In this, the first of a 2-part series, we describe how to build and test a pair of wireless data communications "nodes". Each node is based around "XBee" radio modules from US company MaxStream, Inc (www.maxstream.net). All parts, including the XBee module, are carried on a small PC board that’s designed specifically for experimenters.

With only a minor change, the XBee module can be connected to either an on-board PICAXE microcontroller or an external computer. This means that 2-way PICAXE-to-PICAXE or PICAXE-to-PC communications are possible, opening up a vast array of remote control and sensing applications.

You don't need to be an expert to build a reliable 2-way radio link - just a pair of these new boards from Revolution Education! Being PICAXE driven, they're dead easy to build and program and have a myriad of serious applications.

Construction is very easy, as the XBee modules are pre-built and simply plug into header sockets on the PC board. These radio modules utilise the "ZigBee" standard for ultra-low-power, high-reliability, short-range wireless communications (see the ZigBee feature in February 2006 SILICON CHIP for more information).