Ajax 提交一个按钮点击到 php，然后到一个串口设备

Question

我正在尝试通过 ajax 和 php 在串行设备（arduino）上启动一个功能的按钮，但似乎无法弄清楚。

这是我的html：

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script type="text/javascript" src="http://code.jquery.com/jquery-1.11.0.min.js"></script>
    <script type="text/javascript">
	$(function() {	
		$('#contact_form').on('submit', function (e) {	
			e.preventDefault();
			$.ajax({	
    			type: "POST",
				url: '/test/SubmitFormWORefresh.php',
				data: $('#contact_form').serialize(),
    			success: function() {
					alert('form was submitted');
      				
				}
  			});
  			return false;
		});
	});
	</script>
<meta charset="utf-8">
<title>Enroll</title>
</head>
<div id="contact_form">
<form name="contact" action="">
  <fieldset>
    <input type="submit" name="rcmd" class="button" id="submit_btn" value="Enroll" /><br />
  </fieldset>
</form>
</div>

这是我的 php：

<?php
$verz="1.0";
$comPort = "/dev/ttyACM0"; /*change to correct com port */
$PHP_SELF="index.php"; //This php file locate it from root

if (isset($_POST["rcmd"])) {
	$rcmd = $_POST["rcmd"];
	switch ($rcmd) {
     	case Stop:
		$fp =fopen($comPort, "w");
		sleep(2);
  		fwrite($fp, 1); /* this is the number that it will write */
  		fclose($fp);
  		break;
		
  		case Enroll:
		$fp =fopen($comPort, "w");
		sleep(2);
  		fwrite($fp, 3); /* this is the number that it will write */
  		fclose($fp);
  		break;
		default:
 		 die('Crap, something went wrong. The page just puked.');
	}/*end switch case*/
}/*end if statement*/
?>

当我运行它时，我得到一个对话框，说表单已提交，但串行设备没有响应它。任何帮助将不胜感激。

Answer 1

我更改侦听器以检测按钮的点击，并通过$(this).val() 获得值

Javascript：

<script type="text/javascript">
$(function() {  
    $('#contact_form').on('click', '.button',function (e) { 
        e.preventDefault();
        $.ajax({    
            type: "POST",
            url: '/test/SubmitFormWORefresh.php',
            data: 'rcmd='+$(this).val(),
            success: function() {
                alert('form was submitted');

            }
        });
        return false;
    });
});
</script>

HTML：

<input type="button" class="button" id="submit_btn" value="Enroll" />