A Tarduino example done properly

main.cpp

#include <Arduino.h>  // Pretty much only here to giv us Serial Communications & delay()

#include "FooBar.h"

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Howdee!");
  delay(10000);   // What a silly way to rape a microcontroller...
}

void loop() {
  // put your main code here, to run repeatedly:
  Function1();
}

FooBar.h

void Function1();

Function1.cpp

#include <Arduino.h>

void Function1()
{
    Serial.println("Hi Grant!");
}