For the first assignment for Physical Computing (pcomp) class at ITP, I built a digital input circuit and digital output circuit using a microcontroller module called Arduino. Eventually, it is a simple exercise that turn LED lights on/off when the switch is on/off.

I didn’t really understand how things work, so ended up doing very basic one that looks like this:

Basic circuit with 2 LED lights and a switch.

Basic circuit with 2 LED lights and a switch.

And after that I used tin foil around the switch, trying to see if any other material besides ready-made switch works.

And I also tried adding another LED light. Yay, they worked!

analog in and output

Left: Switch-off, Right: Switch-on

Here are some tips I learned for myself:

(1) Organize everything: I think it’s better if you lay out materials you’re gonna use before putting things together, so you don’t have to look for one piece of resistor while you have to hold something else.

It's always better to layout what you need beforehand.

They will make your life easier..

(2) Differentiate connections with colored wires: Use Red, Black, Blue..wires to differentiate “power” and “ground” and “other wiring”, so you don’t mess up the flow. Usually Red=power, Black=ground, Blue,Yellow,White=others.

(3) Resistors color patterns: I didn’t notice in the beginning, but color of resistors do matter. I used Identify your Resistors Webpage to check if I was using the right one.

(4) Sothering: Always make the tip of sothering tool clean, or you won’t get nice results.

(5) LED has anode and cathode: LED is so tiny, but it has anode and cathode!

(6) Always ask for help: Ask someone for help if you’re not sure whatever you’re doing is right or wrong. I asked this nice guy at the lab(forgot his name…) about the sothering, which I’d never done before, and he kindly taught me and my classmates how to sother step by step.

Got help with sothering

Got help with sothering