5. Programming in Arduino IDE!

Now that we’ve set up our Arduino IDE, installed the proper drivers, and successfully connected our Arduino to the computer, we can finally move on to the fun part… coding our FBX robot!

But… where do we even start?

Before we dive into programming our FBX, we should first go through a basic example program in the Arduino IDE…

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Example Program: Blink.ino

Let’s have a look at the example sketch called Blink.ino.

Anytime you see the word “sketch”, we are referring to a program. Arduino calls programs “sketches”.

Go to File > Examples > 01.Basics > Blink

We will break down each part of this example sketch in detail so you have a better idea of how programming in Arduino IDE works.

Comments

Anything in light-gray is what is known as a comment. They do not actually affect our program, but they allow a programmer to…

• Organize thoughts about the code

• Plan out their code before writing it

• Communicate what a piece of code actually does (in simple terms). This is especially important when sharing code with others!

To make a single-line comment, we simply start our line with //:

// Hello! This is a single-line comment!

To make a multi-line comment, we surround our comment like /* this */:

/* Hello!
This is a multi-line comment!
We can have as many lines as we want,
as long as we surround it with the
symbols shown here!
*/

Setup() Function

The setup() function is called when a sketch starts.

We use it to...

• initialize variables

• initialize pin modes

• start using libraries

The setup() function will only run once, after each power up or reset of the Arduino board (any time we turn on the FBX!)

If you don’t understand the highlighted terms , don’t worry! we will learn about them soon.

Let's take a closer look...

pinMode() Function

pinMode() configures the specified pin to behave either as an input or an output.

In other words, we use pinMode() to tell our Arduino board whether a certain pin is an INPUT (like a button or a switch), or an OUTPUT (like an LED or a motor on our FBX).

loop() Function

the loop() function does precisely what its name suggests: It loops over and over again, allowing your program to change and respond in real time.

We can use it to actively control the Arduino board.

(And, by extension, our FBX!)

Let's take a closer look...

digitalWrite() Function

digitalWrite() allows us to write a HIGH or a LOW voltage value to a digital pin. If the pin has been configured as an OUTPUT with the pinMode() function, its voltage will be set to the following values:

• 5V (or 3.3V) for HIGH

• 0V (ground) for LOW

delay() Function

delay() pauses the program for the amount of time (in milliseconds) specified by the user in the parenthesis.

Since there are 1000 milliseconds in a second, a call to delay(1000) should pause our program for 1 second!

Similarly…

delay(500) = ½ of a second, delay(250) = ¼ of a second