<span class="hljs-comment">/*
  Blink
  Turns on an LED on for one second, then off for one second, repeatedly.

  This example code is in the public domain.
 */</span>

<span class="hljs-comment">// Pin 13 has an LED connected on most Arduino boards.</span>
<span class="hljs-comment">// give it a name:</span>
<span class="hljs-keyword">int</span> led = <span class="hljs-number">13</span>;

<span class="hljs-comment">// the setup routine runs once when you press reset:</span>
<span class="hljs-function"><span class="hljs-keyword">void</span> <span class="hljs-title">setup</span><span class="hljs-params">()</span> </span>{
  <span class="hljs-comment">// initialize the digital pin as an output.</span>
  <span class="hljs-built_in">pinMode</span>(led, <span class="hljs-literal">OUTPUT</span>);
}

<span class="hljs-comment">// the loop routine runs over and over again forever:</span>
<span class="hljs-function"><span class="hljs-keyword">void</span> <span class="hljs-title">loop</span><span class="hljs-params">()</span> </span>{
  <span class="hljs-built_in">digitalWrite</span>(led, <span class="hljs-literal">HIGH</span>);   <span class="hljs-comment">// turn the LED on (HIGH is the voltage level)</span>
  <span class="hljs-built_in">delay</span>(<span class="hljs-number">1000</span>);               <span class="hljs-comment">// wait for a second</span>
  <span class="hljs-built_in">digitalWrite</span>(led, <span class="hljs-literal">LOW</span>);    <span class="hljs-comment">// turn the LED off by making the voltage LOW</span>
  <span class="hljs-built_in">delay</span>(<span class="hljs-number">1000</span>);               <span class="hljs-comment">// wait for a second</span>
}
