| I like PoE, too -- ethernet in general is something that I think is pretty swell. But most people are not like us. They're not interested in wires, and many have grown up in a very connected world where there aren't any wires. Smart home sensors are already a pretty niche market. People who want smart home devices that use ethernet are a small subset of that niche. By the time we drill down to smarthome stuff that is powered with ethernet, we've lost almost everyone's attention. ... That said, I've made dumber things than this work. A facility I've done work at has a physical access control system that is "wireless". It's not really wireless, of course; it's got a fuckton of wire, but the comms are at least wireless. They wanted a pushbutton on their dispatch console's touch screen that could unlock the front door. Easy-enough, right? The console provides contact closures on the back end. But the "wireless" access control system's only useful interface for this was a stupid key fob, like for a car. It uses a CR2032 battery. It was, again, stupid. I hated it, but I used it anyway. I powered it with 12VDC that was stepped down with a fixed 3-volt linear regulator. I used some rather nice Japanese-made small-signal relays to "push" the buttons on the fob. Those little relays were, in-turn, controlled by the operation of the dispatch console's relays (which were located a couple of hundred hundred cable-feet away). It took a couple of hours to put it together. They paid the bill. It's been working fine for years. |