This is my documentation of my first week of Physical Computing at ITP. What is physical computing? According to the syllabus:
Physical Computing is an approach to learning how humans communicate through computers that starts by considering how humans express themselves physically. In this course, we take the human body as a given, and attempt to design computing applications within the limits of its expression.
To realize this goal, you’ll learn how a computer converts the changes in energy given off by our bodies (in the form of sound, light, motion, and other forms) into changing electronic signals that it can read interpret. You’ll learn about the sensors that do this, and about very simple computers called microcontrollers that read sensors and convert their output into data. Finally, you’ll learn how microcontrollers communicate with other computers.
Physical computing takes a hands-on approach, which means that you spend a lot of time building circuits, soldering, writing programs, building structures to hold sensors and controls, and figuring out how best to make all of these things relate to a person’s expression.
For me, physical computing means building things with wires, circuits, sensors, switches and microprocessors. We are using Arduino microprocessors in class to control our creations. Our lab this week involved building a simple digital input/output system that makes two LEDs alternately flash when you press the switch.
Besides a photosensor theremin that I built in high school based on some plans I got off the internet, I have never really done any physical computing stuff before, hence my perplexed look in the photo above. I basically just set about recreating the plans in the lab instructions while familiarizing myself with working with the materials. The color-coded wires really help. Red is for power, black is for ground, and the light blue is for input/output signals.
Soldering was a little bit scary for me. We were supposed to solder the switch to two of the light blue wires. First, I wrapped the wires onto the switch, and then put everything in the helping hands. Then I melted some solder onto the iron to coat it, and then put the soldering iron onto the connection along with a bit of solder and melted it all together. It only took a couple seconds. My soldering job was ugly, but nothing exploded and the project worked, so I guess practice will make perfect.
Reading the resistors was a little bit tricky. Resistors have these little colored stripe patterns on them that tell you how many Ohms they are. They all kind of looked the same to me. I really had to squint to see the patterns. And I just got my eyes checked, so I don’t need new glasses. They are just really small! Note to self: I need to get a magnifying glass.
After I thought I had everything set up, the red light was flashing, but the yellow light didn’t do anything. Careful inspection revealed that I had one end of the yellow LED plugged in the wrong whole. Once again, a magnifying glass would have helped. Anyway, finally it worked!
Here is my successful project: