/*   Blink    Turns an LED on for one second, then off for one second, repeatedly.    Most Arduinos have an on-board LED you can control. On the UNO, MEGA and ZERO   it is attached to digital pin 13, on MKR1000 on pin 6. LED_BUILTIN is set to   the correct LED pin independent of which board is used.   If you want to know what pin the on-board LED is connected to on your Arduino   model, check the Technical Specs of your board at:   https://www.arduino.cc/en/Main/Products    modified 8 May 2014   by Scott Fitzgerald   modified 2 Sep 2016   by Arturo Guadalupi   modified 8 Sep 2016   by Colby Newman    This example code is in the public domain.    http://www.arduino.cc/en/Tutorial/Blink */  // the setup function runs once when you press reset or power the board void setup() {   // initialize digital pin LED_BUILTIN as an output.   pinMode(LED_BUILTIN, OUTPUT); }  // the loop function runs over and over again forever void loop() {   digitalWrite(LED_BUILTIN, HIGH);   // turn the LED on (HIGH is the voltage level)   delay(1000);                       // wait for a second   digitalWrite(LED_BUILTIN, LOW);    // turn the LED off by making the voltage LOW   delay(1000);                       // wait for a second }