Let's see what we learned in this project. At the beginning of the project, you saw how to interface the required components of this project to your Arduino Yún board: a relay module, a current sensor, and a lamp that will be controlled by the Yún board.

Then, we wrote a simple sketch to test the different components of the project and made sure that they all worked correctly.

Then, we built the energy consumption logging part of the project, and logged the power consumption inside a Google Docs spreadsheet. We also used the built-in capabilities of Google Docs to calculate the actual energy consumption, total energy cost, and on/off time of the device.

Finally, in the last part of the project, we built a graphical user interface to control the relay from a web browser, from your computer, or a smartphone/tablet.

Of course, there are many ways to take what you've learned in this project and extend it further. The first thing you can do is to add more devices to the project. For example...