[Mon Apr 30] Last Class Before Demo

Today was our last class before the final presentation. That was intimidating... Essie worked on the design a little more during the weekend and came up with a channel inside the dice so that the battery case can slide. The channel was necessary because otherwise the battery case could fall all over and jam the LEDs and other circuit parts. With the channel, we were able to control the path of the battery case. Although we were still having problem with lighting up the light on top when the connections were made at the bottom.

Given the one way channel we had, we could make our dice light up when landed on two sides but not the other two. Essie was saying that we could simplify our design and make a "shaky" dice that would light up different LEDs when you shake it in one of the two directions, although that would not be a dice any more...

Therefore, we asked for Oscar for his expectation of the complexity of our design because if we still want to roll our dice, then we would need to have two channels, which will make the structure extremely difficult (at least that's what I thought). Oscar had a discussion with everyone to see where every group was at. We also had a discussion of user interaction because that has been a little vague... Oscar said the user should be part of the process. By the user doing something to a machine and the machine does something back, the user should be able to react to the results of the machine. An example of a good user interaction is Maria and Cailey's project. They use sound sensor to detect the volume of the sound. If it's too loud, the red light would light up and the user will lower his/her voice accordingly. If the volume is within the standard, no light would light up so the user knows that he/she is not too loud.

Therefore we concluded that we should make our dice roll instead of just "shaky" to make it slightly more interactive although we are missing the piece where the user can use the results coming out of the machine. I guess it could possibly motivate you to roll again and keep playing with it. I did think again about our "screaming" idea - the dice will scream if it is lifted up so the user would know to put it down. But at this point, I am not sure whether we will have the time and energy to integrate sound in our design.

Anyways, in order to make it roll, we need to have two channels and two sets of battery cases. That was completely out of my capability of mapping and Essie successfully designed the two channels in a relatively short time.

We also had a revised version of our battery case since our channels were smaller than the battery case we built last week. It was still made of small identical pieces wired together.

Taken from Essie's blog.

Drawn by Essie. We were going to make a prototype of the battery case but we used all four button batteries that we had. You can see the battery case in our final project pictures.

Here is a picture that has a slightly better view of the batteries:

We cut the pieces and assembled the battery case. We experimented it in the channels that we have. The battery case would not slide very smoothly but the general intuition was right. Therefore, we just needed to make the battery case pieces were even smaller.

While Essie was working on Inkscape, I thought more about the connections and kept bringing up problems so that Essie could take them into account and tried to fix them with the structure design. I was concerned whether we were in the right direction to spend so much time on such a complicated structure design like our lantern project, but Oscar said the structure is always harder than the circuits...

Meanwhile I tried to find a way to connect metal pieces with acrylic to make connections. I tried Glue-All, but it didn't work. Hannah trained me to use hot glue guns. It was really fun to use but it still didn't really work. Double-side tapes would work fine but we don't seem to have them in the lab so we will have to think about some other methods somehow...

Then class ended... Next time we met up, we already had our basic structure done. Well, basically all done... We added some features to our structure to integrate the LEDs in our design:

Each small piece from the left is used to "close up" the openings of the channel. Actually, they are used as a platform for LEDs. The two legs of LEDs go through the holes and were bent back inward in a hook shape: 

Taken from Essie's blog.

Look very carefully on the top of the inner structure. You can see the hook shape LED legs.

We (sort of) solved the problem of "battery case can't free fall" and "can't stick metal piece to acrylic" by simply lighting up the lights on the bottom. In that case, we can simply complete the circuit inside the battery case so when it touches the LEDs, the LED lights up.

Here is the design layout from Inkscape:

Final project:

(I was going to cut it but the first part was kind of funny... Anyways, starting from 0:22 is the real demo.)

Please refer to the zip. on the class website for detailed Inkscape design and instructions.