/*
 MultipleLEDsTimer2
 Cycle through three LEDs with a timer.
 This version uses a switch-case selection structure.
 */

const int delayTime = 500;  // time to wait between LED changes
const int led0 = 13;        // connect an LED to pin 13
const int led1 = 12;        // connect an LED to pin 12
const int led2 = 11;        // connect an LED to pin 11

int ledState;               // used to decide which LED is on (0 to 2)

void setup() {
  // make LED pins outputs
  pinMode(led0, OUTPUT);          
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);

  // initialize state
  ledState = 0;

  // turn the correct LED on and the others off
  digitalWrite(led0, HIGH);
  digitalWrite(led1, LOW);
  digitalWrite(led2, LOW);
}

void loop() {
  delay(delayTime);
  ledState = (ledState + 1) % 3;    // cycle through 0,1,2

  // turn the correct LED on and the others off  
  switch (ledState) {
    case 0:
      digitalWrite(led0, HIGH);  
      digitalWrite(led1, LOW);  
      digitalWrite(led2, LOW);        
      break;
    case 1:
      digitalWrite(led0, LOW);  
      digitalWrite(led1, HIGH);  
      digitalWrite(led2, LOW);      
      break;
    case 2:
      digitalWrite(led0, LOW);  
      digitalWrite(led1, LOW);  
      digitalWrite(led2, HIGH);       
      break;
    default: 
      digitalWrite(led0, HIGH);  
      digitalWrite(led1, HIGH);  
      digitalWrite(led2, HIGH); 
      break;
  }
}