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By Jack Ganssle

Let There Be Light, and IP

Summary: Forget PCs and embedded systems: light bulbs will soak up vast numbers of IP addresses.

NXP recently announced their "GreenChip" smart lighting product (, which gives each light bulb an IP address. A wireless network then manages lighting to garner more efficiencies. Now we can be even lazier and never turn off a light. Sensors can determine if there's motion in the room and take care of this routine activity. Dad won't have to yell at the kids to turn off the damn light!

It has been about 130 years since Edison and Swan built the first practical electric light bulbs. Indeed, the first commercial establishment illuminated by them was London's Savoy Theatre, home to Gilbert and Sullivan, in 1881. Since then uncounted billions have been produced, perhaps making bulbs of various types the most common electrical device in existence.

But how common? Curious, I inventoried our house, which, at 2400 square feet, is small compared to the US average of 2700 (according to I also toted up the number of PCs and products that certainly have one or more embedded microprocessors, such as remote controls, TVs, phones of various sorts, appliances and the like.

We have four PCs, one being a Mac and the others Windows machines. (Note that none of the kids live at home anymore, so their machines don't count.)

About 41 other products have embedded systems built in, though I suspect that count is a bit low. Though my woodshop abounds with electrical equipment only one drill and the radio are obviously smart. The tablesaw is deadly dim with only a universal motor, but microprocessors have made some saws so smart they pretty much can't injure the operator ( To see a Sawstop in action is impressive: the demonstrator pushes a hotdog at full speed into the blade, which falls under the table and is stopped by a chunk of aluminum in 5 msec. The hotdog gets a minor nick.

I didn't check the barn though the John Deere certainly has one or more processors, and the sawmill's digital hour meter must, too. We have a lot of two cycle-powered equipment out there, but I suspect none have micros.

But we have 118 light bulbs of various types, not including spares. I would have guessed 50.

Summing, that's 163 bulbs and computer-enabled devices. If each had an IP address, and scaling to the 130 million houses in the country ( gives 21 billion devices that could sport an IP address.

IPv4 is dead. Long live IPv6.

Published May 20, 2011