As mentioned earlier, my project involves setting up a sensor gateway and trying to get sensor data through the ZigBee wireless protocol. As sensor gateway I’ll be using a Raspberry-pi computer:
This computer has the size of a credit card and can in terms of processing power be compared to a Pentium 3 computer. It’s been released in 2012 and it has build up some popularity as a media center device, but it’s also used a lot in electronic projects. Because of it’s low power usage, it’s ability to run Linux and it’s ability to directly connect to other electronics through it’s IO pins and USB ports, makes this board perfect for using it as sensor gateway. The board will run Linux and we will use it to collect sensor data and afterwards make the data available on the home network or even to online internet services. The R-Pi has an RJ45 ethernet port which allows us to connect our gateway directly to our home router. The sensor data will be collected wireless through the ZigBee protocol. ZigBee communication is in some way comparable with Wi-Fi and uses radio frequency waves. To use ZigBee I’ll be using XBee modules, one at the gateway side and one per sensor that I want to interconnect.
XBee modules support UART which is also supported by the Raspberry-pi board, and the R-Pi also provides the correct supply voltage so we can directly attach the XBee modules to the Raspberry-Pi, but due to the pin layout and size we will also need a breadboard and a breakout board and some electrical wires off course:
Currently I’m still waiting for the Raspberry board to arrive but the coming weeks I’ll spend some time exploring the ZigBee protocol by connecting XBee modules to my portable through the USB-port. I’ll also try to write a basic Java program which allows me to easily configure these XBee modules and with which I can send and receive data. Once again, wish me luck!