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Electric deadbolt — Parallax Forums

Electric deadbolt

tobdectobdec Posts: 267
edited 2011-12-12 15:44 in General Discussion
I live in an apartment complex, meaning I cant change the lock that matches the key provided to me. However I am working on implementing rfid to my front door for my fionce and I. I allready have my bs2 set up and coded and have the rfid serial reader with the rfid tags. My biggest issue is finding and internal deadbolt mechanismn that I can simply drop in place of the old one and leave the original front plate and tumblers. i am going to put my reader inside so they will never know I even set it up. With no changes to the tumblers and original faceplate you guys got any ideas? If I can't find an interal deadbolt mechanismn to fit my lock my only other options is a dual h-bridge chip and a step motor somehow attached to the inside knob, which won't be pretty and most likely not reliable. Any input on this?

Comments

  • ercoerco Posts: 20,259
    edited 2011-12-09 12:42
    tobdec wrote: »
    a dual h-bridge chip and a step motor somehow attached to the inside knob, which won't be pretty and most likely not reliable.

    Don't forget about supplying power to the whole kit & caboodle, which will be problemmatic at best, especially since it needs to be on at all times and won't work at all when the power fails/battery goes dead.
  • ElectricAyeElectricAye Posts: 4,561
    edited 2011-12-09 13:01
    tobdec wrote: »
    ...If I can't find an interal deadbolt mechanismn to fit my lock my only other options is a dual h-bridge chip and a step motor somehow attached to the inside knob, which won't be pretty and most likely not reliable. Any input on this?

    Instead of a stepper, could you actuate it with a solenoid? Just thinking....
  • xanatosxanatos Posts: 1,120
    edited 2011-12-09 13:48
    I'd agree with the solenoid idea. DEFINITELY make it with a battery backup/UPS so that you don't lock yourself out if you have a power fail. I'd just have a solenoid that was normally extended and retracted with the presence of the authorized RFID tag.

    While RFID is great, in reality you could have a very simple system with a hall effect sensor, and a transistor to drive the solenoid. Placing the hall effect sensor creatively would make it so simply using a magnet in a non-intuitive, non-obvious location, could activate the solenoid.

    Dave
  • ElectricAyeElectricAye Posts: 4,561
    edited 2011-12-09 13:54
    xanatos wrote: »
    ... DEFINITELY make it with a battery backup/UPS so that you don't lock yourself out if you have a power fail. ....

    Also, make sure you have easy access to some kind of manual over ride when you are inside your apartment. You wouldn't want to get trapped in your apartment during a fire.
  • hover1hover1 Posts: 1,929
    edited 2011-12-09 13:59
    tobdec wrote: »
    My biggest issue is finding and internal deadbolt mechanismn that I can simply drop in place of the old one and leave the original front plate and tumblers.

    That all depends on the manufacturer of the lock mechanism. You never mention it.
  • GordonMcCombGordonMcComb Posts: 3,366
    edited 2011-12-09 14:49
    I just went through this for a project, and what the others say about not locking you in is spot on. In fact, it is not legal to install a deadbolt on an entry doorway unless the deadbolt can be manually operated from the inside. The reason for such laws are obvious.

    -- Gordon
  • Mike GMike G Posts: 2,702
    edited 2011-12-09 15:31
    How about a magnetic door lock?
  • tobdectobdec Posts: 267
    edited 2011-12-10 07:41
    The whole lockout thing is one reason I want to leave the system completly intact. The whole solenoid thing is a little tough considering I literaly cant modify the mechanismn in any way. This is what I'm thinking, use the stepper and litteraly (I know it's ghetto) use a large rubber band behind the deadbolt knob on the inside. This way It'll grip tight when needed, but also slip in case of a failure. If the power goes out or there is some sort of failure with enough pressure from the key it'll just slip past the grip of the rubber band and open right up no issue. I beleive this will work bc the mechanisnm is well lubed and is butter smooth, it takes almost nothing to turn it ;) As far as ups/battery back up great idea guys! I didn't think about that until now, easy to set up and itl work great...we do have alot of power outages here. at Xanatos: i want to use RFID since i'm going for a "smart house" feel overall with all my projects...u know smart shelves...smart fridge, RFID on EVERYTHING! I'm even considering tagging myself later down the road idk yet, logging into my computer will be sooo much fun lol.
  • Mike GMike G Posts: 2,702
    edited 2011-12-10 08:41
    Here's another idea
    http://forums.parallax.com/showthread.php?128416
  • tobdectobdec Posts: 267
    edited 2011-12-10 11:18
    Thats a pretty awesome idea, but i like rfid better, theres no web interface that can be easily hacked.
  • Mike GMike G Posts: 2,702
    edited 2011-12-10 13:23
    Interesting opinion, ...theres no web interface that can be easily hacked, it's not a fact though.

    The purpose of post #10 was to show how someone else handled the locking mechanism.

    Out of curiosity, how will you deal with a lost or stolen RFID card?
  • tobdectobdec Posts: 267
    edited 2011-12-10 14:20
    Im sorry lol i typed that wrong...I meant to say a web interface is too easily hacked by someone who knows what they're doing. And as far as lost or stolen cards, i'll simply take them out of the BS2 or the data base i'll be using. I do love how he did that though, very cool idea, may have to incorporate somthing similar to that, only having some sort of slipper clutch so that my good ol' fashion key works.
  • Mike GMike G Posts: 2,702
    edited 2011-12-11 06:52
    Servos are energized and hold position while receiving a PWM signal. Without a constant 20ms pulse, the servo will not hold position. You can turn the key. The annoying servo will randomly twitching without a control signal. This can be fixed with a transistor switch on the servo power line. This concept applies to most motors. No power equals free turn. Saves energy too.
  • graffixgraffix Posts: 389
    edited 2011-12-11 07:34
    Heres what I got on my door Attachments_2011_12_11.zip

    I think they have a similar model with a xbee option
    zip
    zip
    Attachments_2011_12_11.zip
    4M
  • tobdectobdec Posts: 267
    edited 2011-12-11 09:32
    At Mike G.: Good advice on the servo twitch, never thought of that but it certainly would stop it.

    at graffix: How exactly does that work? And what does the Xbee serve in a door lock?
  • graffixgraffix Posts: 389
    edited 2011-12-11 09:51
    there is the keypad on the outside type in correct code and it unlocks the deadbolt.Reprogram new code with internal button.hold it down wait for beep,type in a new code and hit the button again and its set.From the inside the deadbolt is still intact with its original knob.Outside has the key.

    xbee's would allow you wireless control over the lock.Let your mom in when your at work or something.Also tie into home automation let you know from your bedroom if the door is locked or not.
  • PublisonPublison Posts: 12,366
    edited 2011-12-11 10:01
    I think there have been great solutions provided, but the OP specifically said he does not want to modify the exterior at all.
    My biggest issue is finding and internal deadbolt mechanismn that I can simply drop in place of the old one and leave the original front plate and tumblers

    I'm not sure there are options for that.

    At the very least, I believe it would need a dead bolt added. I think most landlords would all a dead bolt to be added, especially if their lock do not provide the proper security.
  • ChetChet Posts: 150
    edited 2011-12-12 06:42
    Graffix, I have one of those as well. There are jumpers / connections (in the lower part) that you can use to open or close the lock. From what I recall, it was just shorting the two points to actuate. I have the RFID and an SX board that I made to install, but my wife's sense of esthetics did not allow for permanent installation. I also used it with a BS2P and it worked fine. I did have a 6V gel battery as "UPS" for the processor.
  • tobdectobdec Posts: 267
    edited 2011-12-12 08:58
    I have a new aproach that would be pretty awesome and tie in to my apartment automation theme. What if I could use facial recognition? Obviously not on the BS2, but using my database servers to store facial patterns using some sort of software and output the data over an XBEE after the image is processed to tell my BS2 to open or not open based on the image. So heres my question, what facial recognition software allows for serial data output so I can send signals to my BS2? Roborealm possibly?
  • graffixgraffix Posts: 389
    edited 2011-12-12 09:25
    Now your talking:) I haven't a clue about that though, I'll see if I can't find something, probably not.I sent a email to someone perhaps I could get a good reply.
  • tobdectobdec Posts: 267
    edited 2011-12-12 09:43
    Hell yea, thanks graffix!
  • PublisonPublison Posts: 12,366
    edited 2011-12-12 09:48
    Of course, that would take the power of a PC for processing.

    OpenCV would probably be the best avenue to follow.

    http://opencv.willowgarage.com/wiki/
  • tobdectobdec Posts: 267
    edited 2011-12-12 09:57
    O beleive me I've got extra PC's and servers laying around...ima PC repair technician. Ill have to check out OpenCV later.
  • tonyp12tonyp12 Posts: 1,951
    edited 2011-12-12 10:07
    They make electronic door lock attachments that actually turn the real knob for you
    and the motor gears are such that you can override it and still turn it by hand in emergency.

    Just google: rfid deadbolt
    http://www.engadget.com/2007/12/13/rfid-deadbolt-system-also-features-remote-browser-control/
  • Spiral_72Spiral_72 Posts: 791
    edited 2011-12-12 15:44
    Maybe this has been mentioned, I didn't read all the posts.

    Home Depot and Lowes carry a ready made unit with a keypad. I've seen this system hacked to do exactly what you intend. In your case, it looks like you'll drop the keypad and just use the electric deadbolt. I THINK the solenoid was 24VDC, but don't hold me to it. I wanted to do the same, but I didn't get past the thinking about it stage :)
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