<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> }