Book Image

Building Wireless Sensor Networks Using Arduino

By : Matthijs Kooijman
Book Image

Building Wireless Sensor Networks Using Arduino

By: Matthijs Kooijman

Overview of this book

Arduino has been established as the de facto standard microcontroller programming platform, being used for one-off do-it-yourself projects as well as prototypes for actual products. By providing a myriad of libraries, the Arduino community has made it very easy to interact with pretty much any piece of hardware out there. XBee offers a great range of low-power wireless solutions that are easy to work with, by taking all of the complexity of wireless (mesh) networking out of your hands and letting you focus on what to send without worrying about the how. Building wireless sensor networks is cost-effective as well as efficient as it will be done with Arduino support. The book starts with a brief introduction to various wireless protocols, concepts, and the XBee hardware that enables their use. Then the book expands to explain the Arduino boards to you, letting them read and send sensor data, collect that data centrally, and then even control your home from the Internet. Moving further more advanced topics such as interacting through the standard Zigbee Home Automation protocol, or making your application power-efficient are covered. By the end of the book, you will have all the tools needed to build complete, real-world solutions.
Table of Contents (8 chapters)

Creating a standalone relay

In addition to reading the input pins remotely, you can also control them remotely. All the XBee modules support a digital output (low/high) and some also support PWM output (pulse width modulation, as used by analogWrite in Arduino).

This section shows how to use a digital output pin to control a relay, letting you make a simpler version of the remote relay that you saw in Chapter 4, Controlling the World. Obviously, the wiring will be different as there is no Arduino involved anymore. The coordinator sketch will also need some modifications as the XBee module needs a different kind of a message to change its output pin.

When using the recommended hardware items, this example should look as follows:

Creating a standalone relay

Connecting things

Most of the wiring is the same as with the window sensor. You will need some kind of a breakout board and power supply. The relay module can be wired up by connecting GND and VCC/5V to the power supply and the relay control pin to the DIO1 pin on XBee...