Picture this. You’ve seen a thing on the Internet. Someone has made something. It’s cool. There’s a fritzing diagram and the source code on github. You want to make the thing yourself. You collect the parts needed to reproduce the thing. You study the diagram. You hook everything up carefully. You run the software, and, and, nothing. It doesn’t work. Why, dammit, why?
Before you turn to StackOverflow, or submit a bug report, you need to collect information about the problem you’re having. But how? Where do you start? What can you do?