Last Day! 4/3

    In class on Thursday, we added some final touches to our book and presented it to the class. I was pretty happy with the final product, though there were definitely things that I would have liked to spend more time on. I recently watched some senior MAS and CAMS theses and there was a documentary about a studio art major. She perfectly articulated something that I often feel. She said that when she is creating something she envisions making a five-course Thanksgiving dinner, but ends up making a turkey sandwich and some jello. To some extent I felt that way about our book. I wish that we had had more time to focus on the aesthetics, but it was more important that we work on the actual engineering parts, since that was the assignment and the purpose of this class. Here are some pictures that Erin took of the book:

The lights flicker when you pull Hedwig past the candles

Mrs. Noris's eyes glow!

These pictures change when the characters either put on the invisibility cloak or take the polyjuice potion

Not the best picture, but the lights are either red or green depending on whether you went to page 4 and turned off the lights or not

    The other groups' final projects were very impressive. Cailey and Maria built a circuit that lit up when you snapped your fingers or made a noise by it. Essie and Frances made a box with lights on four sides. The light on bottom of the box was the light that lit up, so different lights turned on as you rotated it. Their design was nice because the way that the battery connected to the LED was cleverly simple, like Cailey and Maria’s lantern. I should learn from them, as I tend to overcomplicate things.
    During this project I learned something that I probably should have already know about myself.  My interests lie more in applied arts than they do in engineering. Something that pains me to admit, since I was hoping I could turn my passion for making things into a stable career path. While I like to know how things work, what I really enjoy is the actual process of just making something. During the process of making the book I really wanted to visit the book arts lab in the Clapp (literally the coolest place on campus) and learn about book binding and typesetting. But I realize that this has little to do with engineering, even if it would have made our project look cooler. I am glad that I at least have a base knowledge of how circuits work, so that I can possibly implement them in future projects, and I am still interested in learning more about Arduinos and microprocessors. I am glad that I learned how to use the laser cutter, but disappointed that I still have not gotten my hands on the 3D printer.
    I will leave you with one last link! Disney has created a new device called Touché that turns any surface (even liquid!) into an interactive surface. Of course, I don’t really understand how it works, but it has something to do with capacitance sensing. The video explains that most capacitive sensing operates at one frequency, so it can only sense if the user is touching or not touching. But Touché measures capacitance over a range of frequencies, so it can tell if the user is touching, pinching, grasping or not touching. Some of the applications seem silly or far fetched, but I do like the idea of using you body to control you phone or ipod. I just wonder what happens if you make an unintentional gesture. I think Touché is definitely something to watch, I am just surprised that it did not come from Apple or Google.

Pop-up 4/30

On Monday we were working on our pop-up book when our professor hinted that our project was not a real engineering project, but only a hobby. I don't think he anticipated the frustration and name-calling that would ensue. He said that our project was not interactive enough, something that would have been nice to know earlier then project. But, to be fair, not even we had a very concrete idea of where exactly project was going. I should have known that when we chose to make a pop-up book there would be the danger of me getting distracted and wanting to make it pretty, and our professor not taking it seriously. I left class that day extremely frustrated with the fact that we had made no progress on our project, and that we didn’t even have a strong concept.
    Over the week I tried to think about what the difference between engineering and a hobby really is. The term hobby just feels very condescending. It seems kind of arbitrary to me, and I think that it might have something to do with how useful what you are making really is. But it lead me to the realization that I do not have a concrete definition of what engineering is or isn’t. Engineering stills seems like a very broad and ambiguous term.  
    However, upon reflection I realized that I was setting the wrong goals for our pop-up book. I wanted to focus on the fun and pretty parts, and add on the circuits and lights as just another level of decoration. I realized that our professor was right, and that we did need to focus on making our book more interactive. I tried to think of ways to make our project more interactive within the context of a Harry Potter themed pop-up book and arrived at the conclusion that our pop-up book needed a plot, and that it needed to be a choose your own adventure. Perhaps it is an artificial way to prompt user interaction, but I liked the idea of choices that the reader making throughout the book affecting the outcome, which was whether Harry or Malfoy won the duel in the end. Furthermore, having a plot created a context in which our circuits made more sense.
    When we met on Wednesday night to finish our book, I channeled my frustration into bossiness. Luckily, Hannah and Erin were on board with my idea, so it didn’t take too much cajoling to get Hannah to do the illustrations while Erin and I worked on the circuits.
    Erin worked on the circuit for the first page, where Hedwig flies over some candles in the great hall, causing them to flicker. We already knew how to build a circuit that made the lights flash on and off, so we just added some photocells to it so that when you covered the photocells the flashing slowed down. Photocells are resistors whose resistance decreases as the amount of light shining on it increases. So the circuit pictured below is simply an oscillator with some LEDs on the output, and a photocell by one of the resistors. We have a voltage divider on the input because even though we decided not use batteries, our circuit only used between 0 and 12v instead of -12v and +12v. Consequently, the "ground" needed to be 6.

When we built the circuit on the breadboard, when the photocell was not covered the lights flashed so quickly that it looked as if they were constant, but when you covered the photocell the lights slowed down as if they were flickering. However, when we added longer wires so that the lights and the photocells would be on the pages I think it added extra resistance, so the lights slowed down a little and did not look constant when the photocell was uncovered. I suppose we could have put a smaller resistor somewhere in the circuit, but I think the effect was still convincing enough.  Erin also built the circuit for Mrs. Noris’s eyes, which were red LEDs.
    I worked on the circuit for the last page. Initially I imagined using metal plates as switches that were either in contact or not in contact depending on whether the a paper tab on one of the pages was pushed in or pulled out. But, I couldn’t really get it to work the way I wanted, so Erin decided that we should just use switches. The circuit that we used for the switches looked like this:

The less abstract version of the circuit that Erin drew looks like this:

If both of the switches are switched one way the lights on the last page are green. If they are  both switched the other way they are red. If the switches were switched in opposite directions the lights do not turn on at all. We tried to make it so that when you pulled the tab that opened the door on the fourth page, it also moved the switches. Unfortunately, we could not figure out how to make the distance that you pull the tab to open the door the same as the distance you need to move the switches. If we had had more time this is something that I definitely would have worked on. But, we decided to write something into the story prompting the reader to turn of and LED we attached to the switches before leaving the page. It kind of felt like a cop-out, but a least it worked.
    We decided to leave the circuits on the breadboard rather than try to solder them together. Then we taped the breadboard to the bottom of a box lid, and the pop up book on the other side. If we had had more time we could have explored ways to attach the circuit without out a breadboard (possibly crimping?), and how to make the circuit work with batteries instead of the power source. But we did what we could, and I was happy with the result.

Pop-up 4/27

   On Thursday we continued working on our pop-up book. At the beginning of class we set  concrete goals for what we wanted to accomplish in an effort to be more productive in class. We decided that we wanted to have the initial circuit that we were going to put in our pop up built, and a least have a very good idea of what we wanted the illustrations to look like. I still want to make multiple pages, but I know for sure that I am getting ahead of myself. At this rate we’ll be lucky if we get one done. But at the same time, I think that if we get one page done every other page will be easier. I even have a vague idea of how to do the battery. If there’s one thing I’ve learned this year it is that I need to dial back my ambition sometimes. I usually do not have the time or skills necessary to create what I want to, and I end up disappointing myself more than anyone. The thing about Wellesley is that no one teaches us how to set achievable goals. Every ten feet there are signs that say “Women who will make a difference in the world.” Why don’t they say “women who will be employable,” or “women who will be able to pay off their student loans.” Honestly, that’s all I really want.
    So, focusing on achievable goals, we worked on our circuit. Together we tried out different values of resistors to find the ones that made our lights flash at the right frequency. Then we decided to add a potentiometer to our circuit so that the user can change the rate that the lights flash, since interactivity is a requirement of this project. I think that pop-up books by nature are interactive, but perhaps not necessarily the page that we are working on right now, so this is definitely something that we need to spend more time on. When we were looking for green LEDs, all we could find were bicolor LEDs. They were actually perfect, because they are either red or green. Our professor changed our circuit so that now our lights change between red and green. I am still pretty confused about how this works, so I will have to look at it again, and perhaps I will have a better explanation later.
    In the meantime, Hannah worked on creating illustrations. She made Harry and Voldemort figures, and we cut them out using the laser cutter. Somehow, cutting paper with the laser cutter was even cooler than cutting plastic. I hope that I never have to use scissors again. It took some experimentation to figure out the right settings for cardstock in the lasercutter. Eventually we found out that you need to use 20% power, 1.3 velocity, and 1000 for the square wave thing (...which I think is called dpi?). We also looked through the multiple pop-up books that illustrate how to make pop-up books in the engineering room and found out how to make the figures stand up.
    Over the weekend Erin and I continued working on our pop-up book. I felt like we spent a ton of time on it (and we actually were focusing!) but got nothing done. I did cut out a Hogwarts shaped background for our Harry v. Voldemort page, and I also made a hippogriff. But, there I am getting ahead of myself again. The hippogriff is for a different page, IF we ever get around to making another one. What we need to do next is decide how we will actually attach the components of our circuits together, and how we will attach them to the batteries. From our last project we learned that this will probably take a long time.
    I know this, because I am still working on our last project. The approach that I explained in my last post was working...but I am having a lot of trouble getting the coils the right height so that the batteries and and wires and everything fit within the case, but there is also enough pressure to hold the batteries in the right spot. I was also having problems with some of our wires coming unsoldered, so I had to re-solder them, and I am pretty bad soldering. The only time I’ve ever really soldered was when I was at WTP, and we made jewelry. With some luck, I got it to stick together. I didn’t realize what a pain our lantern is to put together. On a scale of 1-10 for manufacturing, I would give it a -3. But I will chalk this up to a learning experience, because I have never thought about designing something that is easy to assemble before. I always just think about making something pretty. So, we still don’t have a working lantern, or much done on our pop-up book...and we only have two days of class left. I don’t know what I am going to do. On the bright side, the weather is still kind of cold, so its not so bad spending all of time inside working on stuff.