jquery and json return undefine

Hi.

I am building a project with a arduino Due that is to be a multiroom thermostat.

To control it, I want to use a web page with the Ethernet shield.

to extract data from arduino to web page, I want to use JSON and Jquery.

Note that I am a real newbe on both c+, HTML or jQuery.
So I follow step by step this video tutorial and tried adapt it to my needs :

jQuery json video turorial

It spit in 2 file the index.htm and main.js.

all the step by step was going good until it can to extrac data from the json data. the json var return ‘undefined’ like this:

here the code:
the index:

<DOCTYPE html>




<html>
	<head>
		<title>Home thermostat</title>
	
	</head>
	<body>
		<h1>jquery get temperature</h1>

		<h2>local temperature</h2>
			<ul id="roomId">

			
			</ul>

<script src="javascript/jquery.min.js"></script>	
<script src="javascript/main.js"></script>
			

	</body>
</html>

main.js

$(function(){
	var $data = $('#roomId');
	$.ajax({
		type: 'GET',
		url: 'http://192.168.0.110/ajax_inputs',
		success: function(data) {
			$.each(data, function(i, item){
				$data.append('<li>Room: '+ item.name +' : ' + item.temperature +'</li>');


			});
		}

	});


});

my json string have check ok with postman so I suppose it could have more with the buffer of ‘$data’ of something like that. but I post my json data anyway.

{"channels" : [{"name":"NAME 0","status":1,"canal":0,"temperature":22.70,"setPoint":5.00,"permission":0,"percentOut":0},{"name":"NAME 1","status":0,"canal":1,"temperature":23.02,"setPoint":5.00,"permission":0,"percentOut":0},{"name":"NAME 2","status":0,"canal":2,"temperature":22.74,"setPoint":5.00,"permission":0,"percentOut":0},{"name":"NAME 3","status":0,"canal":3,"temperature":22.48,"setPoint":5.00,"permission":0,"percentOut":0},{"name":"NAME 4","status":0,"canal":4,"temperature":22.55,"setPoint":5.00,"permission":0,"percentOut":0},{"name":"NAME 5","status":0,"canal":5,"temperature":22.63,"setPoint":5.00,"permission":0,"percentOut":0},{"name":"NAME 6","status":0,"canal":6,"temperature":22.68,"setPoint":5.00,"permission":0,"percentOut":0},{"name":"NAME 7","status":0,"canal":7,"temperature":22.68,"setPoint":5.00,"permission":0,"percentOut":0},{"name":"NAME 8","status":0,"canal":8,"temperature":0.00,"setPoint":5.00,"permission":0,"percentOut":0},{"name":"NAME 9","status":0,"canal":9,"temperature":-50.00,"setPoint":5.00,"permission":0,"percentOut":0}]}

Thanks.

this is a forum much more focussed on embedded software (only C++, basically). i would recommend to go to stackoverflow for any questions about JQuery or JSON.. your chances are probably much better there.