/*
  Blink
  Turns on an LED on for one second, then off for one second, repeatedly.
  
  This example code is in the public domain.

  modified 8 May 2014
  by Scott Fitzgerald
  
  modified 2 Sep 2016
  by Arturo Guadalupi
  
  modified 8 Sep 2016
  by Colby Newman
*/


// the setup function runs once when you press reset or power the board
void setup() {

  // https://www.arduino.cc/en/Reference/PinMode
  // https://www.arduino.cc/en/Reference/Constants
  // initialize digital pin LED_BUILTIN as an output.
  pinMode(3, OUTPUT);
}

// the loop function runs over and over again forever
void loop() {

  // https://www.arduino.cc/en/Reference/DigitalWrite
  // https://www.arduino.cc/en/Reference/Delay
  digitalWrite(3, HIGH);   // turn the LED on (HIGH is the voltage level)
  delay(500);                       // wait for a second
  digitalWrite(3, LOW);    // turn the LED off by making the voltage LOW
  delay(500);                       // wait for a second
}