Christmas lights

As I was replacing one mechanical Christmas tree light controller that turns on/off lights at fixed times that no longer worked, it occurred to me that for next year, I could use a microprocessor like an Arduino to control the lights, and then I'm not bound by having to have the lights turn on at the same time each day. A quick search around shows there are many potential solutions. Most of the home automation stuff is too expensive (IMHO) for the type of application I have it mind, particularly since we have at least 4 different controllers (one outside, 3 in separate rooms) already. Now, the control stuff I will iterate on at a later time, but I was wanting to think about what would be needed for an Arduino to just turn an A/C socket on/off.

So, the ideas I've come up with so far include:

  • Buy a commercial unit that has an IR button to turn it on/off, and use an Arduino to act as the remote. Most of these have learning circuits, so I wouldn't have to reverse engineer the protocol for the remote (which isn't hard in any case). I would have to attach the Arduino IR emitter so that it stays focused on the control light, but that isn't hard. Figure about $5 (US) for the cord parts. Here is one such unit: http://www.ebay.com/itm/280848606944?ssPageName=STRK:MESINDXX:IT&_trksid=p3984.m1436.l2649
  • By the same vein, I could use a radio based solution, though there, the problem is figuring out what type of signal is used. I would imagine, one solution is to hack the remote control, so that it is controlled via the Arduino.
  • Use a relay and make my own wiring, as in Controllable Power Outlet - SparkFun Electronics. I really, really would prefer not to go hacking mains circuits wires. Also, if you follow their advice of using a GFCI outlet boosts the price than using an IR controller;
  • Adafruit offers a powerswitch tail (Powerswitch tail 2 : ID 268 : $25.95 : Adafruit Industries, Unique & fun DIY electronics and kits), which be ideal, but it is on the pricey side.
  • I could use the X10 controllers. I used these years ago, when I was doing a GCC port to an embedded target to control the board. I suspect, I long since got rid of them, since I no longer had the controller when I changed jobs, so I would have to buy new versions. However, if I had to buy new, the price kicks back up. Also, I remember vividly that in the old days at least, once X10 got your email, they would spam it forever.

Are there other solutions I missed that don't involve me hand making cables/plugs/etc?

There are various x10 vendors, some which may not spam. The cm17a firecracker seems an ideal x10 controller to use. There are some past post on the subject. A liberary file (x10firecracker.zip) has been posted for use with the arduino, but I haven't had a chance to try it.

zoomkat:
There are various x10 vendors, some which may not spam. The cm17a firecracker seems an ideal x10 controller to use. There are some past post on the subject. A liberary file (x10firecracker.zip) has been posted for use with the arduino, but I haven't had a chance to try it.

However, when I looked up X10 controllers, they were around $20 per switch. If I can buy the other solution for $5, I need more reasons to go with the more expensive solution. Maybe I'm looking in the wrong places. Of course with x10, I would only need a centralized controller on my laptop or desktop, and not a separate microprocessor.

And maybe the x10 company is no longer as bad as they used to be (I have one supplier I bought an $8 cable from, and they've been sending me 3 or more emails/day, and while I block some, they keep morphing the address so it gets past the filters).

Just get your X10 stuff off ebay. It's cheaper and you won't have to put up with spam. The problem with X10 is its reliability. With a year to work on it, I'd take a look at the Jeenodes as an alternative for Christmas lights. To control the power, get a relay and stuff it in a box to keep it away from children. You can also put a relay inside a power strip to make it safer.