[nazz]

Your solution is simple. However, it doesn't allow for as much modification as the original poster's idea. With his idea it could be modified in so many ways to add functionality because it wouldn't be limited by the technology. The solution you supplied will eventually be limited by the technology if the original poster wants to add other functions.

[pdkl95]

http://www.danielsen.com/jokes/objecttoaster.txt

> The second advisor, a software developer, immediately recognized the danger of such short-sighted thinking. [...] "A toaster that only makes toast will soon be obsolete. If we don't look to the future, we will have to completely redesign the toaster in just a few years."

[biot]

YAGNI. You can get to a 90% solution today at 10% of the cost and effort. If, later, you want to extend the system you’ll not only have learned a lot about the operations and failure modes of the current system, but hardware purchased later will be cheaper and may support even more functionality.

[evanlivingston]

Sure, but what is the value gain/opportunity cost between a simple, two hour installation that achieves a majority of the desired outcome with nearly rock-solid stability vs. sinking a massive amount of time into a bespoke and likely fragile system?

[kinsomo]

> However, it doesn't allow for as much modification as the original poster's idea.

My main point was the original poster's idea was probably focusing on the wrong kind of sensor for what he wanted to do. He could still network a bunch of motion sensors.

Also, I'd dispute the idea that my proposals were less "modifiable." If only because they're far easier to implement and a couple of orders of magnitude cheaper, so it's practical to replace if more capabilities are needed.

[Animats]

There may be a market for something between a standard one-bit low-rez motion sensor and a full color TV camera. Maybe a 16x16 pixel IR sensor with a fisheye lens and a puny CPU that reports an approximate number of people in the area, for HVAC and lighting control, and security.

[adrianN]

Reporting an approximate number of people is not a trivial task, even with a real camera. Depending on what exactly you mean with "approximate", of course.

[Animats]

0, 1, a few, many. Just enough to tell you how much to crank up the HVAC.

[kinsomo]

> 0, 1, a few, many. Just enough to tell you how much to crank up the HVAC.

I don't think the number of people in a room will give you meaningful information to tell you "how much to crank up the HVAC." Also, the HVAC systems in most homes aren't capable of even cranking up the HVAC in a particular room.

[Animats]

True. The market for this is schools, offices, and hotels, where the people load changes drastically and the HVAC has to react to that.

This is what the "Internet of Things" should be doing, but seldom does.