At 00.37 2012.03.14, you wrote: >On Tue, March 13, 2012 4:18 pm, Josh Koffman wrote: >> Hi All. >> >> I've been asked to help with a bit of background research for an idea >> a friend of mine had. He wants to do some data over powerline >> transmissions. This isn't long distance (it would be within the same >> building). A few years ago I would have said that it wasn't going to >> be that possible, but with the number of broadband over powerline >> devices and the plethora of home networking extenders that use power >> lines, maybe things have changed? >> >> I've been doing some searching around, but as with most things network >> related, I'm not finding a ton of really useful info out there. Then >> again, maybe I'm just missing it. His specs aren't too demanding. >> Speed is somewhere between 100-300kpbs. Might be able to tolerate >> lower. Bi-directionality is a plus. Low cost is also a consideration, >> so if there are expensive transformers or the like involved, that >> might not be too good. >> >> I'm going to keep searching, but if anyone has any pointers, even just >> to manufacturers that do this kind of stuff, I'd appreciate it! > >Microchip has a development board that uses powerline communications: >d= =3D1406&dDocName=3Den553054> >It runs on a dsPIC33. There are other powerline solutions that don't use a >general purpose chip, but the dsPIC solution is the only one I've worked >with. > >Powerline communications is challenging- particularly if you are trying to >stay in one of the "approved" bands (below 130KHz, for example). By >design, AC power is very low impedance- in the milli-ohms, typically up to >at least 1 MHz. Add to that all the other noise on the line- getting >reliable communications is not trivial. And it costs energy. As far as I know it's not a cheap way to transmit data= , well at least my powerline-based LAN endpoints get very hot, of course thin= gs are less demanding when turning on or off seldomly lights and home applianc= es. >Don't forget the "not kill yourself" part. When you're playing with mains, >the risk is *REAL*. > >Matt Bennett >Just outside of Austin, TX >30.51,-97.91 > >The views I express are my own, not that of my employer, a large >multinational corporation that you are familiar with. >--=20 >http://www.piclist.com PIC/SX FAQ & list archive >View/change your membership options at >http://mailman.mit.edu/mailman/listinfo/piclist --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .