This sketch demonstrates the use of the Scheduler library.

scheduler_due_example.ino

/*
 * 
 *  This sketch demonstrates the use of the
 *  Scheduler library.
 * 
 *  To use, you will need an Arduino Due or Zero,
 *  four LEDs, four 220Ohm resistors, jumper wires 
 *  and a breadboard.
 *  Connect the LEDs to a resistor, and the resistors
 *  to pins 11, 10, 9, 8 on the Due.
 *  Connect the cathode (short pin) of the LEDs
 *  The the Due GND pin.
 * 
 *  Written by Peter Dalmaris
 *  June 2016
 *  wwww.txplore.com
 */

#include <Scheduler.h>

int led_red = 11;
int led_green = 10;
int led_yellow = 9;
int led_orange = 8;

void setup() {
  // put your setup code here, to run once:
  pinMode(led_red, OUTPUT);
  pinMode(led_green, OUTPUT);
  pinMode(led_yellow, OUTPUT);
  pinMode(led_orange, OUTPUT);
  Scheduler.startLoop(control_red);
  Scheduler.startLoop(control_green);
  Scheduler.startLoop(control_yellow);
  Scheduler.startLoop(control_orange);
}

void loop() {
  yield();  // This is important. With yield, control will be passed to one of the other tasks.
            // The same can be achieved by calling the delay function.
}

void control_red(){
  digitalWrite(led_red, HIGH);
  delay(300);   // Control is passed to one of the other tasks.
  digitalWrite(led_red, LOW);
  delay(300);   // Control is passed to one of the other tasks.
}

void control_green(){
  digitalWrite(led_green, HIGH);
  delay(400);   // Control is passed to one of the other tasks.
  digitalWrite(led_green, LOW);
  delay(400);   // Control is passed to one of the other tasks.
}

void control_yellow(){
  digitalWrite(led_yellow, HIGH);
  delay(500);   // Control is passed to one of the other tasks.
  digitalWrite(led_yellow, LOW);
  delay(500);   // Control is passed to one of the other tasks.
}

void control_orange(){
  digitalWrite(led_orange, HIGH);
  delay(600);   // Control is passed to one of the other tasks.
  digitalWrite(led_orange, LOW);
  delay(600);   // Control is passed to one of the other tasks.
}