I was correct, Tuesday was a long night.

If I’ve taken anything away from this final, it’s the knowledge that fabricating anything is probably going to take longer than you think. It took Joe three days to build our miniature fan, but the results were amazing. The marionette had a lot of personality when it moved around and, in my opinion, really made the project. I’m still amazed that this was Joe’s first experience with any type of wood work. However, it had taken longer than either of us anticipated and we still had to build the wooden frame that we would mount the servo motors on.  We played around with the movement of our fan, acting as amateur mechanical engineers in order to figure out how big our frame needed to be and then spent the next few hours building it.

Finishing the frame at such a late hour, we were left with little time to mount the servos and figure out the mechanics of getting the marionette to move. We had a general sense of how it would work (mount one servo above it’s head to stand it up and mount another on it’s back to get it to raise it’s arms), but couldn’t be certain until the fabrication was complete. Fortunately, our plan was more or less correct. We had the right idea with mounting the servo above the fan’s head, but it needed to be well secured. Initially we planned to hot glue the motor to a wooden block attachment, but Eric Hagan informed us that probably wasn’t strong enough. He said that surrounding the motor with wood, so that we were bonding wood on wood, would be stronger and keep the motor in place. It worked likes charm. From there, it was a matter of figuring out the best starting position of he arm. We found that having the arm swing forward made a huge difference in getting the marionette to repeat the motion and stay balanced each time.

Getting the fan to raise his arms was a different matter altogether. We attached the wire to the arms, but found that we couldn’t get the arc of the servo arms long enough to raise them above his head (they only raised to his chest, which would have been awesome if we were trying to make an Egyptian mummy). With night turning into day, Joe and I were forced to improvise. We disconnected one of the arms and tweaked the wire, so that the motion resembled a single fist pump. Feeling satisfied with our fan’s motion, we installed  (i.e. duct taped) the FSR into the seat of a pair of Celtics warm up pants. By re-mapping the sensor, the standing/sitting dynamic was controlled by an actual person standing up and sitting down.

Unfortunately, we ran out of time and weren’t able to complete everything that we had planned. The fist pump motion was controlled simply by squeezing the FSR, instead of with a flex sensor installed in a shirt, which would allow the our fan to mimic the user’s actual fist pump. We had also worked with a Wave Shield, hoping to add sounds to the different movements. While we had figured this out from a technical standpoint, we did not have any appropriate sounds (like crowd noise or chants) ready to go, so it didn’t make sense to use it.

If you had asked me immediately after the class presentation, I would have said that I was done with this idea and ready to move on to the next one. However, after stepping away from it for a few days, I found myself thinking about ways to improve it and I may continue to work on it during winter break. I’m very interested in learning how to use the Kinect and figuring how to control our fan with it seems like a good place to start.

Over the weekend, Joe and I worked on making our remote control sports fan a reality. After brainstorming a number of ideas (including using a wind puppet controlled by a literal fan), we settled on making a balsa wood marionette controlled with servo motors. We decided to split up for most of the time, with Joe working on the fabrication and myself figuring out how to control the Servo motors. I thought that this wouldn’t be too difficult, since I’d worked with one for my Stupid Pet Trick, but I ran into a power issue. Since we’re trying to control multiple servos with multiple inputs, the 5V from the Arduino weren’t enough, so I needed to connect the setup to a 12V adapter. This did the trick. The servos are working and we’ll need to wait until we’re further along with fabrication to move forward.

On Saturday night I started working with the Wave Shield. Joe and I wanted to add some sound effects that would be triggered by the marionette’s movement, as well as maybe some other type of interaction. I’d never worked with any type of shield and quickly realized it wasn’t simple to use as I thought. I was under the impression that the shield was merely an adapter that would allow me access to all the pins on an Arduino. Not the case. I was going to have use a second Arduino that was dedicated to the Wave Shield. Fortunately, Robbie Hilton has been working with the same shield for his final and was able to give me a few tips. The documentation provided incorrectly lists which pins are available, which thankfully Robbie had figured out through trial and error. Using example code from Adafruit’s site, I was able to write a program that played four different sounds. To test it out, I connected it to a set of four switches, each controlling a different sound (see pictures/video below). Once I knew it worked, I then I replaced the switches with digital outputs from the original Arduino. When the FSR detected a value high enough to move the servo arm, it would change the digital output to “HIGH”, triggering a sound.

The next step is going to be tying together my work with Joe’s and fine tuning the code so that the servos accurately control the marionette created. Tuesday is going to be a long night.