// create curl resource
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_POST, 1);

    // set url
    curl_setopt($ch, CURLOPT_URL, "https://api.spark.io/v1/devices/YOURDEVICEIDHERE/led");

    // set oauth access token
    curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query(array('access_token' => 'YOURACCESSTOKENHERE')));

    // return the transfer as a string
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

    // $output contains the output string
    $output = curl_exec($ch);
    print_r($output);

    // close curl resource to free up system resources
    curl_close($ch);