使用php发布http请求到arduino响应是出乎意料的

Question

HI I am using curl to do a http request to my arduino, the arduino is firing a response the last line captured from wireshark shows 1023.

however mywebpage always has a value of 1

here is my php curl command

<?php
//set POST variables
$url = $_POST['url'];
unset($_POST['url']);
$fields_string = "";
//url-ify the data for the POST
foreach($_POST as $key=>$value) {
  $fields_string .= $key.'='.urlencode($value).'&';
 }
rtrim($fields_string,"&");
 //open connection
 $ch = curl_init();
 //set the url, number of POST vars, POST data
 $url .= '&';
 $url .= $fields_string;
 curl_setopt($ch,CURLOPT_URL,$url);
 //execute post

 $string = curl_exec($ch);

 //   curl_exec($ch);

  curl_close($ch);
  echo $string;
  ?>

I am very much learning this as I go, do I need to set something else in curl??