You might want to try out "AJAX similar" approaches. For example JSONp (which stands for JSON padded)
Basically, you'll format the result in such way that it is wrapped in a native Javascript function call. There's plenty of info to be found on the net on JSONp.
It all helps solving the cross-domain barrier that "normal" AJAX calls suffer from, and it is easy to implement.
You'd just have to format your result like:
theNameOfYourCallbackFunctionDefinedInYourCallerPage({
"batteryLevel": "13.2",
"temperature": "7",
"LightState": "ON"
});
Granted, it is a bit more overhead than just outputting "batteryLevel:13.2|Temperature:72|LightState:ON", but it's not that much more, especially if you'd trim whitespaces and new-lines.