We won't have trouble with this project's requirements as we will use the same hardware and software that we used in the previous chapter. The details about the hardware requirements and configurations are given in Chapter 4, Monitoring Data Remotely.
All we need to do is to add a 5V relay on the board.
For more information about the relay, you can refer to its product link:
Pololu 5V relay module (http://www.pololu.com/product/2480)
The Pololu relay is a single-pole double-throw (SPDT) relay and is rated up to 10A under most conditions. SPDT relays are commonly used in electronics. They have two input pins for the coil, and three output pins to control electrical devices. SPDT utilizes a Zener diode for fast current decay. It also has two LED lights as coil actuation indicators.