Here is my first Spark.io project: An energy monitoring using both an Arduino and a Spark:
The Arduino is connected to my house power input, using CT sensors, and monitor the three phases and send them back to a server ( http://opensensorcloud.com/triggers/538a28292acae8177200001d ) .
Them, I use a Spark core as a kind of “remote display” for this:
It display the total instant power+ the three lines power.
Additionally is mesures also the temperature of the room, and send it back to the server too
The screen, a small cheap OLED display, shows the three lines values a bar graph on the right, a graphic showing the total evolution during the past half an hour and the local temp.
The RGB led of the core change also according to energy consumption: from green to red and provides an easy feedback on how much energy is currently used.
The Spark part + battery+ display is really small, so I am looking to an easy way to package this, if you have some ideas…