PComp Motor Lab and Final Project Idea
Now that the insanity of presenting for Red’s class is over, I can finally catch up with the last of the mandatory labs for PComp and figure out what I want to do for a final.
The Arduino microcontroller can only supply 3.3 v or 5v of regulated power, but with the help of a transistor it can also control high-current DC loads such as a DC motor or a light bulb. The transistor I used, the TIP120, acts as an electronic switch to provide higher voltage to the motor. Using pulsewidth modulation, we can also control the motor’s speed. The video below shows the speed of a DC motor controlled by a potentiometer.
I ran into some problems during the lab because the motor kept stopping every time analogwrite went beyond 130, roughly half the maximum speed of the motor. I believe it’s because the motor is draining too much power. Perhaps a capacitor would help?
Transistors are helpful, but an H Bridge offers even greater control of the DC motor by allowing the microcontroller to change the motor’s direction.
The H Bridge works really well, and I’m definitely a bigger fan of motors now than when I first started this course. I think it’s because when an object creates movement and sound it also incites empathy. This is why I love my roomba so much, and apparently I’m not its only fanboy. The roomba isn’t the best vacuum I ever owned, but the sheer fact that it moves on its own and cries for help when it gets stuck just tugs at my heart string.
Which leads me to what I’d like to produce for my final project. I notice from class discussions that people in general get frustrated when sensors and electronic devices don’t work. Whether it’s an MTA vending machine, an automatic door, or a water faucet, people expect those things to work perfectly and blame the device for flawed interactive design. We expect those devices to figure out what we want, and not the other way around.
Rather than reinvent interactions with electronic mechanisms, I’d rather inject behavior that would elicit more empathy on the user so the experience as a whole would be more enjoyable and the application in essence be more effective.
Introducing the pet curtain. It purrs like a servo kitten and is as temperamental as one too. It will only open if the user pets it gently with the right combination of force and speed. The user must avoid touching certain areas or else it will get agitated. I plan on using capacitive sensors, stroke sensors, and piezo vibration sensors as input, and servo motors as output. I may switch to stepper motors, but the sound of the servo really creates creature-like aspects that I enjoy.
I’d like to further explore injecting animal behavior into everyday items by creating an avian version that flies open when approached but returns if the user offers up a gift of bird seeds.
I never really noticed the politics, economics or gender dynamics of window dressings, but after some research I noticed that drapery is generally considered a feminine pastime. Take this company’s version of the history of curtains:
In all likelihood, somewhere in a Neanderthal cave, the lady of house figured out that the elements posed a problem and used animal hide to cover open portals of light. (via Natural Curtain Company)
How… British. Furthermore, because window accessories tend to be expensive, I suspect there is an economic rift between those who have them and those who don’t. But perhaps I’m mistaken and the difference is more cultural - traditional classic style vs modern minimalism maybe, or the climate isn’t suitable for certain types of window dressing.
As I further explore these ideas, I question whether this is treating animals as exotic subjects/gimmicks or it’s an examination of our lost connection with nature. I think I need to be more abrasive in these window dressings’ animalities. Yes, I am practically creating an electric sheep curtain that Deckard would cast aside. But if I can motivate the user to react as I do to this skit by French and Saunders then I’ll be a happy camper.
