Basic example of publishing to PubNub from PHP. Really distilled down to just the REST calls.

basic-pubnub.php

<?php

$CHANNEL = "iot";
$PUB_KEY = "_YOUR_PUBLISH_KEY_";
$SUB_KEY = "_YOUR_SUBSCRIBE_KEY_";
$SECRET_KEY = "_YOUR_SECRET_KEY_";
$PUBNUB = "http://pubsub.pubnub.com";

$data = array(
    "count" => 3
);
$message = urlencode( json_encode( $data ) );
$uuid = uniqid();

$url = $PUBNUB . "/publish/" . $PUB_KEY . "/" . $SUB_KEY . "/" . $SECRET_KEY . "/" . $CHANNEL . "/0/" . $message . "?uuid=" . $uuid;

echo $url . "\n";

$curl = curl_init();

curl_setopt( $curl, CURLOPT_URL, $url );
curl_setopt( $curl, CURLOPT_RETURNTRANSFER, true );

$response = curl_exec( $curl );
curl_close( $curl );

echo $response . "\n";

?>