blink.php

<?php

require 'vendor/autoload.php';

use PiPHP\GPIO\GPIO;
use PiPHP\GPIO\Pin\PinInterface;

$gpio = new GPIO();
$pin = $gpio->getOutputPin(19);

while (true) {
  $pin->setValue(PinInterface::VALUE_HIGH);
  sleep(1);
  $pin->setValue(PinInterface::VALUE_LOW);
  sleep(1);
}