This is a relatively simple HTML+JavaScript+PHP example of polling a Spark Core for sensor data and displaying the data in a graph using the Highcharts graphing library.
proxy.php is really only used to help hide the access
token. Replace the YOUR_ACCESS_TOKEN_HERE with your
Spark API access token. Also, replace all instances of
YOUR_DEVICE_ID_HERE in index.html with
the device ID of the core you wish to poll.