Week 3: Digital Input + Digital Output

The project I ended up with this week was quite different than the project I had started with. Initially, after hearing the prompt last week, I had briefly considered trying to build a tic-tac-toe board. This, upon closer inspection of what it would entail, seemed like Too Much.

Instead, I implemented a switch that changed the speed of an LED when pressed, resulting in an increasingly erratic LED that finally settles on being on all the time. Maybe a metaphor for anxiety, but regardless, Too Simple.

*Finally,* I settled on a slightly more complicated iteration of the last idea: a contraption for blowing out LED birthday candles (inspired by a fan I found on the junk shelf).


First, I made sure my idea worked reasonably well, by setting up a row of LED lights on a breadboard to “blow out.” I had to finagle a bit with the Arduino code – I didn’t want the candles to blow out right away. It wanted it to feel as though a slightly asthmatic loved one was doing their best to knock out the lights and make a wish. The basic interaction was that the user would push a switch to turn on the fan, which, after a period, would blow out the candle. I played with the code a bit to make the switch unresponsive for a period of time after a button press to simulate someone sort of huffing/struggling to blow out the candles. After a certain number of presses, the candles would begin to flicker and later, give out altogether.

Once everything was working, I sent out to construct the birthday candles (straws courtesty of Sweetgreen!). I soldered some additional wire onto my LEDs so that they could travel length of the straws (which were shortened for my purposes.) I tested each LED within my circuit to ensure that they were still working after my clumsy soldering, and then covered the straws with blue painter’s tape.



To make the “cake,” I cut out a circle out of cardboard and made 5 small triangles at each spot I wanted a candle. Much easier than attempting to cut a tiny circle with an exacto knife.


I then attempt to create the LED portion of the circuit off of the breadboard, with mixed success. Mixed in the sense that it worked, but it was a MESS.


I have a lot to learn about properly managing wires / the organization of my circuit once I move off the breadboard. I found myself thinking, “There has to be a better way of doing this” quite often.

Here’s the whole contraption in action (the setting is intentionally a bit dark to help those LED candles pop):