-------------------------------------------------- From: "Olin Lathrop" Sent: Sunday, June 13, 2010 11:55 PM To: "Microcontroller discussion list - Public." Subject: Re: [EE] Radio Light Switch > Oli Glaser wrote: >> If it was just one switch it could be a lot more >> simple(no data on carrier, just OOK driven flip flop or something), >> but some sort of networking is needed here I think. > > Not encoding data on the carrier would be a bad idea even with a single > switch. However, you don't need much more than that, and I don't see > where > the networking comes in. > > As I understand it, you just want to turn a few lights on or off. Give > each > light a ID. Each message contains the ID, the on or off command, and a > checksum. Send each command a few times for better probability it will > get > there. There's a human in the loop, so if he hits the button to turn on > the > light and it doesn't, he'll just hit it again. > > This is a lot like your TV remote, except those usually work on IR instead > of RF. Most of the time they work, but when they don't you just hit the > button again. It's all one way communication. > > For that matter, why not use IR? Does the user really need to turn lights > on and off in other rooms with entrances around a corner? I agree no encoding is generally a bad idea and "networking" was the wrong term. I meant simple IDing really, with maybe some state feedback if using transceivers. At the moment the plan is indeed just to turn a few lights on and off so that's what I should stick to really, but there was talk of applying the switch to other uses, so a little more "intelligence" for adaption purposes in future *may* be useful, but certainly not essential and not worth a lot of extra hassle/cost. IR would probably work fine in the current setup, but the RXs have to be invisible, so even a small detector being visible may be a problem, plus there is a possibility it will get used for none line of sight stuff in the future. I will mention it though and see what he thinks. In any case, I have the components to build a couple of IR test boards to get going with now, and could always switch these over to RF later. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist