If you had doubts about the revolutionary changes in the cost and form factor of sensors, consider this “just in” from MIT Technology Review -- First Demonstration of a Surveillance Camera Powered by Ordinary WiFi Broadcasts -- a headline that promises WiFi-powered video cameras!
Yes, that’s right…but wait, there’s more: The camera may be the headliner of the story but the real key is that the test uses ubiquitous WiFi equipment to power not just cameras but potentially many other kinds of sensors as well.
This has obvious and immediate implications for home automation, of course. But clearly the same technology, a handful of COTS WiFi routers, can inexpensively power and link scores or hundreds of sensors across a manufacturing operation. As the authors point out, this would seem to be an enabling technology to bring the promise of the “things” to reality.
WiFi was already been getting plenty of attention in the IIoT world to begin with. As Craig Mathias of the Fairpoint Group has pointed out, while other networking technologies have had or seem to have a stronger orientation to manufacturing, WiFi (the chips in particular) are feature-rich and, thanks to the massive production volume demanded in the consumer market, are very cost-competitive.
Some of the additional merits which WiFi possesses, according to Mathias, are its low power requirements, compactness, growing ease of set up, scalability, IP-friendliness, and compatibility with existing infrastructure. [For more pluses, see Mathias’ article.]
Returning to the subject of WiFi-powered sensors, the technology is not, as far as can be determined, bound for commercialization just yet. But the barriers are few. One of those barriers is an FCC limit of only 1 watt for WiFi broadcasts, ensuring that the power available through WiFi will remain very limited. However, the researchers reached the obvious conclusion that antennas on sensors or cameras could significantly improve the amount of energy received by the devices.
Having a battery and charging system on board also improved device performance. The biggest success factor, though, appears to come from adopting a very limited duty cycle, e.g., only operating the camera (or any other sensor) every 30 minutes or so to reduce power use.
But non-continuous sensors would still be very useful in many applications. And when you add in the low-cost and wireless advantages of WiFi and power WiFi (or PoWiFi), it seems like a winning combination.
Alan R. Earls is a Boston-based writer focused on technology, business, and manufacturing — a field where he spent the earliest part of his career. He has written for publications and websites as diverse as The Boston Globe, Computerworld and Modern Infrastructure as well as Industry, The Manufacturer, and Today's Machining World.