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keyless apartment building entry

keyless apartment building entry
set up an RF receiver to trigger the door contacts on your apartment building from a keyfob.

I hate coming home in the snow, rain, and fumbling for keys and balancing grocerys, boxes, ect and trying to pull the door open and hold it while I wiggle the keys out.

so I decided enough was enough.

Materials needed

-one channel (minimum) RF receiver , I used a two channel just incase I needed the other one, but I don't.
I got mine from lightobject.com they have all kinds of cool stuff at great prices
- 12v dc transformer
-bit of wire

A multimeter is handy as well but not necessary.

and I used double sided foam tape to stick it to the wall

As far as I know this will only work on an older style door system thats all analog.
if your front door just has a row of buttons to call each apartment it will probably work.
If you have a newer system that calls your phone it wont.
 
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Step 1Tone out the wires for the door contacts.

tone out the wires for the door contacts.
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My building uses a 5 wire intercom system, there is 5 wires which are daisy chained from apartment to apartment.

To determine the proper wire combination i first used the multimeter to determine the state of the switch that opens when you pick of the phone. in order to trigger the door control module the switch must be closed momentarily.

Then i used a jumper wire from what i presumed to be the common control wire, and while holding the phone up to my ear i touched the other end of the jumper to the rest of the terminals until i could hear the magnetic contact at the front door buzzing.

In my case , terminals 6,11,10 are the common, and 9 was the door contact. The rest are voice and call wires.

The receiver i used was two channel, however only one is needed.

Because the door contact switch just triggers the controller all we need to do is to pulse the output
momentarily closing the contact which triggers the controller to hold the door magnetic latch open for the set duration of time.

I changed the jumpers on the board to momentary output so that when i press the button on the remote the relay closes just for a second and triggers the controller downstairs

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4 comments
May 20, 2010. 11:02 AMagis68 says:
I have the same "telephone" for opening the main door in my house...I will use your idea to make the same thing.....thanks....Very simple, easy, and convenient  
Sep 3, 2009. 5:12 AMiectyx3c says:
Clever and well done. Wish I had this at my old apartment. Thanks for the info on lightobject.com - really cool.
Apr 14, 2009. 11:43 AMBlackHatCracker says:
I like it! Good work!!!
Mar 23, 2009. 9:03 PMsome114 says:
wow, this is so totally cool. It would be even cooler if I could figure it out! lol, not that you did a bad job, I'm just 17 years old and not too sure if I could do that lol Nice work!

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Author:stuie25