Thesystem is a wireless 2.4 GHz radio module with an ATmega168 inside. The starter kit comes with two sensor nodes with built-in battery holder and one “hub” which interfaces to (and runs off) USB:
The daughterboards showing on top are the actual modules, the rest is part of the starter kit, i.e. sensor node and hub interface boards.
Several software examples were included, with hex files ready to try. It took me a while to figure out that I had to also set up the fuse bits – as delivered, the 168 is completely empty:
And just changing some ’s to /‘s in the source was all it took to re-compile these examples from source on MacOSX (the actual radio driver code is linked in from a library, no source, though).
Having a fully programmable chip to customize, with over half of its memory free makes this a more flexible option than XBee’s, at about the same price.
First trials indicate that the range of these little modules is a bit limited. They didn’t maintain a connection across three layers of stone & concrete (floors / walls) – a hefty requirement, but all within a single home. Still, it’s impressive what a pair of tiny on-board antennas can accomplish.