Getting Started with Arduino

How Does This Work?

I have introduced two new concepts with this example program: functions that return the result of their work and the if statement.

The if statement is possibly the most important instruction in a programming language, because it allows the computer (and remember, the Arduino is a small computer) to make decisions. After the if keyword, you have to write a "question" inside parentheses, and if the "answer", or result, is true, the first block of code will be executed; otherwise, the block of code after else will be executed. Notice that I have used the == symbol instead of =. The former is used when two entities are compared, and returns TRUE or FALSE; the latter assigns a value to a variable. Make sure that you use the correct one, because it is very easy to make that mistake and use just =, in which case your program will never work. I know, because after 25 years of programming, I still make that mistake.

Holding your finger on the button for as long as you need light is not practical. Although it would make you think about how much energy you're wasting when you walk away from a lamp that you left on, we need to figure out how to make the on button "stick".