The sense of smell is an amazing function in vertebrate animals. Even the human nose, which is not particularly notable in comparison with other animals, is fascinating in its sensitivity to trace amounts of a large variety of substances. It has a level of selectivity and capability of distinguishing between different kinds of smells, which is very difficult to match by even the most sophisticated artificial sensors.
Having as the main motivation the enrichment of the IoT gadgetry sitting around in my house (and eventually fill up an entire 192.168.1.1/24 network address range), I found that (after the motion and entrance detection device), an interesting device to invest time on would be something capable of sensing multiple air quality parameters at the same time.
