我使用Highcharts来显示DHT22的温度 . 测量每5分钟发生一次，但在图表上我只能看到第一点的工具提示 .

脚本weather.php返回JSON数组

怎么了？

码：

<html>
<head>
  <title>Weather</title>
  <script src="/js/jquery-2.1.1.min.js"></script>
  <script src="/js/highcharts.js"></script>
<script>
var chart;
function requestData()
{
    $.ajax({
    url: 'weather.php',
    datatype: "json",
    success: function(data)
    {
           chart.series[0].setData(data.temperature);
           chart.series[1].setData(data.humidity);
    },
    });
}
$(document).ready(function() {
    Highcharts.setOptions({
        global: {
            useUTC: true
        }
    });
chart = new Highcharts.Chart({
     chart: {
        renderTo: 'graph',
        type: 'spline',
        events: {
            load: requestData
        }
     },
     title: {
        text: 'Monitoring'
     },
    tooltip: {
      shared: true
    },
     xAxis: {
        type: 'datetime',
            maxZoom: 20 * 1000
     },
     yAxis: {
        minPadding: 0.2,
            maxPadding: 0.2,
            title: {
                text: 'Temperature/Humidity',
                margin: 80
            }
     },
     series: [{
        name: 'Temperature',
        data: []
     },
     {
        name: 'Humidity',
        data: []
     }]
  });
  });
    </script>
</head>
<body>
  <div id="graph" style="width:100%; height:400px;"></div>
</body>
highcharts