php-linux-gpio/examples/basic.php

<?php

require_once __DIR__."/../vendor/autoload.php";

/*
 * This example will flash a led connected on pin 0 (GPIO17 on a Pi). If you are
 * not on a Pi, please change (or remove) the mapper below and update the pin
 * numbers to match.
 *
 */

use NoccyLabs\Gpio\Gpio;
use NoccyLabs\Gpio\GpioMapper\WiringPiMapper;

try {
    $gpio = new Gpio();
} catch (Gpio\Exception $e) {
    error_log("Error: {$e}");
}

// The mapper translates GPIO to logical pins and vice versa
$gpio->setMapper( new WiringPiMapper(2) );

// Access logical pin 0, since we got a mapper assigned. Otherwise this would
// be the actual GPIO0 pin. 
$led = $gpio[0]
    ->export()
    ->setEdge(Gpio::EDGE_NONE)
    ->setDirection(Gpio::DIR_OUT)
    ->setLabel("LED pin")
    ->setValue(0);

// Flash the led
$x = 0;
while(true) {
    $x = (int)(!$x);
    $led->setValue($x)->dumpStatus(true);
    usleep(500000);
}