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.
-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.
Teachers! Did you use this instructable in your classroom?
Add a Teacher Note to share how you incorporated it into your lesson.
Step 1: Tone Out the Wires for the Door Contacts.
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
Step 2: Wire and Test
once the contacts are known its just a matter of hooking up the two wires to the phone and running them back to the controller
my red one was the common to the phone and ran back to the relay's common output. the black wire or the door contact wire went back to the normally open contact on the relay.
then i just stuck the wires on for power and paired the remote to the base as instructed by the manual that came with it.
Finally the test, pick up the phone and pressed the button on the remote and you should hear a satisfying buzzing sound.
Go down stairs (bring your keys just in case) go outside and try it from outside.
As a note the company claims a 200M range, I was skeptical if It would work in my building because of the concrete but im on the third floor and it works great.