title: Connecting Serial Port Using Php
body: <p>Guys, </p>
  
  <p>for the below code, I am getting an error which says "Function Not Defined". I am unable to get what should I include to make it run. help will be really helpful.</p>
  
  <pre><code>&lt;?php
  $fd = dio_open('/dev/ttyS0', O_RDWR | O_NOCTTY | O_NONBLOCK);
  dio_close($fd);
  ?&gt;
  </code></pre>