That's funny, only because my cousin did this back in the 1980's.
Unfortunately, he used reed relays to determine when the runner was at the end. After a few days the magnet fell off thanks to it being stuck with the wrong glue and the motor ran past the end and jammed with power applied. Inevitably the armature caught fire after a couple of minutes [1] and set fire to the curtains.
Cue visit one evening by the fire bridgade and his entire bedroom being burned out and angry parents and insurers...
Edit: other misadventures we produced together (really need to put these on a web site as we have photos): lawn mower to stand up personal hovercraft (two broken fingers), radio controlled hovercraft bodged from above (sunk in middle of lake), rocket propelled grenade launcher (got bollocking from the police), RC plane missile launcher (set fire to grass), portable BBC micro (electric shock + fire), coil gun (remove metal swarf from finger at hospital) + more I can't remember off the top of my head.
Probably be in prison if we did it now. Hardware hacker culture has been going for a while now...
Would you not put a timer on the runner circuit and say "Do NOT run more than X seconds runner motor, otherwise we consider you drunk and you must go home"?
>[S]omething that seems like it should be a simple hack made mostly of a handful of $1 components turns into a huge and expensive clown-car mess unless you already have a fully stocked workshop. People who tell you how easy this crap is are invariably people who already have a drawer full of every resistor, capacitor and relay known to man, instead of having to spend days waiting for the turnaround on ordering the components they need. So yeah, projects like this probably are simple and only a couple of bucks if you've already spent twenty grand building out your electronics workshop!
Sounds like a pretty good argument for hackerspaces.
Back in the 80's and early 90's we had "junk shops" in the UK which were basically scrap dealers selling all sorts of weird shit. We'd go in our local one and be covered for bits in minutes.
We could even get small cannons (which were awesome when using firework gunpowder and marbles) in our local one for £2 a pop.
They still exist, at least in Ohio -- see Mendelson's (http://www.meci.com/), which is basically a giant warehouse filled from floor to ceiling with all sorts of weird bits and bobs. It's great fun to visit, or at least it was as of a few years ago when I last got the chance to swing by.
The hardware for this trinket is not an issue. You'd need something like an arduino, a temperature sensor, and the related motors to open/close the windows. Of course, a fair amount of wiring, unless you use something like the xbee.
The hardest part would be mounting the electric motors to the windows. I don't know what type of windows you have, but if they are single pane windows, a linear actuator will do the trick. Mounting a linear actuator is very simple, and mostly requires two brackets (one at each end). Other potential issue I can foresee is the window lock. But you could use a strong servo to actuate the mechanism.
One big, big issue about your system would be security. In case of a fire, the system might not allow for windows to be used an escape route. Though this only counts if you live in a one or two story house.
Why don't you take pictures of the windows and shoot them over to my email address? I can help you figure out the hardware side of things. (:
There's a simpler way to do it than using a bunch of relays to reverse polarity. What you're looking for is an H-bridge. It lets you use logic pins to reverse the polarity.
I did a similar project to control a motorized ham radio antenna mount on my truck. The mount came with this really silly-looking [0] controller switch that looks like a Hello Kitty product. I didn't want to velcro that crap on the dash of my ex-British military Land Rover so I built this board [1] to control the motor. It uses the SN754410 H-bridge and a Atmel ATTiny2313 that I flashed with Arduino code. I'd be happy to share the source and PCB with you if you want, jwz.
Why replace the control box, instead of controlling that? In the article it says: "but the power has to be off for more than a second to have an effect. Not quite as simple as simulating a momentary switch."
With an arduino and one relay, this sounds really easy, right?
Sure. And there are even simpler ways of accomplishing that.
But first you have to know that you can use an Arduino (pretty obvious). Then you need to know that you need a relay and what kind. And you need tools, connectors, enclosures, etc.
I agreed with some of what he said: getting started in hardware hacking can be expensive and complicated. But this is a side effect of how people get started these days. Jumping into hardware by building small radios (me at age 11) cost a few dollars and some scrounged parts and I slowly amassed tools and equipment over years. Jumping in by starting with microcontroller development immediately requires more money and equipment.
I think you would still have an artificial 1-second delay on any actions, which would be pretty annoying.
I assume this controller acts this weird way since it is supposed to plug into an X-10 system, and the only control in an X-10 system is to turn the power on or off. The obvious way to control it is to turn the power on to raise or lower, but without power, it's hard to maintain state to know whether you want to raise or lower. So instead, it is always powered on, and they use the on-off-on transition to trigger an action. About the typical level of hack for X-10 hardware.
If you aren't using an X-10 system, and want to manage the state yourself, all this is pointless, and I can see why someone would want to get rid of it.
That's what happens when you buy it as an add-on to a "home automation system," also known as license to pull money out of non-technical people's pockets.
Then again seeing how the hardware part jwz did do went for him, it's probably better he did get a purpose-built motor and microcontroller in a casing.
Everyone has to start somewhere! Keep up the good work.
I'm excited about seeing support for this beginner to intermediate level project on here. Hopefully this will encourage more people to try their hand at hardware and share the results with the community. Maybe I'll start sharing some of my smaller hardware projects on here...
I'd like to do a similar thing but controlling external shutters via an internal temperature or light sensor. The sensor part is trivial (pi, arduino, simple circuit, etc) but the tricky part for me is the motor controlled shutters. If anyone has a source on a set of shutters that can be motor controlled I would be most grateful!
It's because I have a house with an upstairs room that faces the sun in the afternoon, and closing the internal blinds helps but is not nearly as effective as external blinds, if there were any. However, since the room is not anywhere near reachable, my only option would be to have a hand-crank that goes through the wall. Ugh. Electronics to the rescue!
Unfortunately, he used reed relays to determine when the runner was at the end. After a few days the magnet fell off thanks to it being stuck with the wrong glue and the motor ran past the end and jammed with power applied. Inevitably the armature caught fire after a couple of minutes [1] and set fire to the curtains.
Cue visit one evening by the fire bridgade and his entire bedroom being burned out and angry parents and insurers...
[1] motors = dangerous ... http://www.youtube.com/watch?v=0o0SdmAwA7o
Edit: other misadventures we produced together (really need to put these on a web site as we have photos): lawn mower to stand up personal hovercraft (two broken fingers), radio controlled hovercraft bodged from above (sunk in middle of lake), rocket propelled grenade launcher (got bollocking from the police), RC plane missile launcher (set fire to grass), portable BBC micro (electric shock + fire), coil gun (remove metal swarf from finger at hospital) + more I can't remember off the top of my head.
Probably be in prison if we did it now. Hardware hacker culture has been going for a while now...