Cheap, simple garage door open/close sensors...

I know there are garage door close sensors, with the big fancy magnet and metal enclosed wiring.....well, ok, that's NOT what I want (mainly the buying more stuff part). This open/close detection is primarily for my amusement, not for security specifically.

What I'd like is simply an open/close sensor (aka a closed contact). I'd like to know when the door is fully closed and when it's fully open. So I figured some kind of sensor on the top of the door, and then the fixed sensor would go at the top of the garage door frame (for closed indication) and a fixed sensor along the rail the wheel rolls in (or coming down from the ceiling) for the open indication.

So here are some of my ideas:

1) I have some spare window/door magnetic reed switches. So I could somehow affix the sensor at the correct locations and put a magnet on the garage door. The magnet would probably have to be attached to something that holds it far enough away from the door so it doesn't interfere with the door travelling.
2) I could use the metal wheel guides that hold up the garage door as the "ground", and then use something to connect wires to that ground when its at its up and down travel spots. So, even just a bare wire would work if the garage door would push all the way up against it when it hits its travel limit. It'd have to be flexible enough so that the door pushes hard against it to get a good contact, but also move back to its original position when the door leaves.
3) I could use the open and close limit switches already on the garage door opener. While those wouldn't always tell me specifically where the DOOR was (if someone has disengaged the door from the shuttle), it should be very reliable and ready to go. The question is, can I just wire my digital input wires in parallel with the garage door limit switches, and will that harm or affect anything in the opener? If not, I'm thinking this would probably be the easiest way, and it will be very rarely that the door is disengaged from the shuttle (probably only when there's a power outtage, in which case, who cares about the sensors!)

any other suggestions? I'm ok with buying stuff from radio shack if I can't find it just laying around my house, but I'd rather make do with what I've got.

Well as someone that long ago went down the road of trying to use normal door contacts on my garage door... I will say I didn't have much luck.... the gap for the contact is not repeatable enough for that kind of door contact.

Then I realized that a good garage door sensor was relatively cheap and much more tolerable to the gap. Not worth trying to save a couple bucks.

Less than $13

http://www.automatedoutlet.com/product.php...at=0&page=1

As for using the limit switches... I would presume they have voltage running through them. Maybe even 110vac so be careful.

I use a regular set of door/window contacts (have been for years), when placed in the right location, they will work just fine. I tapped in to the limit switches for a while, using an X10 powerflash module, but ran into reliability problems. If you can get it to work with the Elk M1, let me know, as I definitely prefer that method. I think my limit switches had 6VDC running through them.

I agree with John, just get the wide gapped magnet sensors. If you are going through the hassle of running wires, mounting, etc... it would be worth the $32 to have something that works correctly.

I'm willing to bet some Cocooner may have some of these stashed in a parts bin that isn't being used...

Of course, only amateurs monitor one or two positions on their garage door. The 'pros' know the position of their door all the time within two inches (sorry, couldn't resist)

Anyway, the contacts will work well with your SECU16. Just attach the wires into a digital input and place the pull up resistor between the two terminals as well.

Yep, tried the cheap route didn't work when the wind would blow hard so I bought this one and attached it to an X10 power flash module and plugged it into the same outlet as the garage door opener. Has worked flawlessly for the last 6 or 7 years. I now have HomeSeer announce over the whole house speakers that the garage door has been left open if it's been left open after 9 PM. It also announces when the door is opening and closing and switches my camera to the garage so I can even see who's coming or going.
http://www.shop.all-systems-are-go.com/pro...2?productId=240

jwilson56 said:

As for using the limit switches... I would presume they have voltage running through them. Maybe even 110vac so be careful.

Click to expand...

Good lord, I hope not...it's 22 ga wire!

Yes yes yes, I AM a cheap SOB. But I also have TWO garage doors to do this to, so $64 is approaching money status, which means I'd need an official approval, and I already blew that recently on getting some TTS speakers in the house.

Should I measure the voltage across the limit switch contacts on the motor head to see what it is? Isn't it bad if you try to measure DC volts and it's actually AC?

How did you run into reliability issues using the limit switches, Dan? I'd think the switches themselves would be pretty reliable, or else you'd be having garage door problems. So was it the X10 part? I've got a Zreo Zeebox D250 and the secu16 for monitoring the inputs, all hard wired....is there a risk in connecting those in parallel to the limit switches? On one garage door, the limit switches are mechanical copper connections that touch, and on the other opener, they're magnetic reed switches.

I use standard window contacts with my garage doors and they work fine. I didnt attach anything to the doors. Instead, I put a magnet on the carriage (what the bracket to the door connects to) and hung a sensor from the rafters using metal straps. I was able to adjust the position of the sensors to by bending the strap to get within 1/4" of the magnet at each end of the track. Two doors, two different openers, and it's been working for months now.

Nice. I've got lots of spare metal strap, and hanging the sensor off the roof or wall would insulate it from jostling when the door goes up and down. So you just attached the magnet directly to the metal of the door? And no worries about it moving around during door operation?

I actually did the same thing dBeau did, except I used a small piece of wood instead of metal. And it does work 100%. I am pretty sure the reliability issue was because of X10, but I never got a chance to verify this.

So is the general concensus that it's not wise to parallel off the carriage limit switches?

If you do it right, there is no problem with it at all, but you might have to get an extra relay. It has been so long since I tried this, but I do have pics of the multimeter readings, will take a look at it when I get home.

If you want to do this on the cheap, go buy 2 per door of the 1085T-N - Surface Mount with Screw Terminals from AO for $2.39 each.

Mount the magnet on the top of the door.

With the door closed mount the sensor on the wall above the door - you may have to cut away some sheetrock to mount the sensor.

Go by a 1x4 that's 10 feet long.

Open the garage door and mount the 1x4 across the 2 tracks so you can put a sensor on it that will sense the magment on the top of the door. Use the other magnet here if it makes things easier.

I have used regular mag switches for many years with no reliability issues. On a wooden garage door at my old house and a metal door at my current house. I was using these as automation sensors, not security sensors, so a false alarm would not be the end of the world, but it never happened. If I was using them as security sensors, I would consider using the wide-gap switch for ultimate accuracy.

beelzerob said:

Nice. I've got lots of spare metal strap, and hanging the sensor off the roof or wall would insulate it from jostling when the door goes up and down. So you just attached the magnet directly to the metal of the door? And no worries about it moving around during door operation?

Click to expand...

I attached the magnet to the carriage that slides along the track when the door operates. There is an arm that connects the door to carriage (near the disconnect cord). This keeps the magnet up closer to the rafters, which keeps the length of the metal straps to a minimum. A downside to this approach is that if you are using it for security, the door can be opened after pulling the cord without causing the carriage to move (and change the state of the sensors). Of course, I managed to convince myself that this was a feature

I am not sure I understand, how can you open the door without moving the carriage? The carriage moves, no matter how you open the door (in my case).