The Color Mixing Lamp project uses three photoresistors covered with colored film. The voltage is proportional to the ratio of their resistances (they act like light sensors). I had to help Simon with the tiny pieces of film and and, when the project didn’t work, with inserting the cathode of the LED right. Everything else he did on his own. On video it’s difficult to see the LED lamp change its color because of that change in voltage (it was beautiful to see in real time) but the Serial Monitor reading does the job!
We also built the Mood Cue project which basically makes a potentiometer control a servo. It was quite a struggle to make this one work. It was Simon’s ingenious idea to change the ground and the power jumpers around as the order of the wires coming from the servo didn’t match the drawing. I noticed our decoupling capacitors were installed in a wrong way. When we changed those things, the servo finally gave us a sign of life.
The third project we did last week was Light Theremin. We made a light-based theremin using a photoresistor and a piezo element (sort of a speaker, which broke in the process). The end result was less annoying to the ear than the Arduino inventors had warned!