Week Two Documentation

Sometimes simple works best.

For my first physical computing project, I decided to make a light meter. I assumed that this would be a fairly complicated project.

I started with the basic LED setup that we made in class.


I then replaced the wire linking the LED to the ground with a photosensitive resistor provided in the Arduino starter kit.

Wax on,

Wax on,

Wax off.

Wax off.


This worked, but the light output was pretty dim. I decided to take up the current to the device by attaching four sensors in parallel. I stripped the ends of two wires, attaching four photosensitive resistors to one end of each,

Sensors on wires.jpg

and plugging the other end into the breadboard.

wires in breadboard.jpg

And that system did work to get more electricity into the LED. One of the major problems with this, though, was that if the positive end of one sensor touched the negative end of any other sensor, the whole array could be bypassed and the LED would go to full brightness no matter how much light was in the room. The result was an incredibly delicate instrument with no real practical use. To address the issue, I wrapped each of the sensors around a small wooden block and wrapped the whole thing in tape.

sensors on block.jpg

The end result was an input switch that measured light and held together fairly well.

Whole system.jpg

And that was pretty much it. The whole thing wound up being a lot simpler than I imagined it would be. It seems a bit basic, but it works. This feels like a good point to file this project under “Ain’t Broke” and call it a day.