposed to be a nuclear power plant and so on...

Next on the todo-list is to dwelve further into how to control the bits on the DS2408. Now the code alternates the state but I want to set the state instead. Also have to figure out how to read the input bit connected to the wire that can be connected to the main power grid (+5).

It all seems quite doable right now!

Thursday, 1 April 2010

Interesting report

This paper by Nicolas Villar talks about a lot of things, but I was fascinated by the use of a "surface network" for the Dallas 1-wire we use, look especially at pdf page 81-84 (page number 63-66). It's a soft surface that you connect things to by driving "spikes" into the self healing rubbery material.

I don't think we can use this because of time constraints and the fact that we need three wires, not just two as they use, but it would have let us get rid of the 32 slot restriction and would look really cool!

New architecture

We now sucessfully have tried the Dallas 1-wire bus via a USB-adapter (ds9490R). The bus is hotpluggable so one can add and remove components and detect what is connected. Each component has a unique ID-number so everything can be identified. We will use this system to detect what power plants and factories that are connected.

One cannot detect where something is connected though, but we will solve that by dividing the bus into several spokes that can be connected and disconnected by means of a DS2408 that is a 8 port I/O port that drives 6 reed relays (will post a schematic for that later, but the basics is described here - see the switched network section). This way one can loop through the spokes and detect what is connected to each of them.

A new schematic for the powerplants and factories is displayed here. The IC DS2408 drives 5 LEDs and reads if the GRID-pin is connected to Vcc - in the game this is equivalent to connecting the power plant/factory to the main power grid, thereby getting or using power.
(The cities are actually wired the same way, they just don't have a plug, they are hard wired.)