Multiple Files

In Arduino, splitting out functionality into multiple files is easy. Let's start by assuming we have a file Main.ino. We can create other files in the format <name>.ino and the Arduino IDE will pick up the files when compiling.

For instance:

// Main.Ino

void start() {
  Serial.begin(9600);
  doSomething(); // works without manually including it
}

void loop() {}

// Testing.Ino

void doSomething() {
  Serial.println("Doing something");
}

The only caveat is that the extra files need to be in the same directory as Main.ino.

Sharing Enums

When it comes to sharing enums, the above recipe will not work, as we need the enum defined before a file is compiled. But, if using an enum and the method above, when compiling an error will occur where the enum will not be defined. So, we must create a header file and include it wherever it's used.

// Main.ino
#include "Types.h"

void start() {
  Serial.begin(9600);
  Serial.println(ButtonType::Solid);
}

void loop() {}

// Types.h
enum ButtonType
{
  Solid,
  Gradient,
  Program,
  None
};

There may be a better way to do this, but this works. I hope you found these helpful!